Radiant not heating a room with carpet

Chris_82

Ditto the additional radiators, it has always been a problem over nice carpet. Runtal makes nice radiators as well as others. I don't know how large your bedroom is but there are a number of nice fireplace options to consider as well? We once added tubing and transfer plates untill the joist space was full, three plates and multiple 3/8 and 1/2 tubing runs with the rest of the joist filled with pink insulation about ten inches worth as well as the rim joist space filled with 2 inch insulation and foam for all of the penitrations. Never did get that room to heat just by the floor on cold days, near 0, 2 inches of plush foam/rubber padding and a thick wool plush pile rug. But at least we had repeatidly warned the customer this was most likely the outcome. Think rugs and radient think additional heat from something. Anything otherwise is just someone selling you a line. Unless your in a highly insulated home to begin with, and few are.

Jennifer Bittinger

Radiant not heating a room with carpet

This one is a stumper....We installed a in floor radiant heating system in a new house a few years back and the heat works great in the whole house except the master bedroom. (the master bathroom is on the same zone and works) Our theory from the start was the berber carpet and 1/4" thick felt padding were the issue and lack of insulation. The contractor said he fixed the insulation (it was hanging down) and he said he double insulated. Which has helped the situation. It will be fine for most of the day and then at night the temp drops and it takes until about noon the next day to come back to temperature. We have had the representative from the company that did the radiant design for us come out twice with us he had us do a primary secondary loop he said he guaranteed that would fix it...well the second time he was out he said that was the insulation (the first time he looked at the insulation and said that it was okay). Now he went out with another plumber and said that all the piping is wrong. Everything heats but this one room. The basement t-stat is set at 70 and it is 80 in there and the floor pipes are cold and never run. That tells me the heat is coming down. Another issue is the huge KING size bed that is sitting on the floor (you cant get your hand under the bed). So there is that whole area where no heat is coming up. Please help....what are your ideas???
Please let me know if you need more information
Thanks!

jp_2

add panel rads

with a huge bed and carpeting, your best bet is to add panel rads. not sure i understood the 80F/cold pipe statement, but sounds also like an insulation problem.

got any pictures? what kind of insulation? how much?
what kind of piping layout? why is the piping all wrong?

Jennifer Bittinger

Brad White_9

Temperature and Arrrrrrgh! Value

Jennifer, it all gets down to the R value imposed by the carpet ultimately, compared to bare floors. Typically the two flooring materials would have different temperatures. The carpet might have to be run a little warmer to compensate but not so warm that it roasts the padding to off-gassing.

Unless your tubing spacing (density) is different, there is no way to compensate for a water temperature difference. Having a separate water temperature is the most practical way. (You can see how these variables interact: tighter spacing/lower water temperature; wider spacing/higher water temperature; thicker floor covering/higher water temperature... you get the idea.

The bed part is contributing if that low to the floor. I usually do not worry too much if there is the nominal 6-8 inches (the sweater boxes have to go somewhere!).

Knowing the calculated heat loss of the rooms in question, the floor structure layer by layer and the available radiant floor area (how much "radiator" you have versus the heat loss) are key bits of information. The tube spacing, water temperatures also. Each affects the other. A guess is better than nothing.

You are right in that if the floor below is being warmed the insulation is deficient. The integrity of that is more important than the thickness. R-19 is normally a default below a radiant floor. But a sealed installation is critical. It all works together.

EDIT: As JP suggests, panel radiators may be an expedient solution. The warm floor becomes a nice baseline (make it as good as you can). But chasing that can take far more time and effort than installing a panel radiator or two strategically. Good call, JP.

Jennifer Bittinger

reply to j paul

I dont have pics with me but I will get some and post them.
There is batts of r-19 insulation.
At first the insulation was hanging down, and now the contractor said he stapled it up right and he said he even added extra insulation.
The representative is supposed to get us a diagram of what is there. He said there is no mixing valves, maybe it is his first rodeo, but we have mixers on every zone. The circulators are on the supply (we have been doing that on every job since we read Pumping Away)
Actually at first the pumps were not on the supply, they were on the return. But after the rep had us change the piping and pipe a primary loop (at our cost) we had a terrible air problem (at our cost) and we then repiped and put the pumps on the supply (at our cost).

ALH_4

add panel rads

I agree with j paul. You need supplemental heat in that room. Carpet kills the output of radiant floors. I would not recommend installing carpet over radiant floors. There are pads adverised as "radiant friendly", but any layer of insulation on the floor greatly decreases the output.

jp_2

Heat going down

that sounds like a problem to me. I'd be looking into why the basement is so warm, you are force too much heat into the piping to keep the uppper room temps comfortable. is it an ICF basement, that is, a well insulated basement?

seemS if done right you would have lower water temps and greater efficiency and lower operating costs, unless the warm basement is a plus!

ps thanks for the nice comment brad!

Dave Larsen_2

seperate zone

I don't think I'd be jumping on the radiator bandwagon yet! there are to many unknowns to make that decision. where is your thermostat located? Is there a possibility that the bedroom can be seperated from the rest of the house and run on its own Tstat? what is the BTU load of the room? If your heat loss calcs look good then there is no reason to suppliment the room with radiators, when just seperating it from the rest of the zone can work. The warm basement does sound like there may be an insulation problem, which will also add to the lack of heat in the bedroom.Sounds like some of the heat is going down rather than up.

Paul Pollets

I'd wanna bet...

that aluminum transfer plates were not used, and this is a "joist-bay suspended" application.

