Hot Water VS Cold Water Humidifier Efficiency Test.

[@sNEAKYnIGHTmUPPET]

Great video, never thought oof testing it in this way before. As an HVAC instructor I must say that your test is very original. There is one thing that I believe that you are incorrect on. You seem to be under the belief that water MUST drain to somehow clean/clear the pad; This is in fact not the case. The reason they have a drain is that it is more simple of a design to not have to worry about it and just dump it down the drain. I have confirmed this with the engineers also. as the water evaporates, the scale is left behind. Running more hard water over will not clear the pad which is why it requires an annual replacement. You should be just fine in throttling that needle valve back until no water comes out the drain at all. The other approach that manufactures are trying these days is called "Pulsed Valve control" They use a temp sensing timer that is mounted to the supply air and waits until it warms up. then it turns the water on for 4 seconds and then off for 30 and repeats until humidistat is satisfied. I wanted to be sure of what I was quoting in this post so I pulled an Generalaire GF-3200PFT from our inventory and examined the timer. It is called a "HSA 055" and it is installed before the valve and controls this water saving pulsing. I assume that the idea is to put enough water on to wet the pad, then 30 seconds to evaporate then repeat. I hope the weather hasn't been too harsh on you this year on your side of the Rockies, over here in BC we have had a few doozies! One last thing that you mentioned was that we do MOST of our humidifying in the winter. We in fact do ALL of it in the winter, and NONE in the warmer months. Is is technically ONLY when heating. When AC is running it is actually dehumidifying so you will want to make sure that your humidifier is turned off during the fairer weather months. Cheers from Vernon BC

[@tomiyourtradesguy6708]

As a gas tech I have always know that humidifier with hot water to it will get home to higher R/H%. I have never came across data or study to show. This is a fantastic VIDEO and i appreciate your time and knowledge sharing it with us. I'm planning to make a video on how to install a humidifier and will link your video to as reference for Hot vs Cold water for humidifier. Thanks buddy! fantastic work!. 😎✔👍

[@UtmostOutdoors]

Thanks! I appreciate your comment. Hard to tell sometimes if anyone else out there finds these tests useful or interesting!

[@tomiyourtradesguy6708]

@@UtmostOutdoors well people do.. I found this video when I was looking for information.. now I'm enjoying watching your other content on gold stuff.. great attention to detail 🙂 A+

[@-.__.__.-Rad]

@@UtmostOutdoors Keep up the good work! I had the same train of thought, but I didn't find the patience to test - thanks

[@Justin-nl9no]

Awesome video and I thank you for taking the time to make it, in your cost analysis you forgot the electricity cost reduction for not running the fan for 8 hrs making using hot water even cheaper!

[@farcow]

I didnt think I was going to watch to completion when I first saw the 20minutes. But the engineer in me greatly appreciated this analysis! Well done!

[@UtmostOutdoors]

I'm glad you found it this interesting. I had never seen an analysis like this done before, and my own curiosity got the best of me. It's nice to see others are curious as well!

[@possiblybhavin]

ditto! I didn't think I'd watch the whole video. Great video!

[@chrisgray5518]

Funny, I was right in the middle of asking why not reduce inflow to match absorption rate so that the least amount of water drains out, and as I was asking you answered my question! All very helpful information, but I think that little valve at the end is most valuable. I will be adding that when I set mine up. Thank you!

[@Watch4Me]

What answer did you get? Should I try to limit water?

[@chrisgray5518]

@@Watch4Me I have not yet gotten an answer from the HVAC company about adding the valve. They are coming this week to look and I plan on asking them.

[@dankuntz8611]

Outstanding! I am considering adding a whole-house unit and was interested in hot/cold effiency and water usage. You nailed it! Thanks!!!

[@UtmostOutdoors]

Glad it was helpful!

[@Drmehul75]

Great video , thanks for scientifically and mathematically explaining various permutations combinations.

[@UtmostOutdoors]

Thank you, and thanks for watching!

[@DaveDugdaleColorado]

Wow this was great, I was thinking of doing this myself but you took it to a new level of detail. Now I don't have to create this video test since you did it already. I measured my water usage too and I was shocked. I love the idea at the end, I will try this trick. I will try to half the water usage after my solenoid. After I try this I will report back here to give my results.

[@UtmostOutdoors]

Awesome! I'm glad the video was useful and look forward to hearing back how it worked out for you!

