How to Stop Damp Mould & Condensation - a COMPLETE Guide

This is the result of a year's research into what causes damp mould and condensation, and how to solve it.
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Today's Toolkit*
- Thermpro TP-55 Hygrometer geni.us/zJfvew (Amazon)
- Thermpro TP-65 Hygrometer with outdoor sensor geni.us/8ahIKcl (Amazon)
Ebac 3850e geni.us/gaElYY (Amazon) or also available direct from Ebac bit.ly/38Iz1AH
- Meaco Desiccant Dehumidifier featured in video geni.us/glttA1d (Amazon)
- Karcher Window Vac WV2 geni.us/cyqBmiK (Amazon)
- My bathroom extractor fan bit.ly/2GoWomX bought from Extractor Fan World. I had an Envirovent before, again bought from them. It stopped working a couple of years after install and they replaced it without question - great service!
Useful Links:
- That RH graph from Wikipedia bit.ly/36BLyEV
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#damp #mould #condensation

[@SloopyDog]

I was born in 1947 we lived in a council house with a coal fire. We never had any damp or mould problems. We had an oven in the kitchen linked to the coal fire. My mother often dried clothes on a clothes horse put in front of the oven, and still no damp problems. We didn't have radiators all we had was a back boiler behind the fire to heat the water. Coal fires allowed the house to breathe. Later on, the council fitted a gas boiler and radiators. That's when the problems started, we started getting damp problems, the windows were always damp on the inside. Many years later I had a Housing Association bungalow, due to my health problems. The Housing Association in their great wisdom decided to insulate the loft to the current standard. A damp-proofing firm filled the cavity walls with insulation( pumped in). That was when the bungalow started getting damp problems. Mould started to appear on every wall. It became a constant battle to keep the walls mould-free. The windows were always streaming with water. My wife and I are in our late seventies and in very poor health, I try to keep windows open as much as possible, all the time in summer. We are causing more problems by having our homes over-insulated. The house needs to breathe. Cavity walls were designed to do just that. There is no great mystery as to why people have damp problems. Many people can not afford to heat their homes as due to an incompetent government fuel prices have gone through the roof. People on minimum wages and pensioners on a single basic pension, like myself are struggling to live. In this country, the rich get rich and the poor are forgotten about. The basic pension starts at £130, you don't get far on that. I would like to see if the Prime Minister or our overpaid MPs could survive on what I have to live on. THERE IS NO WAY THEY COULD.

[@CharlieDIYte]

Sorry to hear about the problems you face now and thank you for explaining how the situation has changed over the years. It was makes perfect sense given the need to ventilate houses.

[@steffananthonyholden2752]

The problem is there was no clear strategy initially with insulation measures - now under Pas2035 the government intends to rectify all of this - “there is no insulation without ventilation” which is the causation for most your damp and mould symptoms … measures installed in isolation never work effectively - there has to be a conjoined approach and strategy …. Much in the same as if you improve a cars BHP you must improve its breaking capacity …. The old open fire houses had a mass of ventilation via the stack so RH never had time to condense and air changes were at a rate of 2/5 …. Of course the only way to heat the property was with fossil fuel and this is now to be banned …. And just to add , the mechanical operation of ‘opening windows manual will never work , nor will trickle vents long term

[@kevinwalsh8483]

Got a stove fitted before Christmas used to have an open fire.. windows are destroyed now due to the chimney been blocked now. Always had clothes on the rads drying.. so annoying

[@zane___k7333]

Because the fire gives off a lot of infared heat. Which reduces relative humidity.

[@user-bz9cb8bp2y]

We have candles, gov calls it affordable heating in UK 😂❤️❤️🇮🇱

[@bobbobson4069]

This is by far the most comprehensive "documentary" on the phenomenon of damp/mould and how to reduce it. I really appreciate the astonishing amount of work that has clearly gone into the making of it. The science and home experiments are fascinating. I can honestly say that I really understand the whole phenomenon much better now. Well done! I have of course liked and subscribed as a result! (Marius Gudonis, originally from northwest London, but now working in Warsaw)

[@markbriggs729]

Another +1 for PIV. I Moved into an early 1900's bungalow in Essex a few years ago and humidity levels were getting up into the 80's through the first winter. At one point water was streaming from the single glazed windows, down onto the windowsill and puddling on the floor. You could sense it in the air as well, everything would feel damp and there was a constant musk. I installed an extractor in both the kitchen and bathroom and changed all the single glazed windows to double and although this did help with the build up on the windows it didn't have much effect on the levels. I then tried running a dehumidifier and although this was somewhat successful it was only whilst it was running. As soon as it stopped the levels rose again. Last year i went with a loft fitted PIV with no heat and almost instantly the levels dropped down into the 40's. Even through the worst of winter it only crept up to 60% a few times. I have it fitted in the hallway and you can notice the temp if you stand right under it but it's a small price to pay for having no condensation or mould in the house. It even seems to force the air into all of the rooms quite well under door gaps etc. I now have that running all year round, use extractors in the kitchen and bathroom and put the dehumidifier on next to the clothes horse when drying clothes inside in the winter with amazing results. Quite possibly the best purchase i have ever made. If anyone reading has similar issues in a similar property i can't recommend them enough.

[@MTechOver9000]

Hi Mark, I came across you comment here, thanks for this info. This was made 6 months ago, would you still recommend the system you have? Which brand did you go for? Many thanks in advance

[@That1ufo]

After a flood they say it takes months to dry out with dehumidifiers, was the house empty not heated when you moved in? The clothes horse was probably the biggest problem or rain coming in the walls, get a condensing dryer!

[@pavel9652]

The line of logic regarding dehumidifier is flawed. You wrote it was somewhat successful when running. So is the piv, because it somewhat works when it is running. I think there is another problem, just like people suggested, it was damp because being vacant for a long time or there is a leak. Check the plumbing. I lived in the house where there were THREE small leaks simultaneously, under the main hot tank, shower and the small hot tank in the kitchen. That had risen moisture levels significantly in all the locations without producing obvious signs of leak.

[@JayL123]

@markbriggs729 Would you need Trickle vents on the windows for PIVs to work? None of the rooms have ventilation holes in the wall but have trickle vents in the windows. We plan to change the windows and I wonder if I have to get tricke vents in it for the air to flow. Apologies if its a silly question, but the trickle vents are all dusty and mouldy.

[@YellowPinkie]

As a building services engineer, I can state that is the simplest and easiest to understand explanation of RH. Good work Charlie!

[@CharlieDIYte]

Thanks, Stephen I massively appreciate that!

[@andrewstones2921]

I agree with Stephen 100%

[@npr1300A8]

Brilliantly explained. Thank you.

[@joeslacker1020]

​@@CharlieDIYte Hey you say to have a ventalation system or an Air Conditioner to circulate the air, but what if it's in a rainy area and you have a heater on with the AC or it on fan mode in a travel trailer? I thought the cold air from the outside meeting with the warm air inside is what causes the moisture, so why would putting air from outside inside cause it to be less moisture?

[@kenleehk65]

Perhaps to add a bit more accuracy to that statement..."Relative humidity is the amount of moisture in the air relative to the amount of moisture air can hold, influenced by its temperature "....yes, the air pressure also plays a part in how much moisture air can hold at atmospheric conditions. However, changes due to elevation and weather may contribute to a certain extent, though not massively.

