Radiant Floors and Humidifier

TeachMeSteam

I was thinking of installing radiant floor heating. Can I combine this with the use of of the A/C duct system to humidify the air during the winter? I have dry skin and I want to remedy that.

Gordy

Advantages

  One of the advantages of radiant heat is the fact of not needing to humidify. Usually there is a need to lower humidity. This is due to normal humidity from humans,cooking,bathing, and laundry contrbuting to the structure.  The tighter the envelope the more need to remove humidity from the structure to avoid issues. Your HVAC system can help with this.

pipe4zen

ERV or HRV

Air to air exchange could be better. I prefer ERV as it does not remove moisture or lower humidity in the air.

Brad White

A modest and gentle challenge

I would not go so far as to say that radiant heating negates the need to humidify. The type of heating has little to do with how dry the space is.  An exception would be some warm air systems with poor return air paths, which can affect space pressures. Some spaces become negative and others positive, with the net effect being amplified infiltration, the drawing in of unwanted, uncontrolled drier outside air.



Adding heat to a space is entirely a sensible heat (dry bulb only) process otherwise.



As Gordy noted, the tighter the building enclosure, the less humidity is needed, a true statement for any heating system. Outside air is the largest driver of humidity loss, far outweighing surface diffusion.



I will say this in defense of the "radiant heat = less humidity" statement though: Homes and especially new homes with radiant heat tend to be better constructed with lower overall heat losses. Air sealing is a part of this and that goes hand in hand with lower humidity requirements.



My $0.02



Brad

Kungur

So what is my problem??

My house is a super insulated home. 11" exterior walls. I covered all exterior walls with a continous vapor barrier using acoustical sealant on all seams and penetrations. Pella windows throughout.

Yet when I swicthed to radiant floor heat this past Fall my Humidity dropped considerably. To the point that I had a AprilAir humidifier installed and run my blower,minus the burner, to help bring the level up. Even with that I can only get the level up to about 30-32%.The HVAC guy did wire the blower to run on a lower speed because I do not care for the noise. And noise was one of the things I was wanting to eliminate with radiant.

So I wonder what my problem is?

Jean-David Beyer

humidity

I have radiant in-slab heating in my downstairs zone (about 34,000 BTU/hr in extremely cold weather) and baseboard upstairs (about 6000 BTU/hr load there).



I have an indoor-outdoor thermometer with a relative humidity scale also. I also have a little humidifier that boils water to raise the humidity. The indications from these units are often 15% apart. Since they are quite close to one another, I infer that at most one of them is accurate. If you buy a high-price relative humidity meter, you might have some idea as to your relative humidity.



I find I have to humitify a lot of the time to get it up to what I guess is 30% indicated R.H. On very cold days, my Marvin Windows steam up some if it gets up more than that, but today (30F outside), they do not. I do not know how much my house leaks, but my infrared thermometer does not find any obvious leaks except through my back door that has a storm door outside it, and weatherstripping. It is not that the door seems to leak; it is just a cold door.

Brad White

ANY heating system

will lower the RH of a given space when it warms up. Just to clarify my point that radiant does not produce this effect differently than any other.



It sounds, Kungur, that you did all of the right things and yet may not be producing enough routine humidity in your living space. But despite doing all of the sealing and such, did you have the house tested for air leakage, such as a blower door test? In the alternate a tracer gas test, which is more accurate and less common.



If tested, what were the results?



Do you have a fireplace? Gas log open fireplace? Large range hood and possible HRV/ERV?

jp_2

STOP using soap!!!!!

stop using soap on problem dry areas.   no joke, I had facial dry skin for years, switched to water only and a good brisk towel.  no more dry skin.



better yet start taking suana's and you will never feel cleaner. no soap all together!



our body's need surface oil and germs to be health..........

Brad White

New "Room" at the Wall Needed

PERSONAL HYGIENE Got a general personal hygiene question, or a comment to make? Just want to chat with friends but at an acceptable distance? Ask JP!

This is the place.

jp_2

Low down stinkin reply!!!!!

Haaaa........    what i like is when you smell a person comin 15ft away, bathed in deodorant and aftershave or perfume and you still smell them 20 ft later......



often, this smell ain't too pleasant.  

Jean-David Beyer

Skin problems...

I had a skin proplem for a while and my regular doctor could not figure out what it was; maybe fungus infection, so we tried some high price medication for that. Only result was a lightening of my wallet.