[@modernwize]

i used to watch your canon vs nikon videos

[@TravThompson]

The Needle Valve was an instant purchase for me, i was using my shutoff valve to attempt to regulate the flow, the valve would leak and also not get the flow that low, thanks for this video!!

[@mattz4962]

Thank you for taking the time to do the water temp comparison and the cost analysis. Cheers!

[@UtmostOutdoors]

My pleasure, thanks for watching!

[@JamesCarlson-uf8xl]

Amazing detailed and well thought thru analysis. Thank you for sharing and posting this! Also congrats on IM Penticton.

[@highwind8124]

Nerding out on the calculation of what it costs to heat the water. I paused at 13:13. I guess the efficiency rating of the hot water tank means what percentage of the heat content of the fuel will be used to heat the water versus the heat the escapes out of the vent pipe. Some watts used to run the fan on the vent motor, but its the heat content of the air used for combustion that's not factored in. Because you use indoor air for combustion for the burners in the hot water tank, cold air from outside comes back in to replace it which the furnace then has to heat up. There are "direct vent" hot water tanks, but tanklesses are direct vent and they condense. But then I don't know if a tankless going on and off so many times during every call for humidity is an issue. I've never tried it.

[@j3dwin]

I'm replacing an ancient humidifier in my house that hasn't been connected for decades. This has been very helpful. As an engineer myself, I was impressed with the methodology here.

[@UtmostOutdoors]

Thank you! I'm glad the video was helpful!

[@Birndogger]

Great video!! I was wondering these exact things. Very helpful.

[@chrisspanyer1525]

Great video. I would love to see a follow up of how much water you were able to get into air after cutting water supply in half. As that would reduce the heat so I would assume less humidity. Thanks for your time and attention to detail

[@UtmostOutdoors]

That's a great point about less flow meaning less heat, I imagine it would land somewhere in between the hot and cold for water into the house, while still putting much less down the drain. Maybe I'll test and update here in the comments.

[@tiavittitoe9536]

@@UtmostOutdoors Great video! I love data. I have the same curiosity as Chris, so if you get to that analysis, I'd also pop back in to see the results. Thanks again for spending the time to do this video - it's been super helpful, as I'm literally about to install my new whole house humidifier, and now I know exactly how I want to run my supply. Cheers!!

[@SeanLynchXY]

Hooray, science at home saving money, water and just having fun! 5 gold stars and a smiley face :)

[@mpxz999]

Thank you for making this video! Also a Calgarian here I recently installed a couple devices to measure the radon levels in my home, and as a consequence, I discovered not only that I am super high on radon, but also that my house is a pretty steady 20% humidity both in my basement and upstairs. No wonder my hands are always so dry that i cant even use the fingerprint sensor on my phone the past few weeks lol I'm going to try installing what you have setup here too. It looks like it worked wonderfully. Thanks again!

[@UtmostOutdoors]

Thanks! A little humidity can go a long way as far as keeping your skin happy during the winter! And good luck on the radon issues.

[@rickkrieger4455]

Thanks for all of your work. I have a needle value on the cold water side so I'm hoping that I can just shut it down and then crack it open an archive the same result. Thanks again, you did a great job and provide a great service.

[@davidsabia203]

I'm curently a HVAC tech , And I installed a lot of these humidifiers . I problem i come across is the water valves fail's or cloges . I've used in the past ,I've used a Refrigerator water filter ,and installed it in line before the Humidifier . it seam's to help .

[@mattwag11]

I personally prefer a cold water hook up with a bypass style mounted on the return air as I have mine set up to only run with a call for heat. I've always adjusted my valve so that the water just trickles out of the overflow tube (helps to install a clear tube for visibility). One more thing: I much prefer the sharkbite fittings when dealing with 1/4 copper which is what most humidifiers/ice makers will be connected to...can't stand 1/4" copper compression fittings, they seem to be very prone to leaking. The plastic 1/4" sharkbite quarter turn valve is a blessing too. I only use copper line as it has natural antiviral properties that pex or poly doesn't...especially when it comes to an icemaker!

[@UtmostOutdoors]

Great info, thanks.

[@SteveBoyer10]

Wow this is why I love the Internet. Thanks for your scientific approach! Did you notice any change in effective relative humidity increase after reducing the flow? Thanks!