[@Smithb83]

Another excellent video Charlie, chock full of well researched info to help us homeowners overcome DIY issues. Love your channel 🙌

[@t190uk]

Charlie, you have out done yourself with this video!!! The amount of data you collected was impressive and goes above and beyond, well done mate very informative!!

[@davec.4726]

Thank you Charlie again another concise video explaining common problems albeit a "pesky" one we nearly all have. Nice to have somebody to actually EXPLAIN in detail whats going on.

[@hannahswann747]

Thank you so much for this incredibly helpful and informative video. I’m renovating an old stone house in Wales with soaking wet cellar walls even after removing the cement render 8 months ago. Your advice on HRV systems was a eureka moment as I didn’t know they existed so many thanks for that! 👍

[@jeffhalbo96]

Excellent analysis of this issue, Charlie, thank you! Our experience of dehumidifiers totally bears out your endorsement of them, especially for laundry drying but also for general control of the RH in our home.

[@Sarhatabaot]

Perfect timing on this video. Just started looking into a mold problem we have in the room next to a shower.

[@CharlieDIYte]

Glad to hear it. Hope you find it useful!! 👍

[@reeshdelareesh6406]

Thank you so much for this. I live in an old Art Deco apartment with single glazed windows, no extractor. This really helped, I’ve bought a dehumidifier and noted the lifestyle suggestions. Great work ✊🏽

[@Kottesque]

Enlightening, especially about leaving the curtains open...I have a dehumidifier and always thought it was useless until this video and realised a couple of points, including the fact that we always dry the clothes in the same room...hence the high condensation. We are in the process of changing the windows to double glazing and I have found this video very informative...cheers!

[@lh3690]

Seriously one of the best videos on this topic I've seen. I'm new to being more humidity aware due to issues at our trailer. This explained things so clearly and to the point that I feel like I have a much better base from which to address our issues and less anxiety about unknowns.

[@CharlieDIYte]

So glad to hear that. I recommend getting a hygrometer, that way you know where you stand and what steps you need to take. 👍

[@tellylgeorge]

Great video Charlie. Very helpful and informative. I did all the same research a few years ago as I was having some issues with condensation and mould in my bungalow. I installed a good centrifugal fan in my bathroom and ducted my kitchen extractor to outside. But I also installed a PIV ( the one pictured in your video actually) and it has been great. My hygrometer rarely goes above 40 RH. I've set mine on a low fan speed which seems to change the air enough for my place and it certainly doesn't create a cold spot in my passage. When you put your hand up to the outlet you can feel the draft but this isn't enough to create a cold spot in the hallway. You can't feel any cold air when stood directly underneath the outlet. I haven't noticed any significant increase in my electricity bill from the fan in loft running constantly. When the loft temperature increases in the warmer weather the unit switches off as it is thermostatically controlled. All this said I really do think that your lifestyle habits are the main influence because you do have to manage the air inside your home as best you can. Keep up the great videos.

[@Gerry2210]

Excellent study Charlie, watched it before but never really took heed of it, coming into winter now, it made a lot more sense to me. Thanks for the work you put in, enjoy your channel.

[@davidpriest5253]

Morning Charlie, great informative video as usual. I have had the Kaarcher for years and it is great, but better still is the ebac (one of the older type), which is portable enough to cart around our small house. We use our tiny conservatory as a drying room, as it benefits from plumbed in central heating. The ebac makes the drying time very quick, and stops the obvious influx of damp air into the house (this seems to work better than using our washer dryer for drying clothes). Our house was built in 1906, and so is single skinned. As it is also small, we could not internally insulate as you have demonstrated. Where possible I move the furniture around and clean any mould patches with a mild detergent, which seems to keep the problem down. However, we have moved wardrobes that have been in the same position for ages, and uncovered disaster areas!. Thanks for making these videos, as they are extremely useful (off to open my velux window ventilation, which I normally have closed in winter :-).

[@JamesScholes]

Thank you for this video. I finally decided to take action on your advice and to stop breathing altogether. Breathing has been the root-cause of many of the problems in my life anyway. For example, I stubbed my toe the other week and afterwards it dawned on me if I wasn’t breathing this would have never happened to me. I’m also getting tired of inflating my lungs only to deflate ‘em a few seconds later (I mean seriously, who’ve got time for that?). Anyway, your video was the final nudge I needed to take action and I’ll be sure to credit you and your video regardless the outcome. Thanks again.

[@CharlieDIYte]

James, James you need to START BREATHING AGAIN 😬 Very drole but I hope you found the video useful.

[@annaartesana2622]

Funny

[@alexonfilm]

I'm right there with you. F'ing hilarious.

[@thequaintandquirky]

Love this 🤣

[@janettemajo2205]

Hilarious don't stop breathing please😁😂

[@geoffaries]

Hi Charlie another of you excellent videos, I've been involved in heating and ventilation for more years than I care to remember, but have seldom seen the issues so well explained, it is so good that I've sent your link to the company who manage my rental properties :-) I've been giving this type of advice for some years, but not so well as you have done. There is a caveat, which concerns the optimum level of humidity, I suffer from a form of bronchitis in the winter and have found that the best humidity for me is circa 55%, my doctor suggested putting the damp washing in the bedroom! but being an engineer I elected to use a humidifier where I can accuratley control the humidity. I have found that modern well insulated properties can have humidities in the 30 - 40% range, which dries out the mucous membranes inside of humans, more serious than chapped lips! I have also been involved with the design and installation of MHVR systems and one of the problems is in maintaining them e.g. people don't clean/replace the filters regualarly and they can introduce low %RH air into the house which will reduce the house humidity. I use the Meaco in my "man cave" where my toys live, because it seems that most of the refrigerant types are not very efficient below ambient air temp. of 15 Deg.C.

[@mikes6844]

Very detailed and impressive information about condensation and mould. Ventilation, ventilation, ventilation is my mantra Charlie and yet a lot of people don’t seem to adequately ventilate their homes. I see walls running with water, no extraction and wet clothes hanging on radiators just making matters worse. The popularity of open showers doesn’t help unless extraction is done at source and left until the room is dry. One of the best and cheapest prevention methods is the use of a squeegee . Fantastic vid thanks for posting, I will be sharing with my sons . 👍🏻👍🏻👍🏻

[@heriothandyman3148]

Well done on going the extra mile, fantastic data collection and analysis. We moved into a property with a Heat recovery system, not knowing anything about it. 2 years on, very very thankful for it.

[@rpcrev]

Very timely video. Thanks for that, so insightful. And my contribution to the discussion is- We have just had a positive air pressure system fitted to the loft by our landlord. We had terrible damp problems despite doing many of the measures you outlined. So in conclusion 1) It did work. Noticeable fresher cleaner air and less damp and mould in corner bedroom. 2) sadly our smart meter has gone crazy. Maxing out in the red almost everyday compared to sometimes being under budget.. . 4 kW heater is clearly the culprit. 3) Our hallway is never particularly warm but I would say it feels a little cooler. But not substantially. So it's doing a great job but at a very noticeable cost due to the heater. Obviously, years down the line will involve servicing issues too.

