DIY install of Lindab MVHR system: Why, what and how

[@maryhaddock9145]

Exactly what I need to know. Looking forward to watching next vid 👍

[@JurassicJungle]

Hi Mary. i really need to film a follow up as this as been in and running for quite a while. I am waiting for the final commissioning as the guy doing it wants me to finish the final bathroom before he does that. We are very happy with MVHR, we have had no issues with condensation or potential mould that the original property had. If you have any specific questions do get in touch,

[@maryhaddock9145]

@JurassicJungle Many thanks for that. What concerns me is the airtightness and how effective the mvhr is if it's not perfect. My build is a timber frame, clad in SIPS with masonry on a large part of the ground floor. So I am also concerned about condensation occurring within cold bridging within the insulation.

[@JurassicJungle]

@@maryhaddock9145 As you may have seen our build was an extension (we left almost nothing of the old house behind) so we have not had to test with blowers etc. We started this project trying to exceed what was asked for with building regs and tried to make it as air tight as was practical. We have a mix of construction with the few old walls having a 50mm cavity and the new parts 150mm. We have flat warm roof, and old style cold roof areas. Our original building had just about zero ventilation, no trickle vents, no bathroom vents etc. We have damp and mould all over the place. Our driver for MVHR was to have good air quality and humidity across the house. 2 of our 3 bathrooms have no windows so good ventilation was very important. I later read of possible issues with lack of air tightness, I can see there is potential for the lower air pressure in some rooms to allow cold air to be pulled in th the house. Our house is still not really finished, the old cold roof insulation is nothing like complete, we removed all the old fibre glass and are installing 300mm of non itch insulation. So far I have only installed 100mm across about 60% of the roof. My view is that our MVHR is working very well and we are very happy. We would have had to install 5 separate vents so still expensive. What is your alternative to MVHR? I assume you would have to fit several extractors that just blow your warm air outside and would be less effective against your cold bridging risks. The one thing I would do differnetly is locate the MVHR unit somewhere that it is much easier to get to. We have a low pitched roof and wanted to keep it away from bedrooms etc. Not the loft is finished and the pipes are all in it is going to be very tricky to change the filters and service the unit so I can see I will probably relocate it to the centre of the loft close to the hatch. If I could I would have installed it in a utility room.

[@d.beaumont9157]

Very helpful video. It would be interesting to see how you access the flat roof areas.

[@JurassicJungle]

Hi, I will see if I have any photos as it was tricky. That only needed to go to 2 rooms and in both cases we could run the pipes the the end of the joist and down between a pair so avoided having to cut any holes.

[@smellypunks]

Very interesting, would be good to see how you insulate the pipes. Also you might want to get a light for filming in dark rooms.

[@JurassicJungle]

Thanks, i will film adding insulation. I have realised my camera had a manual iso setting which I have now set to auto.

[@samosa111]

Love you videos. Wishing you all the best with your project. Would love to see more videos about your loxone system

[@JurassicJungle]

Hi, thanks for the feedback. I will be including more on Loxone as it is commissioned and what does and does not work as we hope. It’s going to be about 2 months as the cabinets are on a long lead time.

[@OffgridinSouthWalesUK-yw5gl]

New subscriber here. What a really useful video on MVHR. This is one area that we’ll definitely be looking at doing ourselves. The National Self Build Centre is an amazing source of quality information with easy to work with suppliers👍 Thank you. Can I ask what the internal height of your extension living room (pitched roof room) is please. That large sliding door and top window really make that aspect👏

[@JurassicJungle]

Hi there, glad you found it useful, did you see the update I posted yesterday? I will also show the commisioning process in a few weeks once that is done by Terry at heat recovery south. The pitched roof is about 3.6m, we were limited by the low pitch of the original house that it joins to. I would ideally have had a higher pitch and looked at a warm roof construction but we simply did not have the space for that. We are very happy with our MVHR setup combined with UFH, the place just feels so comfortable and we don't get any condensation. The old roof is not yet fully insulated so I reserve judgement on overall running costs but think it is inline with what gas would have cost. If you do look at ASHP I would 100% go for a big battery, we run most of the time on low rate energy and we are heavy users with an EV and lots of washing and drying from a holiday rental business.