[@UtmostOutdoors]

Thanks for the kind words! This video was not doing well at first, but now seeing how it is helpful to people like you makes me want to do more like it in the future! I have noticed no drop in performance with the reduced flow. There is still excess flow to drain plenty of water down the drain and keep the pad fully wet. I haven't even noticed any faster build up of calcium deposits. Seems like a total win win!

[@andrzejkosson4655]

Great video! If you don't have a motorized damper on fresh air intake running furnace fan all the time will also be bringing dry outside air into the house, effectively drying up the inside air. I completely agree with using hot water for humidifier but will left furnace fan cycling with the burner.

[@michaelbuono9826]

Nice test scenario you set up. Never thought of the energy exchange between water and air. That makes me feel better... I'll be hooking up to the hot water line tonight!

[@PickledAndFermented]

Thank you, im just shopping for a humidifier, and this is a huge help.

[@UtmostOutdoors]

Glad it was helpful!

[@dankuntz8611]

Have you considered adding a catch tank to recycle the excess water? Hate seeing all that water go down the drain - water is getting expensive. (And scarce in some areas.)

[@UtmostOutdoors]

I thought about it, but figured it would end up just being too much work to be worth it in my area. After adding the needle valve to slow the water loss a fair bit, I'm much happier with the efficiency. Plus, the water is pumped from the river where I live then goes back down the drain into the same river a bit downstream, so it's more a financial thing that a water waste issue to me. I've gone after the low hanging fruit so to speak and taking things further doesn't seem worth it right now where I live. Thanks for the question though! We definitely both though the same thing.

[@toddtrautman7734]

Thank you sir for doing all the things I didn't want to do but wanted to know. Very thorough.

[@squashgolfguru]

Fantastic!!! I'm also in Calgary...and have done exactly the same thing. The savings in water/heat isn't the issue...it's battling the Alberta dryness which is why this is such a good method. Using less water to achieve good home humidity is always worth the change.

[@classicalconcerto6742]

This is exactly what I am looking ... Excellent work bro!

[@jmaus2k]

You answered my question if hot water helped and indeed it does. Thanks. An easier option is to get a reduced orifice. It's just a little plastic piece with a hole that is inside the tube by the valve. They have different options for flow rates. The extra valve is a good option too, just a little more work.

[@RoombaRepair]

I was trying to determine how much water is used by the Aprilaire 500MX unit I purchased on Amazon. Before I switch to using drum type humidifier, I find your post. Thank you for your detailed results of your test . BTW, I am also from Calgary. I am going to finish to install my Aprilaire 500MX instead of using a drum type humidifier.

[@UtmostOutdoors]

I'm glad the information in this video was helpful for you! Enjoy your low maintenance humidity!

[@GrowingAnswers]

I had never considered this. I also use a 1/4 turn off my hot water feed for it with the same type of humidifier block. I was wonder though why not just turn down the 1/4 turn valve to reduce flow rate? I assume it’s to be able to freely turn the feed on/off without having to recalibrate each time?

[@UtmostOutdoors]

The size of orifice that the water goes through to feed the humidifier is pretty small, so a 1/4 turn valve is very hard to adjust low enough to make a difference without just shutting off the flow entirely. Even the little needle valve is a bit touchy when it comes to adjusting down the flow. If you can get your 1/4 turn valve to slow the flow a bit, then that should do the trick, I just found that it was nearly impossible to find the sweet spot between fully off, and more than needed.

[@iamhives]

What a great video. I have just moved into a new house and have an Aprilaire 700 humidifier (the grid style) which is hooked up to the hot water line. However, an added complexity in my setup is that my hot water is from an on-demand water heater (no tank). Initially I was worried that the humidifier would fire up the water heater but it looks like the humidifier flow is below the low flow threshold so while the humidified is hooked up to 'hot water' I guess its effectively only getting cold. So I don't think I really have the option for the maximum evaporation of using hot water. I'm currently running the humidifier in the mode where it will run without heat if needed to raise the humidity but may turn that off and see if it can keep up with the humidity demand using heated air only. I guess where you live makes a difference. I'm in Virginia so not ultra dry (I don't think). I guess the economics somewhat depend on the ratio of water cost to heating fuel cost (gas, propane, oil electric, whatever). Also, for those of us who have water softeners the cost of salt and the water to soften probably needs to be taken into account also. I like the needle vale idea and may something similar on my copper water line.