[@davidiand7]

Excellent video Charlie well done! I’m a Brit living in Sweden, all houses here built in the last 50 years or more have some form of ventilation system, be it natural draught ventilation pipes from kitchens and bathrooms, fans in the roof drawing air out of the house 24/7 (my current house has this, it works well, some windows still have the original paint and the house was built in 77). I have lived in a house with a heat exchanger, this would be my system of choice, I have known it to be down to -15 outside in the house +22 and the radiator was hardly on, you could hold your hand on it without it burning. (Heat systems are a little different here but that’s another subject). People do not use heavy curtains here, they are normally not drawn, they are light weight net curtains and for decoration purposes. Usually Venetian blinds are installed between the glass pains in the case of triple glazing older style, or you can have triple glazed window with an envelope with a vacuum and an envelope with argon gas which are great, sometimes they have condensation on the outside and when it really snows, it can lay against the glass for days without melting, I currently have both types installed all windows have ventilators built into the frame which you can control, I never have condensation. Having said this in this part of Sweden the RH is lower than the U.K. which is surrounded by seas. When it is a minus temperature outside the RH can drop dramatically I have seen the RH as low as 20% which is not so comfortable, at the moment I have 45% and it’s -3c outside. I have an alarm system which has smoke detectors with temperature and humidity sensors, even when I am not home I can see the humidity and temperatures in the house on my phone. As you say condensation can destroy your home but more importantly your health! Incidentally the main heating system I have is a warm air pump, they are a like an air on unit but push out warm air, it circulates the air round the house and can be used in the summer for cooling but it’s expensive to do that, I do have it on when it is hot sometimes. Sorry this sitt is in Swedish but you can translate using Google www.bast-i-test.se/tester_pa_basta/luftvarmepumpar.html

[@markallen8097]

Excellent vid as always. So happy to listen to someone who understands the connection to relative humidity, temp and dew point. So many "professionals" really don't understand and give people the wrong advice

[@CharlieDIYte]

Thanks Mark 👍

[@GosforthHandyman]

Charlie - that's some serious work you've put in to that video! Awesome stuff! Fantastic video as usual. We're in a new build at the mo. and the total lack of any form of damp or condensation has been a nice change. In fact we sometimes get condensation on the outside of windows! Wouldn't surprise me in the rel. humidity was

[@chrispybus8741]

£

[@DustyFingersRC]

Great video. I have watched many on this subject and this one was the best.

[@h9rae]

I suffered from damp and condensation in one room downstairs ,this i found out was due to no fresh air getting into the room/ fitted 2 vents at floor level direct to the outside and one at the top, problem solved no damp no condensation , the trouble is people seal up everything to stop draught a big mistake /good video very informative

[@wunwun8875]

This video is the best I've seen. Covering every aspect and every plan of action in a way thats easy to understand. Appreciate it.

[@CharlieDIYte]

You're welcome 👍

[@alanyoung7532]

A very interesting, thorough, informative and easily to understand insight into condensation and its causes in the home. A must-view for anyone wishing to understand and act on this issue.

[@surreyarborist]

This bloke is talking a lot of sense here now subscribed

[@frederickwood9116]

Nice work. I have obsessed about Relative Humidity values for a number of years. It’s not something that people find easy to understand. So explaining it is not always successful. I think you got it down nicely. Personally I think every house in our climate should have a dehumidifier but the concept is not widely understood. I have not played with many brands but I am a Meaco fan. I have bought both desiccant and compressor versions. My research found compressor ones seem to operate best around room temperature and the desiccant ones are best in colder spaces (15 c down to -10 or so) The desiccant ones tend to warm a room slightly which may be an advantage in some situations and can explain the extra running cost. I highly recommend a dehumidifier as a clothes drying solution in our UK / Ireland climate. You get good results for less cost than running a tumble dryer (I have seen bills drop significantly) as well as rooms/houses being healthier. The best drying results being where a largeish desk fan is also used to move air through the clothes rack even just at a slow speed. Also your don’t need to use the clothes drying setting but it will day things faster. I like the compressor dehumidifier you have there. Nice controls. I may have to try it out if I need to get another one some day. Thanks again. I’ll be sharing this when the topic comes up.

[@phil955i]

Very informative & interesting video. And I thought I was OCD about damp in the house! Lol. When I bought the current house 5 years ago I noticed that the drawers on our bare wooden bedroom furniture would get stuck in the Winter due to absorbing moisture from the air & swelling up. I've been running a dessicant type dehumidifier downstairs during the Winter months for the last 4 years & it cured that, as well as reducing window condensation. I also run a small Peltier type one upstairs, I know they're not very efficient but every little helps. A constant 50% RH is maintained & I have no qualms about drying washing in the house two or three times a week now, whereas I did before. The house temperature never gets below 15 deg. C (the heating's only on when we're home & we both work) & I now realise that I'm paying unnecessarily for the extra power that the dessicant type uses, next time I'll buy a compressor type when the dessicant one expires. I have noticed a marked increase in electricity bills since buying the dessicant dehumidifier, no surprise when it consumes about 250 watts on the lowest of the two power settings. I would add that the dessicant ones put a gentle amount of background heat into the room & when we close the door in the living room where it's situated it means the heating hardly comes on at all, as the central heating thermostat is in the same room.

[@tomcarroll2622]

Great Video Charlie, thanks. I live in Ireland in a 1970s bungalow. We have problems with high RH and damp. I was frustrated after installing a triple glazed window that even then I was getting condensation on the inside glass! The same with all my double glazed windows. I am about to install a Drimaster PIV. I also need to take steps such as reduce the moisture from the kitchen and bathroom. I am using a De Longhi dehumidifier which works great when drying clothes etc. The more I learn and understand the less problems I am having with mold and damp!

[@tomthumb2062]

Fantastic Video Charlie, we all have problems with damp/mold.. Well researched and explained. Thank you my friend 🙏🏻

[@CharlieDIYte]

You're very welcome - thanks for the comment, I really appreciate it!

[@deftouch]

This was a fantastic video Charlie, and so informative and interesting that I wouldn't have minded if it went on another 25 minutes. Love your videos, thanks a million.

[@CharlieDIYte]

Thanks David, I really appreciate that, and it's quite timely as I'm working on a smart heating install right now and in spite of my best efforts it's 23 minutes long already with another 5 minutes to go...

[@Viewer765]

@@CharlieDIYte how long did smart mode on your dehumidifier run for the first time before it started shutting off mine seems to run constantly and when do you have your running for

[@lawrenceslatter-buesnel1755]

Thank you so much for your videos. I watched both your videos on this and it’s really helped. We have changed our lifestyle habits to reduce excess condensation in the house as well as at night running a dehumidifier because we suffered with lots of condensation on our wall and windows. Massive change from 86% down to 50/60%. Thanks so much Charlie.

[@nbramson35]

Amazing advice just what I needed. Just moved into a cottage built in 1840s and having the same issues now winter is here, will be following your suggestions for sure!