Someone didn't do their homework on the heat loss calcs.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Dale

joist bays

As the other posts suggested there are a number of things to try. Before I spent any money on plumbing I would get an inferred camera picture of all the surfaces arround this problem room with the heat turned way up. Sometimes the joist end bays aren't insulated well or left unsealed. If no transfer plates were used you may want to take the carpet up and go to a solid surface and area rugs by the bed. The greatest heat loss is the walls and the tube near them needs to give all the heat possible. It's easy to find out the tube temp in the offending room and see if it's maxed out. You may find you need a mix of solutions but spend the $ on the camera so you don't ready fire aim.

Ericjeeper

what are the room conditions?

Large windows? walkout patio door? Homeowner mentioned losing ground at night. That tells me she is getting some solar gain throughout the day.And then losing her heat out the windows at night.

mb_2

crossed stat wires

check if the basement stat and bedroom stat wires are crossed in your controller

John@WattsRadiant

What temp water?

What's the water temp for this zone? Have you tried increasing it?

Weezbo

wool carpet 2\" thick ....

you will have the radiant backing for that carpet installed ....

last min switchy changes should be governed by some sort of law..*~/:)

it is almost in the same realm as the lawsuit the Wirsbo wholesaler is considering levying against me for the shock of seeing Red O2 Tubing in the back of my van

the other thought that might work is try lowering the tmps in that room and turning the temps of various rooms higher for a while....it may be there is a wire to water problem... do you have an HRV? turn it on for part of your test..maybe the house will balance itself out a bit....depending on the water temps or designe of your radiant system...you may have some conflict going on within the system that does not lend to "Comfort" within the building . what i mean by that is the reaction times might lagg and lead the thermostats...

i also think that you should circulate water until it runs clear in each loop of every zone...

here is a neat method, put some food colouring in a bucket of water..when the water comes out that colour cycle it three mins charge the loop and move to the next one.

long time ago, i saw a three way porportional mixing valvegooffed up with some wood chip and the flow was like zilch through the loop . so check those supply and return temps too.

Rochoc

Carpet

Without a proper heatloss it's all speculation. We have plenty of projects including my own home that heat through carpet just fine. The problem comes with poor design a tile floor will require a different temp than a carpeted one, mixing floor coverings on the same zone is bad medicine. Insulation done properly is crtical, lack of perimeter insulation is #1 for bad performance. I like staple up onix with the foil back insulation, again proper design using a decent software takes all the guessing out. Hire a professional and ask for references, maybe take a visit to some of his/her recent projects, there are plenty of lousy contractors out there, weed them out, sounds like you found two already.

Jim Kelleher
J.E. Kelleher Plumbing & Mechanical Inc
Martha's Vineyard Island

Jennifer Bittinger

The water temperature for this zone is 150 degrees. We started out at 127.2 degrees. The floor temp we got from an infrared thermometer is 82 degrees.

Jennifer Bittinger

The basement is on a separate zone that never runs. Every time we check the temp the basement is much warmer than what it is set at and the pipes and floor are cold.

[Deleted User]

CAUTION,,,, CAUTION,,,

You are approaching critical mass. If you exceed a floor surface temperature of 85 degrees F, people will start melting into the carpet... (Said in Robot's voice from Lost in Space)

Seriously, it sounds as if the floor is doing all it can. If you can't keep the room warm under leas than strenuous conditions, it indicates to me that the construction is not as tight as it was expected to be. Have a blower door test done and see what your infiltration is like. If necessary, as above floor augmentation heat (panels, baseboard, convectors),

Why DO people put carpeting down over the top of a warm floor? Do they REALLY need a place to rap and hold all those allergens?

I've actually offered to buy pairs of Deer Foam slippers if the HO promised me NOT to put carpeting down in thier bed room.

The basement is overheating because the bedroom is struggling to get to temp, running ALL the time, and the panel back losses exceed the basement heat loss requirements and consequently overheats.

Been there, seen that, made my sphincter do the momba...

Omni directional radiant panel my butt...

Also, in the future, buck up and zone the bathroom seperately from the bedroom. In the bath room, you are typically wet, cold and naked and need much more heat there. in the bedroom, the majority of people like a cooler sleeping environment. The two flooring surfaces also have significantly different emmision qualities...

ME

Dave Larsen_2

zoning

> You are approaching critical mass. If you exceed

> a floor surface temperature of 85 degrees F,

> people will start melting into the carpet...

> (Said in Robot's voice from Lost in

> Space)

>

> Seriously, it sounds as if the floor is

> doing all it can. If you can't keep the room warm

> under leas than strenuous conditions, it

> indicates to me that the construction is not as

> tight as it was expected to be. Have a blower

> door test done and see what your infiltration is

> like. If necessary, as above floor augmentation

> heat (panels, baseboard, convectors),

>

> Why DO

> people put carpeting down over the top of a warm

> floor? Do they REALLY need a place to rap and

> hold all those allergens?

>

> I've actually

> offered to buy pairs of Deer Foam slippers if the

> HO promised me NOT to put carpeting down in thier

> bed room.

>

> The basement is overheating because

> the bedroom is struggling to get to temp, running

> ALL the time, and the panel back losses exceed

> the basement heat loss requirements and

> consequently overheats.

>

> Been there, seen that,

> made my sphincter do the momba...

>

> Omni

> directional radiant panel my butt...

>

> Also, in

> the future, buck up and zone the bathroom

> seperately from the bedroom. In the bath room,

> you are typically wet, cold and naked and need

> much more heat there. in the bedroom, the

> majority of people like a cooler sleeping

> environment. The two flooring surfaces also have

> significantly different emmision

> qualities...

>

> ME

Dave Larsen_2

zoning

I think you guys are over looking some thing here. She states in the original post that the bedroom is on the same zone with hardwood flooring. If her surface temp is capable of 82 degrees but her thermostat is satisfied before this particular room comes up to temp,then making this a separate zone is a logical fix. We all need a bit more info to make a proper call here.

Rochoc

Lost in Space