[@UtmostOutdoors]

Thanks! Cool to know those on demand units have a low flow setting that keeps them from turning on for a Drip. At least now you know a little more of the efficiency you get with each setting and won't need to wonder! Best of luck!

[@jko0526]

I am considering installing a whole house humidifier and was wondering if it would affect my tankless water heater. Thanks for the info.

[@iamhives]

@@jko0526 my experience. Is that the on demand heater does not turn on when the humidifier is running. According to the manual there is a 'low flow threshold' for the water heater (Rinnai) I think of 0.3 gpm. So in my case the on demand heater does not fire up just for the humidifier. In my mind thi sis good since it would seem to be a waste of gas for such a small trickle but it does mean the humidifier doesn't get hot water despite being hooked to the hot line (maybe the water will have residual heat is the water heater recently rain for another demand). This probably depends on your make/model of on demand water heater but I suspect all would have a low flow threshold.

[@jko0526]

I also have the Rinnai model so mine must have the same low flow bypass. I was thinking about having the model 800 steam unit install just to get the hot water from the unit itself. Still investigating which one if any would be the right choice for my home.

[@228dlb]

if your wanting maximum evaporation may want to look into a 110v 1.5 gal hot water tank that goes underneath sinks, I have the same issue in my house and I'm looking for a more effective solution to add humidity to my house

[@rexhavoc5643]

What about the rate of deposition of mineral build-up on the pad with different water temps? I don't know how hard your water is, but hard water is a factor in some areas that use flow-thru humidifiers.

[@UtmostOutdoors]

That's a good question, I will update in the comments if I notice a difference in a few months.

[@drdez]

@@UtmostOutdoors update?

[@TK-setophaga]

Good job explaining! Does restricting the water supply bother the solenoid?

[@UtmostOutdoors]

The solenoid doesn't mind. It's just an on/off switch for the flow.

[@davidstevens1911]

I use a Merv 12 16x25x4. Thanks for the suggestion. I will try that next winter.

[@clif1969]

Love the last part you did will try that on mines. Have 500m manual

[@UtmostOutdoors]

Yeah, that last trick worked great! I checked in on it today and it's still running great, no issues with the reduced flow.

[@coniccinoc]

Getting ready to install my new Aprillaire whole house humidifier. The instructions recommend using a hot water feed.

[@UtmostOutdoors]

Good to know. I've stuck to the hot water feed with mine running a reduced flow rate with the needle valve. Seems to be performing well!

[@coniccinoc]

@@UtmostOutdoors One thing weird tho. I bought the manufacturer's install kit. It has a plastic 1/4 feed tube yet the instructions for the humidifier says to connect it to hot water and do not use plastic feed with hot water. I am returning the kit and using a copper feed tube.

[@shanew7361]

So hot water is better and don't use to much supply because it's literally being wasted down the drain? I'm having a new furnace, power bypass humidifier, air Purifier and led uv light installed on Saturday. Shoukd I have them connect it to my hot water supply and what size tubing/brass line and type of valve?

[@UtmostOutdoors]

I've left mine connected to the hot water, It seems to humidify better and use less water. The supply line usually comes with the humidifier, they should know how to hook it up.

[@R0cketRed]

Thank you for this very informative and helpful video, you did a really good job with the test only thing I'd fix is using the American measurements instead of the everywhere else much better and makes actual sense measurements lol

[@UtmostOutdoors]

Freedom units! 😉

[@cardinal.oconnor]

Thank you for this excellent cost & energy analysis. My guess is you’re an engineer - takes one to know one 😂

[@kgk4569]

Great video. Other considerations: - higher efficiency in evaporation (hot/hot) will keep up with humidity demand of leaky older houses. - when using a tank water heater the water will have less sediment, leading to longer pad life. - cloth pads vs aluminum + clay pads will have different efficiency. - lastly, the final consideration should not be just $, it should be money as compared to comfort.

[@UtmostOutdoors]

Well said!

[@paulhelstrom840]

Thanks for doing this... just one comment on belt type humidifiers: they are unhealthy because you are keeping non-sterile water in a stagnant pool then rotating a dirty non-sterile belt through that water then blowing non-sterile room air over the belt evaporating that bacteria-laden water into your living space; think Legionnaires disease. The water panel humidifier type has a constant supply of fresh water and does not use or retain pooled stagnant water; unused water runs to drain. I have a graduate degree in Microbiology.