[@CharlieDIYte]

Thanks Nathaniel. Bottom line, PIVs are probably the most effective solution but just being aware of how much moisture we generate and taking steps to reduce it are half the battle. 👍

[@mikebarber458]

Hello !! I've been a Master HVAC contractor for 30+ years and I really liked you explanation of dew point and RH . I have many clients in a high rise condo building in a very mixed climate of Richmond va. Floor to ceiling glass walls on one or more sides. The windows are double pane but the framing is aluminum. I've been dealing with the frames condensating for years. Dehumidifiers as you said solve most of the problem, but coupled with air flow from floor fans and or ceiling fans solved the rest of the issues. Combined they totally eliminated condensating. I've automated some Dehumidifiers to work in conjunction with the air handlers fan. I got excellent results

[@corvoattano9303]

Hello. From reading your comment am I correct in assuming that high airflow around areas where condensate builds up helps to mix it back into the room air which can then be removed using a dehumidifier?

[@libertyman3729]

Thanks for all the information it has been very helpful in understanding how and why condensation works in a structure and how to combat it .

[@christiea772]

The effort and detail that went into this video is much appreciated

[@geoffgeach6804]

I have recently had an Air Intake and Extraction system installed by Envirovent of Harrogate which draws air in through the Back wall of my flat and out through the front running constantly. The increase to my electricity bill is negligible but the difference in the flat is ABSOLUTELY FANBLOODYTASTIC!! I can not praise Envirovent enough.

[@markkendall6854]

Another vote here for PIV, a landlord of an end terraced old house with no cavity I the walls, spent a couple of grand fitting insulated plasterboard on the inside of external walls. Even lent the tenants a quality dehumidifier, but only fitting the Nuaire PIV solved the problem. It cost me a good tenant too, trying actively to resolve the problem. Property is now condensation free. This will be my go to solution 1st step in future.

[@BarnzyHQ]

Did your insulated plasterboard become wet ? Or was that dry before you fitted the PIV

[@howaboutanotherdave]

Brilliant, comprehensive and informative. This is going to be a great help to us. Thank you Charlie!

[@st3giftsusedtobest3jewelle36]

Fantastic video, thanks. We have had an ebac for about 20 years now, best thing we ever did 😀

[@Joelk2666]

Recently installed a drimaster after having condensation and mould issues. It has made the hallway colder but has cured my condensation issues

[@MurrayC]

Me too, the version without the heater. It makes the hall a little colder but that's no real hassle. RH is 50% with 90%+ outside RH.

[@matthewharding89]

We have a 170 year old terrace cottage. Modern render, windows and plaster. We tried everything. Even without changing our habits with the shower, cooking, boiling the kettle and drying clothes, we installed a PIV unit and the results have been dramatic. We've gone from up to 80%RH to

[@nigeld8694]

Great video Charlie. I always love your level of detail, reasoning, explanation and research that you do. Keep up the great work!

[@CharlieDIYte]

Thanks, I really appreciate that. Thank YOU for watching my vids, and for the comment. It's a big motivation receiving positive feedback 👊

[@declanpboles]

The best presenter I seen in a while and knows his stuff. Well done.

[@ModerateDev]

Great video, well informed and really impressed with the effort you went through collecting your own data. I myself have bad damp in the house and have recently bought a great de-humidifier that has brought the humidity levels from over 60% to 40% I am yet to see if this will help the damp on my walls and ceilings but I am hopeful. I found the section on windows especially interesting as even though I have double glazing I get a lot of condensation. I have decoded to buy venetian blinds so that I can open them during the night while still remaining relatively private and possibly pointing a fan at the windows to help circulate the air. I have also found paint on Amazon claiming to help resisting damp build up that seems to have good reviews. Once again great video thumbs up from me.

[@andmath08]

Got an update on your damp? Would be great to know if the dehumidifier helped you 👍

[@lukeferguson9010]

@@andmath08 the ebac dehumidifier has definitely helped in our house

[@speedfinder1]

I've had a PIV system like the one you show, since 2010. It inputs into the central hall directly above the water radiator. It has vastly improved the moisture problems in my 1930s solid brick house. I still have other systems in place, but it is a good percentage of the solution to my damp issues in the winter.

[@thepaintedsock]

Hi. I had one installed recently. It made no improvement to humidity after a week. Have you actually measured yours? Before and after?

[@speedfinder1]

@@thepaintedsock Sorry, I didn't do any Before and After recorded tests. I just know that the damp smell in my house went away after a while with the PIV system running continuously over about a 6 month period. There is a chance that you may have to be patient to see any measurable improvement as the humidity content in the atmosphere in your home may be being kept high by residual humidity in your soft furnishings, or in fact the buildings structure. "Air Conditioning" of any type does take a while to show any real results unless it is working inside a sealed water tight box. This isn't a cop out answer but in my modest experience, these things tend to need either to work in conjunction with a refrigerant or dessicant electric dehumidifier for faster results. Good luck! 👍👍.

[@mosmes02]

@@thepaintedsock if you don't have anywhere for the "stale" air to go, you won't see a difference, you need ventilation such as weep vents or air bricks.

[@Noor-kp1yb]

Does the filter need changing ours isn’t working as it was before the bathroom is drenched after showers and even just washing hair over the bathtub!

[@paulfletcher7227]

I had a PIV installed a few days ago, and there no has been no condensation on my windows since

[@GHSme34]

Thanks Charlie; we have had all similar issues in our very basic and old French cottage; and your explanations and analysis make so much sense, We already have a dehumidifier (compressor type) and now we are considering purchasing another one as they do work exceptionally well to keep damp away ! Thank you.

[@CharlieDIYte]

Thanks Glyn. If you can, get a PIV installed. It will be the most effective solution. Nuaire or Vent Axia.

[@brianconnolly3267]

That was an incredibly comprehensive video. You taught me a lot about specific details and over-arching ideas in a relatively short time. Thank you very much.

[@CharlieDIYte]

You're very welcome Brian. Thanks for the comment 👊

[@virtualgeezer]

Amazing effort!!! Perfect timing as well, as I was in the process of trying to reduce our humidity in our old victorian house down from around 70% to stop black mold build-up. Thinking of testing out the Blue Maestro Tempo hygrometers, as they can keep track daily, hourly etc and send it all to your phone. Nice work Charlie!

[@alanedwards9069]

Moved into a circa 1900 mid terrace stone house 3.5 years ago, had major issues with condensation for around 18 months until I installed a PIV. Stopped it dead. Within 2 days I put away the window vac and it’s been there for the last 2 years. Installed over the staircase and the only time you feel cold air is when walking up the final flight of stairs (three storey house). House went from 80%+ humidity to between 40-50% virtually overnight

[@philipoakley5498]

what size was it & was it costly? (even if in retrospect it was the best pounds spent ;-)

[@ohmydog9]

Your videos have been so helpful and have taught me how to master the humidity and mould problem in my flat. We are very careful about controlling humidity like keeping the bathroom door closed - I’m always yelling at people to close the door! We are also lucky to have a window in the bathroom. Have opened all our trickle vents and automated a dehumidifier to run each night. When I see the RH sneak above 60% I open the window, even if it’s freezing, if only to ventilate for 15/30 minutes. No problems this winter! Thanks so much. Your videos on this topic are the best I found.

[@brettstanton247]

This is one of the best videos explaining the very complicated subject of condensation. Spot on mate

[@CharlieDIYte]

Thanks Brett!