[@OffgridinSouthWalesUK-yw5gl]

@ Thank you, yes I have watched that too. We’re planning a ‘caravan act’ structure where the internal height has to be no more than 3.05m. Hence my question. I won’t take your time up now, but would like to pick this up again once we progress. There are so many areas that you have touched on during your build, and I’d like to expand on some. Thanks for your swift response and just to add, what you’ve achieved to date is outstanding. Best wishes Paul

[@JurassicJungle]

@@OffgridinSouthWalesUK-yw5gl Please feel free to reach out. I have had phone and video calls with quite a few people about our project and questions they have with theirs. We have learnt so much doing this project it would be great to help others have a smoother journey.

[@OffgridinSouthWalesUK-yw5gl]

@ Thank you, very much appreciated 👌

[@peterwalton1502]

Very useful. Thank you 👏👏👏

[@JurassicJungle]

You are welcome 😊

[@willdashwood82]

Really helpful video, thanks for posting. I'm hoping to install a MVHR system in my early 1800s solid stone walled property that I'm completely renovating and hope to do at least some of the work myself to save money. Was it only the issue of not having trickle vents in windows that mandated having to get it signed off for building regs? Also thanks for the heads up on the nsbrc. I might make the long drive down for the next show. Cheers

[@JurassicJungle]

Hi, yes for a renovation I think if I asked for no trickle vents it needed sign off. Even if you didn’t need to do that I think getting it commissioned probably is essential. We have now almost finished the install so will add a short update video. It is not too difficult to install but think hard about where you will site the heat exchanger. We would have to cut a hole in the ceiling to replace ours I think but installing in the garage would have made ducts longer and more complex and added fire risk addition parts. I would recommend going to Swindon on a show weekend, there is one in a couple of weeks. I have read they mvhr may not be such a good idea in a very leaky property. I assume the positive pressure could force more warm our out through gaps.

[@bntambridge]

Another interesting video! Sorry, don't know your name. It made me think about the differences between MVHR and HVAC. You have a heat pump and underfloor heating but of course you need ventilation, which this provides without the heat loss (as you explained). HVAC systems provide cooling, heating and dehumidifying but less efficiently than MVHR. 2 questions. 1). If heat rises why are the inlets in the ceiling, would it be optimally better in the floor/wall if you could get the tubing there? I guess it wouldn't be balanced in the room (compared to the advantage of being in the center of the ceiling). 2) With global warming and hotter summers (even in England) how efficient is the cool air transfer compared with an HVAC system? You hope that the insulation will keep the heat outside?

[@JurassicJungle]

Hi Bryan, Its Ian ;-). I think it is certainly possible to put the vents at floor level, indeed Robin Clevett @ukconstruction did this in his pool house. If you have not looked at his channel I would recommend it as it is excellent. Installing underfloor or in the walls would be much harder and certanly not possible as a retro fit. Our bunglaow actually had a hot air heating system originally with ducting under a suspended floor, we removed all of that. The vents don't actually go in the centre of the room, they are placed away from the door and ideally not over a place your would sit or lay in bed due to the risk of cool air you may not want. The idea is to ensure air is moved around the house. As we make houses more airtight this is important. MVHR is NOT an AC system, the airflow is quite low so it certainly wouldn't reduce temperatures anyling like an AC system but I understand it can help a little. Our home is mostly North facing so we should not get too much solar gain, we should be super insulated so hoping the place is cool in summer. It is possible to add a preheater which is a small radiator into the MVHR inlet to reduce the risk of cold air in the winter. The MVHR unit shuts down below certain temperatures to reduce this risk, I think it still expells air but doesn't bring it back in. As you has seen we are living in a half built house so wont know until this summer and next winter how all of this is going to work. In particular the heat pump. We have been using £30 a day of electricity some days but that inculdes charging a car and heating the caravan. The last few days with the caravan heating off it has been more like £6.