[@KT-hx2ul]

What happens when regulating the inflow of water to wet the pad but minimal water flows out and is wasted. Does bacteria then grow in the pad as if it were the stagnant water in a tray?

[@joec8651]

I have my whole house humidifier supplied by my hot water, but it clogs every day from sediment from my hot water heater. Municipal water is also very hard, so may just look into a water softener before swapping out the supply line from hot water to cold. Very frustrating.

[@UtmostOutdoors]

I wonder if an inline sediment filter would work for you. They come in various sizes, but if you searched for "whole house sediment filter" on amazon or your local hardware store I'm sure you would find something that could help.

[@johnterpack3940]

You could plumb both hot and cold then just wire a separate solenoid for each that was triggered by either hot or cold air. That way the cold water would help the AC by pulling heat down the drain.

[@proxlamuz4591]

Excellent video. Btw where did you get those folding wall panels?

[@UtmostOutdoors]

Thanks! I got the wall panels here: unclewiener.com/product/new-4-panel-folding-wood-room-divider-privacy-decor-ws180/

[@Qbranch1024]

Very helpful, thank you!

[@mbeck2113]

Great job. Thank you for the video Question :why don't you turn the supply vavle that you already had (the 90°) to lower the flow of water instead of adding another clamp valve?

[@UtmostOutdoors]

Thanks for the question. A 90 degree valve does not allow as fine of adjustments as the needle valve does.

[@mjmason75]

Excellent video and general analysis. Thanks!

[@UtmostOutdoors]

Much appreciated!

[@davidstevens1911]

I’m not sure I trust the accuracy of your data but I appreciate your willingness to do the research. My similar system is set up to only run when the furnace is heating. Right now I’m more concerned about the degradation of air quality due to all the dust created by the minerals in the water being blown into the airstream.

[@UtmostOutdoors]

If you are concerned about particulates in the air, you can always upgrade you furnace filter. The bypass humidifiers will run all the humidified air through that filter prior to it entering your homes circulation. I run a 4 inch thick MERV16 filter that had enough surface area to prevent any excessive backpressure you might find by running a filter that fine in a thinner profile. Just some food for thought.

[@rcgillsympaticoca]

​@@UtmostOutdoorsThat's not how mine is configured. I just had a SECOND humidifier added today, this one with hot water. They both take off air from the return before the filter and it goes back in after the heating. I guess I figured that's what bypass meant. I was a bit ticked because the first one used to work with just the fan running if I told my ecobee it was a steam type rather than evaporative. Now they've changed them to only work with heat cycle. How am I supposed to get any additional humidity in the many months of the year when we don't need heat on? New house, just in two years now. All the engineered hardwood had split in the first year. Ottawa.

[@jwhite4]

@@rcgillsympaticoca Regardless of if the humidifer is installed on the supply or return side, the air always goes from the pressurized hot size, to the less-pressurized return side. So the humifiied air is always entering the return side. As long as that is before your air filter, the humidified air will always run thru the filter. For the concern about, "the minerals in the water being blown into the airstream", as someone else mentioned, you can add a refrigerator-type water filter (or other inline water filter) between the water supply line and the humidifier. Though you might need to make sure it's rated for filtering hot water.

[@clutteredchicagogarage2720]

Thanks for the video. I've been frustrated by the amount of waste water that seems to run through my humidifier. In my case, my humidifiers are not in the same rooms as my hot water heaters. The original installers hooked the humidifiers up to cold water supply lines, even though the installation instructions specify that they should be hooked up to hot water supply. In my case, there are no hot-water supply pipes in the utility closets where the furnaces are located. I would have to open up walls and run additional hot water pipes to my utility closet with the furnace, which I don't want to do. I think what I'm going to do is either buy or build what's essentially a radiator, install it against the hot-air ducts coming out of the furnace, and run the water supply through that. I think that if I slow down the flow rate, I'll be able to heat up the water before it flows into humidifier solenoid so it's warmer when it flows over the evaporator pad, which should result in a higher evaporation rate. If I build a heat exchanger, I'm basically going to get some 1/4 flexible copper tubing, use a tubing bender, and effectively try to maximize the length of tubing that is running on the supply side, placing it directly up against the hot-air duct. I'm also going to swap out the orifice on the supply side of the solenoid to one with a lower GPM flow rate. I think that even if I can raise the water temperature by 10 to 15 degrees celsius and slow down the flow rate, I can increase the evaporation rate. Your experiments helped me validate my assumptions and decide that this might be worth my time. In any case, I don't think I'll make it any worse. I just have to buy a coil of maybe 50 feet of 1/4-in OD soft copper tubing for $50. I'll figure out the bending radius of my tubing bender, do a little math, and create what's effectively a crude heat-exchanger to warm up the water before it flows into the solenoid.