[@DennisMcDermott]

I fitted a PIV unit a couple of years ago in my bungalow, this was in January, the next morning I had no condensation, and have not had any since. It does not make the area where it is installed cold, brilliant system.

[@simonmccutcheon7085]

Hi, which system did you have? I am looking at one by envirovent

[@geoffwoollen]

@@simonmccutcheon7085 Dont buy a PIV as Dennis- it just wastes heat and creates cold spots. Get a MVHR as per video. eg, Nuaire An easy DIY install in the loft and extract the damp air from the bathrooms, whilst inputting fresh air heated by the extracted air. Picked up mine from Ebay.for £200

[@TK42138]

Quite possibly the best condensation advice video on KZbin.

[@CharlieDIYte]

Thanks 🙏👍🏻

[@GurungyNoHamuster]

Some Meaco observations. We got the one you show ages ago and used it in the laundry room to good effect through the whole house. When we first dehumidified there was humidity in books, upholstery, carpets, etc. which declined to normal over a couple of weeks. The Meaco started leaking in cold weather after a few years so it was relegated to a garage. A second Meaco dessicant (same model) did exactly the same (be aware they are impossible to open). We now have a Meaco compressor (same size) which is by far the best. We track energy use quite closely and none of them were significant, and all did a great job with humidity.

[@aj1finch]

Awesome video, @Charlie! Really comprehensive. I think we'll be doing some of the things you suggest.

[@bucklesmagee3806]

Living in an older property I never knew like a cave it traps the moisture well. Thanks for this 👍👍

[@tapeslayersreviewsreviews9807]

Can you tell if the walls are lime plastered or cement or gypsum

[@Chriswales]

Great video, confirmed most of the things I've found living in an older house. It had a mix of window types and damp/condensation problems after we moved in. Like you we tried those little damp traps and a small dehumidify both as you said completely useless. We now have a large compressor dehumidify that's used to dry clothes in a small unity room. We don't use it in main house now because there isn't any need for it. Still get some condensation on windows we haven't replaced/upgraded but like you we use the window vac to help control it. As you said there's no one solution and you need to understand the whole problem. Then you can fix what you can and manage what you can't. Nice tip on clearing the water from the shower, think I'll also be making that a rule in our house.

[@mayhemuk88]

Removing the wife n kids helped alot especially when they have a bath/shower, ooh too cold to open the window, great video and well explained

[@jonschofield4280]

Excellent stuff Charlie. I've watched so many videos regards insulation and condensation issues and your's is the first one that makes any sense whatsoever. You explain it in a straightforward easy to understand way and it makes so much sense, Great stuff. My go to reference point from now on.

[@CharlieDIYte]

Thanks Jon, I really appreciate that. I did a quick update video recently if you have a moment. Goes over much of the same ground kzbin.info/www/bejne/hJPXmp1-gN5ljNE 👊

[@GrandslamTim1]

brilliant timing charlie! I am experiencing condensation and mildew issues. you are a natural teacher for explaining things well done. PIV looks very interesting. thank you sooo much Tim

[@taforth]

Very explanative and detailed review of this subject - thanks! I have a new build cottage with in-floor hydronic heating throughout. This heating system is considered amongst the most efficient available, but one of the drawbacks is that because the heating ‘element’ (ie 3” concrete floor in this case) is relatively cool (when compared to forced air furnace, or radiators, etc.), humidity is not reduced in the winter. So, even though I have relatively efficient double-glazed windows throughout (u value < 0.3), I’m experiencing a lot of condensation toward the bottom of the windows. It is resulting in the fir interior window frame getting damaged (triple coat Varathane wood stain peeling off, along with black mould accumulating on some of the North facing windows). Temperatures in the winter (cottage locate 2 hrs north of Toronto) are typically in the range of -5 to -25C overnight. I have installed both a whole home coil type dehumidifier, as well as an HRV. Unfortunately, due to the heavy structure of the building (large roof overhangs and cantilevered floor structure), I was only able to plumb it through walls directly adjacent to the utility room (ie limiting circulation). I would like to suggest that you recommend extraction fans/hoods/etc. with caution, because if you do not provide a means to provide ‘make-up’ air, you will create a net low pressure in the building, thereby drawing outside air into your building, wherever your weakest seals are, which will exacerbate your condensation issues in the winter 😬!

[@grahamarnold2591]

One of your best video's I think, thanks for the heads up, I sometime drone on talking about one of my pet topics "Interstitial Condensation".You manage for 24 mins to keep my attention, very informative and well presented. Many Thanks.

[@CharlieDIYte]

Thanks Graham - I really appreciate that!!

[@tiggywinkle1000]

Learned a lot of useful tips from your video. Thank you. I do not have room for an electric clothes dryer, and use one of the old-fashioned 'Sheila-Maid' airers that wind down from the ceiling on pulleys. I found that more moisture was always deposited on the windows as a result. To counter it, I now set the washer to 800 RPM spin, to stop excessive machine vibration. Then at the end of this normal wash cycle, leave the clothes, etc. in the machine and set to a further 1400 RPM 'spin only' cycle. The washing comes out almost dry after this and the condensation on the windows practically eliminated.

[@kevinmccarthy8847]

Well done Charlie, it's having the time to do the investigation and numbers you've done over the winter months. You da man...much appreciated 👍

[@StuckInTheM1ddle]

Excellent video, full of obviously well researched info that you have to put a lot of time and effort into. Don’t worry about the length, I much prefer the complete story rather than you breaking it into small chunks. My wife thought I was mad when a dehumidifier arrived recently to deal with all of the indoor clothes drying being done but she’s now an evangelist after seeing how much water it removes and how much quicker the clothes dry. Keep up the great work that saves me endless hours having to go down a rabbit-hole myself on 😀

[@CharlieDIYte]

Thanks Mark - yes this was quite a brutal one to put together, about 175 video clips in my editing folder and I still missed a couple of things!! Wise move on the dehumidifier. Did you buy it because you were having mould problems?

[@StuckInTheM1ddle]

@@CharlieDIYte I wasn't haven't mould problems in the room it's in but we have been drying a lot of clothes in the room given the time of year and I wasn't happy with all that moisture going around. I actually bought several of the Thermopro's a while back and saw how high the humidiy was getting in the room where the clothes drying is so bit the bullet and bought one. I found the below website a great resource when researching on dehumidifers and condensation in general . The guy who runs it really goes deep on his research too. www.fixmyroof.co.uk/videos-and-guides/condensation-cure/best-dehumidifier/

[@opentrail]

You are a natural presenter, full of useful information. As you mentioned, many sources of moisture and different strategies required dependent on where in the house the moisture is coming from. I've also listened to Peter Wards KZbin channel and looked at some of the Vapourflow, based in the UK, equipment such as Autostat. I've been looking into this myself and have some questions and observations: 1. I was considering a PIR from the loft but found somewhere in the 1980's the yorkshire stone slates were turned, as they should be, and rather than fit a vapour barrier beneath them, the roofer fitted some form of total plastic barrier. Firstly worried that vapour cannot escape and secondly no point fitting a PIR no fresh air coming in.2. Absolutely agree with you about optimal humidity using outside and inside sensors and cannot understand why a lot of gadgets MVHR, PIR's etc don't use these - opportunity to start a new business. 3. I’ve also seen advertised electric friendly Natural Air vents that have a Vapour barrier also called passive dehumidifiers, not sure if these work or are cold in winter. 4. Newer condensing boilers have an optional external thermometer that a lot of plumbers don’t bother with and these can save you a fortune as they adjust the maximum heated temperature of water pumped to the radiators based on external and internal temperatures. I love my Intergas Eco boiler. 5. Secondary glazing, either outside or inside. Outside saves the paintwork but can't open windows, inside traps condensation. 6. Ceiling fans help move air around. 7. Paint Stormguard breathable water repellent onto the external water to help them keep dry but let water out.