[@DatumCAD]

Just the overview I needed but with plenty of facts and figures which others omit, so thank you. 🙏 We are looking at a very similar system for 1990’s 200m2 bungalow and had a quote for 3.2k for VentAxia Kinetic Plus B unit (with 200m of 75mm pipe work, manifolds etc just like yours.) so this would seem pretty decent. Company is BPC Ventilation as they supply to both the UK and is here in ROI. Looking to wall mount the main unit in the utility room as had worried it would be hard to access and maintain in the loft despite plenty of room for it up there as we have a larger pitch than yours. To gauge cost & for size comparison could you let me know what model your unit is please?

[@JurassicJungle]

Hi, it is a the same unit that you are looking at, the kinetic plus B. I had a quote from. BPC and they were a little cheaper, probably almost identical to yours. I didn’t go as far as having the design done with BPC. I went with Lindab and Heat Recovery South based on the support and ability for them to come and commission for my building regs. I think the BPC pipe work is broadly similar to Lindab.

[@DatumCAD]

Thanks for this, helped confirm things for us and did decide to go with BPC in the end as will be full self install and don’t require building regs sign off etc. like yourself. Everything arrived within 2 days of ordering and they supplied a layout drawing and full commission info / flow rates. So far so good, looking forward to see if it solves our mould issues and generally improves the air quality and heat losses. Thanks again for your video and help on this 🙏

[@JurassicJungle]

Thanks, Good to hear that, I am sure you will have fun installing it. We have now completed most of the secondary pipework which is much easier than the rigid steel sections. We have also started installing all of the insulation. We are hoping it makes a significant difference as the original building (very little of it remains) had terrible problems with damp and mould, we think pretty much all related to very limited ventialtion.@@DatumCAD

[@johngregory5280]

@@DatumCAD Hi, I just watched this video and read the comments as we are also looking at a similar system for our bungalow. Just curious to know what your thoughts are on BPC now that you've probably got everything up and running. Many thanks!

[@DatumCAD]

@@johngregory5280 based on our experience I can easily recommend them for anyone looking to carry out their own installation (or at least source their own components for the same). The drawings and upfront service we received really decent, and the prices were the lowest of all our enquires. We had one cowl with missing clips that they sent out FOC soon after reporting but several weeks after delivery, so customer service was good in that regard also. The only minor issue we had, was a little confusion/conflicting information (from their end) when we wanted to dig deeper into the calculations that they provided, and once we were ready to self commission. After a lot of to-and-fro I ended up doing a deep dive into the regs & calculation methods, before making my own spreadsheet to determine our best operating flow rates. So I would say, if you are willing to do some upfront specification etc. of your own system requirements and then allow them to do their calculations in isolation, it will give you some confidence you are getting the right solution for your home.

[@radfoo]

Interesting. How do you control the system? Will it just monitor humidity or also look at co2 levels? Thanks.

[@JurassicJungle]

The current switches only monitor humidity but it would be very easy to add co2 as well. It’s just a bit of logic in Loxone after that. Loxone do offer a C02 sensor.

[@xxxx-wv6hp]

Could you tell me why this vent axi is bringing smelly nasty air inside my apartment?

[@JurassicJungle]

Sorry not sure, is it an mvhr system? If so it’s important that the incoming vent is not close to a soil vent pipe of other source of bad air as it can bring that back into the house. It can filter the air to remove dust but not odours.

[@xxxx-wv6hp]

Yea it’s an VENT-AXIA MODEL SENTINEL KINETIC 443219 by 220-240 50HZ 150W INTWRNAL FUSE 2.0A. I live in a high floor apartment so is there a possibility of I am being contaminated by poisonous air or having nasty air plugged to enter through the vent inside my apartment?

[@xxxx-wv6hp]

Hi could I stop air from coming in, just turn off the machine and glue the grills for my safety? I don’t think they will do a thing and I don’t wanna end up poisoned by whatever is entering those vents so better just seal it, so maybe silicone would prevent any air from the grills or would you recommend something else?