[@UtmostOutdoors]

I wonder if simply slowing down your flow rate with a needle valve would be enough so that you would get a boost in efficiency without requiring any further modifications. It would be the place to start at least. Best up luck with the project!

[@tomference4618]

Thanks for sharing,..I would have liked to know was if using a hot water feed may cause more mineral build up on your evaporator pad.

[@UtmostOutdoors]

Thanks for watching! It's been a year since I made the switch to hot water supply and the pad looks no worse than a year running cold water. I thought that flowing less water over the pad might increase deposits, but it seems I still have enough to flush the excess minerals down the drain. The hot water coming from your hot water tank technically has no more minerals in it than the cold water. In fact, since minerals tent to build up in hot water tanks over time, that would actually mean the water exiting the tank has less minerals in it that what went in. (it's the same cold water going into the hot water tank, so if it leaves minerals behind then there must be less in the water exiting... probably an imperceptible amount, but still...) Either way, I change out the humidifier pad yearly and that still seems to be enough.

[@jwhite4]

@@UtmostOutdoors That is a good point. Hot water is stored in a tank, where theoretically minerals and other undesirables can settle in it (it's why flushing the hot water heater annually is recommended). In contrast, the cold water line is always "live".

[@Spinonemaster]

Nice video ... I have been using hot water for my bypass humidifiers for decades (US/Mid Atlantic) I'm a builder ... it's quite logical that hot/warm water will evaporate much quicker in the system ... down side is without moderating flow rate you will waste a lot of hot water ($$) ... I prefer using a ball valve located close to unit so I can adjust flow to a minimum, just enough to wet pad ... also , insulating that hot water supply line helps as it's calling for water (will lose heat from supply on down time) also, I'm now in a house using deep well water and it's very cold ... the whole point of humidifying air is comfort and more efficiency of heating that air ... down side is hard water will eventually slow the water flow down too much so it must be checked throughout the heating season ... normal set up in eastern US is humidifier runs only with heat/blower running ... if you use a evac pump for excess, reducing water flow saves wear and tear on that pump ($100/plus)

[@UtmostOutdoors]

Well said, thanks for sharing.

[@Theferg1]

Great video and info. Let me ask you something, sir I live in the southern states in North Carolina. Would it be better to go with a cold water? Thanks

[@UtmostOutdoors]

I'm no expert, I just did an efficiency test. Either way will be fine, and if you use a needle valve to control the flow a bit like I show in the end of the video, you will save some water. If you find you don't get enough humidity out of the setup, then you can change to hot water, which will put more humidity into your home.

[@jwhite4]

I would say now. If you want to put humidity into your air, hotter water will always be more efficient at doing it.

[@nkhockey09]

Hey, more of an automotive tech than I am an HVAC tech lol. Putting in a new system and I have something bugging me. Has anyone ran a cold water line supply with a filter to remove mineral build up.... but then run a coil of copper line around the vented heat pipe, etc from the furnace to use it as a "heat exchanger" ? Logically that creates a meet in the middle kind of situation where I can control both sediment and temp. The only other option I can think of is to plumb the lines for the water line and cool down the hot water temp slightly to where I'm not pushing the upper limits of the filters? Curious to see if others have messed with this to deal with hard water and running " warm water " to it?

[@UtmostOutdoors]

To my knowledge, most water filters will not reduce sediment in your tap water. The minerals are dissolved as ions and pass through filters unchanged. I think to reduce sediment from water you would want a reverse osmosis water filter. but I'm not sure that would be worth it. One thing I noticed was that after switching to hot water, my humidifier filters seem to last longer... I think the reason for this is that the total hours of runtime has been reduced since the humidifier works more efficiently now it does not need to run as often to keep the house at the set level. Another thing to consider is that the water exiting your hot water tank would technically have slightly less total dissolved solids than in the water entering the tank. Otherwise where would the scale build up inside the tank come from? Running DIY heat exchangers and stuff like that to extract maximum energy from your furnace may or may not make sense from a "return on investment" standpoint, but so long as you are not causing any potential harm with your experiments, and don't get yourself into any trouble with building codes or safety, then I don't see the harm in a little DIY efficiency project! Best of luck my friend! Note: In an area where water use is extremely restricted, the drum style humidifier puts 100% of the water into the air from a tray with a float switch. In that case using reverse osmosis filtered water may actually be worth it to reduce maintenance intervals... I have no personal experience with doing this though.