Eventually, a dermatologist said to stop using Ivory soap. He said it might be 99.44% pure, but is was the most drying of commonly used soaps. He said to try a moisturizing lotion for a while, and to use Dove soap instead. Problem went away. I do not even need the moisturizing lotion anymore.



Not all soaps are alike.

Gordy

JP

 Are you referencing a Metro Sexual Male?

Gordy

Kunger

 In my situation every year when the house transitions into the heating season it takes about a month to dry out to 30-35%. Which is where I like it.



  Dry enough to keep condensation on windows in check, and humid enough to not issue bloody noses, and electrocution from the carpet gremlin.  I have 50's construction which is as tight as can be with 4 masonary fireplaces house is wrapped with 15# felt paper double hung windows with gasketed storms.  But I also have three women in the house...well two now ones off to college. Showers,cooking, and laundry contribute lots even with ventilation. 





 If humidity gets out of hand I light a fire or two, and that will bring it down. Fireplaces really put a vacum on a house even just one fireplace. So if you have one, and use it there is your reason for being dry. But I would call 30-35% ideal really.

Gordy

Charlie from wmass

I got a new scent for wallies

Ode de Cutting oil. I often smell of this and the ladies swoon! Of course it could be the heat working properly that's making them lightheaded.

Brad White

Aye!

That is a manly scent!

Eau de Huile de coupe

I am sure it is just your charm, Charlie, but that scent is a deal-closer, I am sure.

jp_2

Gordy

I've heard that term once or twice maybe, is that the same as 'Girly Man' or 'Nancy Boy'?



other than that, I do not know.  mainly young teens with their first shaving kit.



round here guys drive older pick ups, have a dog in the passenger seat,  a bud lite in the cup holder........ on and on

Charlie from wmass

Metro Sexual defined

A man who like women but shopping for the latest fashion and going to get both his hair and nails done more. Some times more than the women he chases.

Charlie from wmass

I think we got a bit off

The subject here. I guess the humidity issue could be addressed with the ac ducts and a humidifier but it could lead to mold issues. Dry skin can be combated with better methods than wet air. jd addressed that.

jp_2

ok

them kind don;t exist around here, must be a city thing........

Interceptor

Aprilaire 360

I have the same low humidity problem here. Mine is a 10 year old 1100sf home above 1100sf garage, fairly well constructed and insulated, radiant floor heat, A/C vents in the ceiling. Winter is unbearable without some type of humidification. Dry itchy skin, bloody nose, 1/4" static sparks. I suspect a lot of air goes up and out through the A/C vents and outside air easily enters through the garage below which is difficult to seal with three 10x10 doors. The air handler and ducting is in unconditioned space, I did not want to use it for humidification in fear of bringing cold air into the house. I installed an Aprilaire 360 thru-wall humidifier in a closet. It works wonderfully, I wish I had done it sooner.

Unknown

drink more wtare & less alcohol

duh. 30% dont sound bad & u ned frsh air to ? Depending on the parameters for fungus, a proper sprinkler system might well do the trick

NRT_Rob

radiant, humidity, etc.

Radiant will not lower the humidity in the home beyond the normal temperature related shift of the air temp.



For years I shared Brad's belief that very tight homes have excess moisture, not low moisture problems. And that's true, if you aren't ventilated, and you need to ventilate.



However we built a supertight shop last year. granted: we don't shower, cook, or sleep here. however it's 3500 square feet with 5 to 7 people in it per day and we ran a little floor humidifier 8 hours a day. We had an ERV running at 70 cfm continuous which is about right for any full sized (2ksq ft+) home.



We never got the RH of the space above 25% this winter. I imagine with residential usage patterns we might pick up 5% or so, which barely makes it into the acceptable threshold, but in the end I think with ANY ventilation in a winter climate you are unlikely to have excess moisture issues and may be back to wanting a humidifier.



ERVs do reduce moisture... even the best of them only reclaim about 50-60% of moisture from the outgoing air. they help but they don't solve the issue. Partly because of this and partly because of comfort though, we recommend ERVs in ALL climate zones, we do NOT recommend HRV use in cold climates, though using ERVs in cold climates may require additional defrosting measures for very cold weather.



Hope this helps. Certainly using humidifiers allows for a tighter humidity control year round which is a good thing. how good varies from house to house and occupant to occupant.