[@eternallearner4753]

I installed a Nuaire Drimaster PIV unit three years ago. In winter, the area around the unit is a little cooler, and in summer, a little warmer. There were no extractor fans fitted in my renovated cottage (now remedied), and every morning all the windows had to be severely Karchered! Now I can't even remember where I stored the Karcher. My decision to install the PIV unit was also made as it is claimed they reduce radon in a building (the cottage is in Cornwall and its walls are granite). I put the drier rack in the smallest bedroom and dry the clothes very successfully with the help of the ebac dehumidifier (I have a tumble dryer, but not the bank account to support it!). Great video, amazing research. Subscribed!

[@CharlieDIYte]

Wow, you've totally nailed the problem and you're so wise to have a dehumidifier to deal with moisture from drying the clothes. I don't have major issues here with the RH levels at a pretty constant 45 to 50% but I'm so tempted to install a PIV just to keep things circulating and to minimise condensation on the remaining, single glazed windows, as the reviews on them here are unanimously positive. Out of interest, I'm guessing you still get congregation when you shut the curtains? Thanks so much for the comment and for subscribing 👍🏻

[@leeholke9851]

My job is a water damage and mould restoration. And u have done ur home work well done.

[@CharlieDIYte]

Thanks Lee - I really appreciate that and it's always good to hear positive feedback from a pro!

[@matthewgurd6477]

Great video, about two years ago we did similar research and decided on installing a nuaire PIV in the upstairs hallway. Humidity levels dropped in the problem room from +70% to 50-60%. We chose the heated PIR and did notice chilly air being pumped at the start so we do increase the heat in the winter. Electricity bills were not drastically impacted.

[@EssGeeSee]

I concur. Only run our PIV at night.

[@abutw0]

I have read that as moist airvin house, naturally rises to attic, there is a risk that that very same humid air can be pumped back into house. Similarly if attic is vented via eaves etc. Fresh air in Attic can also be very moist.... Any thoughts?

[@Coxy002605]

@@abutw0 Moisture naturally rises with warmer air to the ceiling, where it gets trapped. The fresh air coming in from outside is almost certainly of lower humidity than the air inside the house.

[@louispippie]

Getting into the science of this is great, as are your solutions. I scoffed when my wife bought a Karcher wiper but it's now an essential bit of kit for the shower. This and the "applying silicone to shower trays" Vid should be required viewing for trainee plumbers and building surveyors.

[@donna9497]

Donna C ? Where did you purchase Karcher Wiper. Advance thanks for video as well !

[@apache16789]

Great vid. Very interesting and instructive. Well done and thank you.

[@RichardNutman]

We had an Envirovent PIV installed. The house we moved into was extremely humid, loads of mould growing on the metal window frames, and in cold corners of bedrooms. It completely solved the problem 100%. The electric it uses is minimal, few pounds a year. It does warm the air if it's cold, but it also has the effect of pushing down the warm air from radiators that collect at the top of the stairs, so the net result is it doesn't cool the house. Totally silent and no condensation on windows at all. Washed jeans even dry inside in record time! :) Our downstairs is quite open plan, so the air coming in does circulate quite well. We got the control unit with it, and after the moisture level of the house was sorted, we just run it on trickle mode now, only turn it up if we're drying several loads of clothes in the same day.

[@CharlieDIYte]

Thanks for this Richard. I'm going to install one in time for the winter. Just mulling over which manufacturer to go for but I'm interested in what you say about the Envirovent. Was there any particular reason you went for this over the Nuaire or Vent Axia?

[@RichardNutman]

@@CharlieDIYte No particular reason, it was the 1st one I saw and didn't know there were others. The model they do now is newer than the one we have, but it's still working great. Just had the filter on it changed few months ago. It can feel a little draughty at times, as our main sitting area is below the stairs where it's located, which is why we insisted on having the remote to turn it down. Normally they set it to normal and you don't get the remote. But I think the new ones integrate with a smart phone app.

[@jackjones3657]

This fact of single pane windows being that much more susceptible to outdoor temperature fluctuations make perfect sense for causing condensation. It's time for me to get double or even triple pane windows! Good video, Thank You!

[@charlescp1558]

It’s a while since you posted this, but I thought I would say we installed an Envirovent in my daughter’s 2 bed flat and it solved damp and mould problem overnight. Can also dry clothes on airers very quickly. No loft, so mounted above entrance door and draws air in through a hole cut in acrylic we swapped the glass out for. Fantastic product, not cheap, but works and very low running costs, was teamed with their humidistat extractor serving bathroom and kitchen. Keep up the good content!

[@isyt1]

I live in a 1930s Scottish house and have gone through the same experiences and research as you have with similar results. Insulation and ventilation is key and we run our dehumidifier regularly, especially when cooking and drying clothes beside the wood burning stove. When showering we open windows at opposing sides of the house to flush out the moisture. Also important to fill any holes and cracks on the exterior walls that are letting water in.

[@CharlieDIYte]

Thanks - it's always good to hear enterprising solutions from people in a similar situation!

[@BoiledOctopus]

"Demystify" - I like it Charlie!

[@markbrown1412]

Hello, I live in interior Alaska. I am in the process of building and have the good fortune of being near the cold weather climate research center in Fairbanks. I must say, your video is spot on regarding this moisture/ventilation issue in the home. Understanding what the dew point really means cannot be Overemphasized. Your video covers these issues in a very helpful and informative way. I am a retired environmental chemist, have a good grasp of the subject matter, and have seen people insulate their homes in ways that contribute to this problem. Even though My education should make me an expert on the subject, it does not. I had to modify my home plans after consulting with the people at the cold weather research center in Fairbanks. My ideas about properly insulating my home were misguided. People get information from KZbin, their neighbors, and their friends, believing they are doing something good for their home, when in reality, they are actually making their moisture/ condensation worse. Why? Because they are getting bad/inaccurate information, and they don’t understand the concepts regarding air temperature, humidity, and dew point or relative humidity. Building practices that work in warm/hot climates probably will not work in a cold climate. I learned this upon moving to Alaska. Thank you for your well done And spot on video.

[@WisdomIsPrecious]

What specifically are the mistakes ppl make that you learned about?

[@gmmooseblaster]

Excellent, informative video. I'm pleased to see that some of the efforts I've been using have been confirmed by you.

[@NicMG]

I'm dealing with the mould issue in my flat, mainly round all the windows. Definitely given me some ideas to work with. Thanks bud.