[@Morticia713]

Great information! I am curious if the humidifier can be connected to a tankless water heater and work and be more efficient? Anyone know? Thanks!

[@UtmostOutdoors]

I think if the tankless system is forced to cycle on and off a lot for just a slow drip of water, it may not be great for the efficiency of the heater... I'm not fully versed on thankless heaters, but you would definitely need to do your research and factor that into the decision. Sorry I don't really know the answer on this one.

[@toddtrautman7734]

I believe I read somewhere in AprilAire's FAQs that tankless water heaters have a minimum flow rate before they start to heat. These won't meet the minimum flow rate, so it won't fire up just for the humidifier.

[@Nihlistpunk_CM]

Okay so you save money on water, and granted it's pretty efficient, however now you gotta make sure you have soft water going to it and purified so you don't breath in calcium and whatever crud the water heater is pushing out and letting it collect, so now you have filters/salt, basically more maintenance. Which some people have that stuff already installed

[@davem5175]

Did you add the needle valve upstream or downstream of the solenoid valve? Or doesn't it really matter?

[@UtmostOutdoors]

I don't think it would matter for flow rate, but I plumbed it in before it gets to the humidifier solenoid, because that was the easiest place to access the line.

[@davem5175]

Thanks. That's where I'll put it for the same reason. Mine will be on a copper line.

[@davem5175]

Added a needle valve and found that the valve needs to be almost completely closed to reduce the flow from 200ml/minute full open to 100ml/minute. Not sure yet if at 100ml/minute if the water panel is getting saturated evenly (good saturation) or is it short circuiting down the middle because of the reduced flow. My other concern is will the needle valve plug up much more easily because it's barely open. Time will tell.

[@UtmostOutdoors]

Good observations. I also found the needle valve was a bit touchy and difficult to set at a trickle. For my humidifier, the water distribution still worked great at the lower flow, and nothing has plugged up the needle valve yet. I wish there was a more precise needle valve we could gind for this application of tuning a specific flow rate more easily.

[@te10183]

I know this is an old video but it is also more efficient to have the humidifier on the return side as opposed to the supply as you have it

[@purpleblueunicorn]

Awesome video! I've just bought an aprilaire 500 without knowing what it really was. Got if for 50$ and was wondering how efficient it was. I'm thinking of hooking up to a mini 1.3 gal water heater and trickling the water to almost nothing. Maybe a sediment filter inline would make it work longer and we have very soft water already. I don't even have a furnace and will be feeding it through my EVR and you answered how it works with colder air. I'm still not sure how that works in terms of getting the air flow. Why would the air flow through it instead of the ducts, it steals part of the CFM that would go to the house and acts like an additional vent? Can we control the CFM going through it and would that play with its efficiency? Thanks!!

[@UtmostOutdoors]

It's exactly as you described it, similar to an additional vent. It's a bypass airflow. I would just leave the airflow wide open while in the seasons you are using it. I'm not sure getting a hot water tank specifically to supply your humidifier would be good value. I bet just using a needle valve to lower the flow rate a bit and installing it with whatever water supply you have available would be a good start. Thanks for watching and commenting.

[@DjPTL]

Incredibly helpful

[@classicalconcerto6742]

My humidifier uses cold water and it's not so easy to switch to hot water. In order to improve water evaporation, I am thinking of taping the supply line (copper) on the exhaust pipe with metal tape so that the water picks up heat from the exhaust pipe and gets warmed up before feeding into the humidifier. It's very convenient to do. Any comment?

[@UtmostOutdoors]

I have no idea... Just so long as it's a plastic exhaust pipe then you shouldn't melt the line. I'd avoid doing it if it's an old furnace with metal exhaust, unless you're using copper water line. I'm not sure you'd have much heat rise unless you have a very large surface contact area, but I also don't think you'll hurt anything?

[@classicalconcerto6742]

@@UtmostOutdoors Yes, it's copper water line. Exhaust is sheet metal. Thanks for replying!

[@UtmostOutdoors]

Cool! I'm curious how warm you get the water with your copper pipe heat exchanger. That might actually be a pretty efficient way of harvesting some otherwise wasted heat!

[@classicalconcerto6742]

@@UtmostOutdoors I will keep you posted! 🙂

[@classicalconcerto6742]

@@UtmostOutdoors I ran the line on the exhaust with a metal tape, maybe 2.5ft long... a little disappointed, water is warmed up maybe only by a few degrees. The transfer of heat from the exhaust exterior to the water is not efficient because there is little contact and the tape is not much help. I was tempted to run the line inside the exhaust but I quickly rejected the idea out of rust concern. End of story! 🙂

[@itzgametimevip1111]

Excellent information

[@UtmostOutdoors]

Glad it was helpful!

[@Hiwinders]

Very helpful!

[@UtmostOutdoors]

I'm glad you found it helpful!

[@PaulHVAC1]

It’s interesting that you are stating that your choice is either a by-pass humidifier v sponge drum humidifier. I am a HVAC technition and I found my AA.600 is a huge waste of water. Roughly about 10% going in the air and 90% straight down the drain. I looked at my water bill and was disappointed. I even run a electronic water saver control. You state the sponge drum is 100% efficient but because you say you have to change the sponge quite a lot. I’m in Alberta and you do not have to, just every start of winter is fine, but the real knock on them is the mineral build up and fungus in the pan is the real problem. So sponge drums do require a hard cleaning every start of winter along with a new sponge drum. But the by-pass also need a new pad and clean up too. What you have missed completely is that the better alternative that I am going to is the desert spring humidifier. The wafer drum never needs replacing, and you have a automatic timed flushing of the water in the pan ( greatly reducing mineral buildup). So you get a 100% water efficient humidifier, No cost of new pad or sponge drum and most important no wasteing money of water constantly running down the drain. Yes you will do a little cleaning once a year, but you will have to with the other humidifiers too.

[@UtmostOutdoors]

Thanks for the insight. I had never heard of that type of humidifier before.

[@NikeMikey101]

I dont get it. Do people not realize why a mirror fogs up when taking a hot shower vs cold 😅 Great video to show that Hot is better. But no idea why cold is even an option

[@UtmostOutdoors]

I know it may seem obvious that hot water would increase humidity more, but my question was "by how much". I wanted to know if the increase would justify the cost of heating the water. This was more an exploration of the "why" rather than proving one option superior to the other. I think either option can still be valid, although I did find the switch to hot to be worthwhile.

[@GF-zh7sv]

I was told by a plumber not to use hot water as it has more calcium buildup over time and you'd need to change the tube very often.

[@SerenoOunce]

It doesn't matter if HOT is more efficient. A HOT supply is loaded with minerals. Being infrequently used, deposits will damage the pipes and valve, and contaminating the sponge media. Not to mention it takes time for water to get from heater to humidifier. At which point a call for cooling will have ended anyway.

[@richardtenamore3109]

I think that you should subtract the heat energy in the hot water taken from your water heater and subtract it from any net gain you may have calculated. That heat wasn't free!

[@UtmostOutdoors]

This is an excellent point. I did actually factor that in by calculating the cost per liter of cold water vs cost per liter of hot water, so at the end of the calculation the energy used to heat the water is factored in. I did not factor in the energy from the hot water partially going into helping to heat the air, so that would be an added bonus during the winter.

[@foxgun100]

I just use a $12 plug in vaporizer to boost % on really cold spells. 😮

[@Colossaltitannwkwbend]

Z Show me the mist

[@Studio69Fan]

I’m installing a generalaire humidifier myself and have tied into the hot water. Thanks for confirming my suspicions. 👍 Also, I watched this video last week and thought you might be interested…. kzbin.info/www/bejne/i4icZIeZoLBmkJI 🙏✌️

[@bigdaddy4975]

Hot water is full of calcium deposits that would destroy that humidifier in probably less then a year

[@UtmostOutdoors]

This type of humidifier has a replaceable pad that is designed to be replaced each 6 months to a year depending on use. As an update, I am still running the same pad today (11 months later) on hot water and it seems to be functioning well still. When the time comes to replace the pad, the rest of the humidifier is in perfect condition as expected.

[@ttp_007]

Great work! Thanks for the video!