[@CharlieDIYte]

You're welcome, Nick. Good luck sorting, and don't forget Nuaire do a PIV for flats as well.

[@johnrussell5245]

I fitted a heat recovery ventilation system in our barn conversion 18 years ago. It was the best money I ever spent. I've fitted it in other dwellings since and I'd go as far to say I'll never live in a house without MVHR again. It should be mandatory in all new builds. I've never come across a house that can't be retrofitted, with a bit of effort and the will to do it. They might cost (£4-6,000), but they're easy enough to fit by any competent DIYer. They should be a priority ahead of frivolous things like fancy cars and expensive holidays. They will improve every day of your life spent in your home.

[@rtaitm]

High praise, but how does it improve your life so much?

[@andrewstones2921]

John Russell is correct that MVHR is the answer, and having fitted it 18 years ago he was well ahead of the pack. I work with MVHR daily, but the company that work for now only install MHRV in new build houses. It's perfectly correct that with effort you can retrofit virtually any home, but to work at it's best the house should be airtight and insulated to a very high standard, and typically that's not practical in an older home. In the course of my work I have seen poorly installed MHRV by builders and well installed MHRV by DIY'er, but typically a retrofit has so many constraints on the type of ducting you can use and the optimal design layout that whilst very worthwhile and a huge benefit over not having it, it almost certainly will not approach the effectiveness achieved in a new build with an equally high standard of airtightness and insulation. The bottom line here is that all new homes SHOULD have MHRV and the cost is very low if installed at the right stage in the build.

[@dave2166]

@@rtaitm simply they continously extract the stall stagnant moisture laden air with fresh filtered and tempered air...whilst recovering upto 90% of the heat energy....24/7. They will be mandatory in new houses within 5 years id say if the government are truly serious about nett zero carbon aspirations

[@andyandy3506]

Fantastic video, thanks. I've had damp problems from time to time, and had dismissed the idea of bringing in more air from outdoors, as I'd assumed it would be too damp. Completely failed to consider that the lower temperature would reduce its capacity for moisture... A couple of things to add... a very good point about the water vapour from cooking, and I've found a good kitchen extractor fan to be well worth the money spent on it. Probably not worth worrying too much about the kettle though, as despite the noise and visible vapour, an average kettle will only lose a few grams of water when it boils. Insulated plasterboard can be a good way of topping up the overall insulation in a house, but ideally needs a thorough assessment to be undertaken before it's installed. The danger with this stuff is that you're moving the hot/cold boundary away from the surface, so it sits inside the wall itself. So any water in the air can end up condensing on the cold bricks behind the boards, which can be a disaster. Worst case is you get water penetrating from outside (can happen with older non-cavity houses) as well as water vapour coming in from the inside of a house, and this all ends up running down the wall behind the plasterboard. Anyway, thanks again for posting this excellent video. I will definitely be sharing it.

[@andrewhigdon8346]

Relative humidity is a very complex value to predict. Temperature is only part of the problem. For example, winter time can be just as high of relative humidity if not higher than summer time.

[@russelldunning294]

@@andrewhigdon8346 True, it can be raining outside but it can still be fine to open a window to let in the drier(!) air. Winter is the main problem due to cold temperatures leading to condensation and mould.

[@axers22]

Thanks for the video. I've got a PIV without the heating element. It does make the whole house a lot colder during winter. If curtains are closed and no trickle vents are installed then it does take a while to get rid of the condensation. I've put it on a smart plug and turn it on during the days the weather is dry and wet clothing is drying. It does indeed make clothing dry faster!

[@spencerwilton5831]

axers22 a good condenser dryer is far more sensible than drying clothes on racks when line drying isn't possible. People complain about the running costs, but the advantage of a condenser dryer is that they push heat into the room which partially offsets the heat required from your boiler.

[@davidedwards60]

Thank you Charlie! I am an Engineer although of the Software persuasion but I still naively thought I had a decent understanding of condensation. Having watched this video (which is perfectly pitched IMO) I am a lot less complacent and much happier that I now know better.

[@dudleyjoseph9485]

Great video. I'm another advocate for PIV. I've got an old house which had elevated humidity levels mainly we think due to a few original flagstone floors. Mainly solid walls with minimal or no insulation also. PIV has almost completely solved condensation problems. You do need to make sure however that the source of the air in the loft space is drier than within the house and to do this, you really need to be thinking about absolute humidity levels rather than relative. The best PIV units will measure absolute humidity and turn on and off as they need to. Generally, if your loft is reasonably ventilated from outside, you should be OK. Location of the PIV is also critical. Needs to be as central as possible. Some house layouts wont work. In addition, you may need to encourage the air movement through to the rooms that are further away from the unit possibly by installing additional passive vents. Definitely need to keep doors to rooms open and ensure that the PIV is not 'short circuited' by having any existing extractor fans close to it. Yes, the air coming out of the unit can be chilly and will cool your landing down but it doesn't seem to affect the rest of the house. You would not want a unit dumping air directly into a habitable room. Go and take a look at Pete Ward's channel for a wealth of stuff about humidity in older houses and absolute vs relative discussion although he doesn't appear to be a massive fan of PIV.

[@afnankhokhar5578]

Thank you for such a detailed response. Very helpful

[@steffananthonyholden2752]

Also trim your doors 10mm from the FFL to allow free flow of air movement

[@gortagnan]

@@steffananthonyholden2752 Thanks ..makes sense but just to be sure ..FFL meaning F (?) floor level ?

[@JuiceBanger1]

final floor level. ie after you have laid the tile or lino etc. i discovered this term when installing a bath and bath panel. it just means leave a gap or shave the door to get a gap@@gortagnan

[@stevesmith3395]

I have had a Nuaire PIV HC unit installed and running for over a year. I can say that it absolutely transformed our excessive moisture and condensation problem within hours. I wish I had purchased the heat element one but understand they still dont warm the air up enough. I experimented a little and have found that setting three is guaranteed to stop the moisture build up and stop mould growing. This does chill the air locally somewhat when temperatures drop. Setting 2 seems to be a happy medium where you barely notice a chill and it keeps moisture down. I tried setting one but in winter you will see a small amount of condensation return in perhaps a bedroom furthest from the unit. So I an now sticking with setting 2 and will introduce a bit of ventilation to the bedroom door. I need to do a bit of work to improve the insulation around cold spots at the edges of the upstairs ceilings. I initially changed the loft insulation as excessive insulation without sufficient ventilation causes this in a lot of older houses. Just a bit of tweaking to get the balance right. This PIV unit has been vastly superior than the dehumidifier that I still have as its effects are very localised. I cant recommend a PIV unit enough and they are cheap to run. So much better for my health. I developed asthma since moving to this house. The mould used to keep appearing but does not anymore. We used to get it in wardrobes and cupboards, even downstairs there would be furry growth on boots and handbags. It was truly awful but it has been eradicated and only my sons bedroom got tiny mould spots after I experimented by leaving the unit on the lowest setting. In summer it may cut out due to high temperature. Dont worry if the temp drops again and it doesnt come on. It can be four hours or something before it comes back to life after too high a temperature.

[@baldeepgill7916]

We have a nuaire in our rental and a envirovent Mr venty in our home and going to buy a nuaire in a new rental we have acquired as it has a bad case of condensation.

[@limitless1692]

This 20 min video ... It just gave me a lifetime of experience ... Thank You Very Much Sir !!

[@CharlieDIYte]

You're very welcome. Thanks for the comment 🙏

[@foopai]

Awesome video Charlie! Thanks for an easy to understand and near perfect explanation of RH.

[@markandfionastilwell2323]

Installed PIV units 6-7 years ago and our condensation problems disappeared. No issue with cold draughts or temperature. Our house is circa 1900 stone with slate roof and double glazing. Have had several family and friends install them and all have been really impressed with the difference.

[@CharlieDIYte]

Thanks Mark, yes, there's universal love for PIVs in this comments feed. I think I'll be installing one next winter (too many videos in the pipeline to do it now!)

[@brownesugar1000]

Sounds great how much did this cost please?

[@andrewadam4989]

I've added Positive Vent systems to two of my houses and find they work very well. There is certainly a chilly spot directly underneath but I don't find that it makes the general house spacer cooler or cause me to have high heating to compensate. I used to have a dehumidifier and find that the PV system works much much better.

[@rossmanning4863]

Andrew Adam I’ve got one with a heater on it. Does the job.

[@dave2166]

Its the perception of air movement which makes you feel its colder... a fan on a hot day when its 30c will make you feel cooler even though the air passing over your skin is still 30c

[@prizecowproductionspresent4463]

As a semi retired Glazier that worked in England for 3 years i understand the problems you get in your houses. Like Mr Cooke i found this explantion on how to deal with Humidity and air flows to be spot on. The fact that i bought a house that was built nearly 70 years ago has given me the understanding of solving such issues as is always the case when old details meet new lifestyles. Once again you have proved that youtube is a wonderful research tool if you take time to find the relevant information. Aussie Jeff

[@CharlieDIYte]

Good to hear from you Aussie Jeff! I appreciate that. There's a lot of love in this comment feed for the Nuaire or Vent Axia PIVs. Totally eradicates condensation. Can you get something similar in Oz?

[@gillian417]

Not obvious. So helpful. I've spoken to several tradesman who've never offered this advice. THANK YOU and now a subscriber.

[@CharlieDIYte]

Thanks Gillian. I did an update video a few weeks ago kzbin.info/www/bejne/hJPXmp1-gN5ljNE I appreciate the sub 👍

[@Largeone1968]

Another vote for PIV. I’m a landlord and the go to solution for lifestyle damp is a PIV. Go on any landlord page and you’ll see the same answer time and time again. In the six years that I’ve been fitting them, the Nuaire have gone from £260 to just shy of £400 for the heated unit. This is no doubt due to popularity. They just work. They’re absolutely silent unlike dehumidifiers. They’re much cheaper to run than dehumidifiers too. What’s not been mentioned is they help allergy sufferers by the filtered air driving out pollen, dust and mites. I’ve had to block up certain air vents close to the Piv due to air taking the path of least resistance. Highly recommended

[@truth952]

Where do you install them? I think a PIV would be a solution to one of my rental properties which has significant damp in cellar to the point it’s recently been affecting corners in living room. Am I best to put PIV in the cellar by air brick or put it in loft ?

[@baldeepgill7916]

I completely agree we had a bad cause of condensation in our rental property and our tenants complained alot. Then, eight years ago I came across PIVs and I got a nuaire installed and I must say it has worked 100% and I also have a mr venty envirovent installed installed in ours too. Now, we have acquired a new property.. We have noticed the internal glazing is soaked in water. Will be investing in a piv here too before we get tenants in. Prevention is better than the cure. A nuaire got installed yesterday and checked it out. boy is it a bit noisy..hope it settles down. Going to ensure that within the tenancy agreement the tenants are not allowed to meddle with it.

[@dave2166]

@@truth952 they mostly go in a loft for a house... however not every house suits a piv...most do. The only true way to understand its suitability then a free survey from someone like envirovent will tell you all you need

[@andrewriley4204]

I've fitted one. Think of a PIV like the car windscreen demister. That blows air over the windscreen (basically a window) & provides a clear view without Condensation. Problem is, we add heat to the blower in cars, simply for our comfort, who wants to sit there freezing? Equally the standard NuAire PIV is a cold blown air so stairwells will be cold unless, you add the bolt-on heater or start with the model with a heat unit Cheers, Andrew

[@dave2166]

@@andrewriley4204 they should not be folded without the heater.... my company doesn't. Even though the top of the ceiling above the stairs will be the warmest air in the house youre redistributing that air and shifting it elsewhere.

[@fabmanly1070]

I you have an attic, you can install a Positive Pressure Ventilation system. How many of you run your Bathroom fan 10-15 minutes after you’ve finished? Probably very few (you need to completely cycle through an entire room of air). PPV system is like having a tube running into your house from the roof. Imagine putting a large super hose into this and pouring water down it rapidly, your house would start filling up and eventually water would find its way out through the cracks in your windows/doors as its under pressure. That’s what a Positive Pressure air system does. It will work its way through the house forcing out stale damp air. Your house needs that change of air constantly to avoid stale stagnant air. Its called cycling, and you need to work out your volume of interior living space so you can install the correctly powered system that will cycle the correct amount/volume of air for your home. Your furniture/ clothes/ lounge suite/ mattresses (can hold anything up 10 litres of water-water! Wow imagine sleeping in a bed with 10 litres of water in it!) must be purged of this moisture before you will be healthy. So the system will take a few months before you truly have a healthy home, but you will notice it after a few days with the firs at signs (no weeping on the windows). Leave cupboard doors and any spaces with closed doors ajar so air can flow. Its all about air movement and pressure.

[@markwilliams5654]

most Fans have a built in timer or humidistat

[@JayL123]

@fabmanly1070 Would we need Trickle vents on the windows for PIVs to work? None of the rooms have ventilation holes in the wall but have trickle vents in the windows. We plan to change the windows and I wonder if I have to get tricke vents in it for the air to flow. Apologies if its a silly question, but the trickle vents are all dusty and mouldy.

[@fabmanly1070]

@@JayL123 Had to look up trickle vents. We don’t have them in New Zealand. Air, like water will always find the easiest exit point. We never had any of that in my homes with PPV’s. Talk to an installer near you. We also have two positions for our handles to be positioned on our windows, so they can be left ajar if needed, but still locked. Air will always find a way out. New windows are good and bad. Good to seal, but bad because they are so good at sealing up. But as you say, you have these extra vents that sit hove your windows.

[@stevemain9582]

Wow! probably the best concise information I have come across about condensation, well done sir many thanks

[@DecoD71]

Absolutely the best video on KZbin about damp/mould.. I've been using a dehumidifier for past year it's great. But recently bought a condenser dryer and drying cloths is definitely best buy for us

[@TT-zf1bn]

Which one did you buy ?

[@DecoD71]

@@TT-zf1bn the dryer? Just a cheap one in did.

[@RichardsModellingAdventures]

We have a PIV unit in our bungalow. It fixed the problems we had with damp over night. No problems with cold air at all. We just run it very slow

[@DerekHundik]

piv whats that ?

[@bmatic2069]

@@DerekHundik Google PIV Ventilation - loads of information!!!