Opinions on radiant electric floor heating?

[Digger]

We installed under-floor electric heat from Warmly Yours (www.warmlyyours.com) in two bathrooms of our previous house. Best thing we did to it, and we did a full remodel of the place. These were very small bathrooms, perhaps 100 sq ft, and only about 70 of that had heating mesh under it (no need under tub, impossible under toilet and sink, etc.). As I recall, it was costing us only a few cents per day to heat each of these and it was the ONLY heat source in each bathroom. One was over an unfinished / unheated basement, and the other over an unheated crawl space. We kept the floors themselves at 82, and used an in-floor sensor to control the temp rather than an ambient room temp sensor, and I would strongly recommend that. These were the two most comfortable rooms in the whole house, and we live not far from Philadelphia (some cold days in winter). I found the Warmly Yours folks to be experts at offering advice, very honest, and able to give you a pretty good idea of what the heating cost would be prior to actually purchasing it, based on your area, type of construction, etc.

Our new house has hot water radiant floor heat installed by the previous owner in two bathrooms, and we do NOT like it as well. It takes longer to heat the floors than the electric type did, and you're heating water in a tank that then gets transferred to tubing in the floor, where the heat is transferred again. There has to be some significant loss in all that, rather than just having the elements right under the floor. H2O-based radiant heat is probably great for solar, where one has it all over the house and can make use of a boiler, and other large-scale operations. For a small space, though, I'd take the electric type any day after owning both.

You asked about thermostat, on/off, etc. We used the programmable thermostat Warmly Yours supplied. Can't remember which one it is, but you can find it online at their site (they used to sell only one). It did modify the power a bit rather than being simple on / off. Higher current was used when starting up after being off overnight or during the day, and less when the system was just cycling on and off to maintain a temp.

When we build our next home, the entire thing will be heated ONLY with radiant floor heating. Good Luck with it!

I use the Warmly Yours also and was apiece of cake to install. I also like their thermostat. I think they give you 10% off on your second order etc.

 

[pete]

Hi Pete: you're the first person to mention zoning. I didn't think it was normal to retrofit a zoning system to a single-zone unit. I guess it's all just a matter of duct work and controllers.

it's not, but it can be done . . as long as you don't create a zone that's too small . . a 50/50 (or reasonably close) split is OK . . but be sure the unit can deliver the BTU's you need . .

I presume I could still make use of my Aprilair 8870, correct? The zoning control would have to come from either the ELK or Aprilair's controller (?). I think the system is sized OK, but it may be worth having someone come in to verify.

control is the easy part, each stat will light up the heating unit, plus open it's damper. . is the unit heating the basement now ?

Thanks, I think you're onto something here. My *main* concern with using the central HVAC for both upper and lower levels was the difference in heating needs. To satisfy the basement's heating requirements, would run me out of the house upstairs.

usually a decently insulated basement is less of a load than a framed upper floor . . less loss thru windows and none thru the roof . .

Pete C

 

[politics123]

Hi Folks,
I'm in the process of remodelling my basement: the end goal is to be a completely seperate apartment. The house is a split-foyer BTW. Our primary heating/cooling is a single stage heat pump (5t), for roughly a 2000sq' house. Split foyer implies the basement is roughly 1/2 the space.

Anyways, I'm wondering if you think electric radiant heat is worth the cost? Obviously the basement gets pretty darn cold in the winter, but there is one below-grade wall that spans the length of the house that is still bare block.

What I'm *really* trying to avoid is a future tennant littering the place with portable space heaters: those things will surely spin the meter. How well can radiant floor heating suppliment the primary heating system? Do you think this would be overkill once the basement is [fully] insulated?

Lastly, are the controlers for these things simply on/off, or is the power to the heating coils modulated? I have an existing Aprilair 8870 (IIRC) as a 'dummy' thermo for now, but I would *love* to be able to control both dependant and independant of each other.

Thanks for reading, I'v only recently come across the electric version: think huge heat blanket.

Cheers,
Jamie

So, as an economist, I can recommend something that would prevent tenents from indiscriminantly spinning your meter --> install a sub-meter and charge them for the amount of electricity they consume. A decent system shouldn't cost too much --> and should pay for itself soon enough!

There's a _LOT_ of B/S about radiant floors and energy savings. A lot of people suggest that because your feet are warm, you can lower the temperature. Most studies indicate that people are comfortable at the same temperature as they are with forced-air heat (if they measure comfort after the fan turns off to eliminate any drafts.) A resistant-heat radiant system would cost more to operate than an efficient heat-pump operating in heat-pump mode. It should be equally efficient as a heat-pump operating in emergency-heat mode.

IMHO, if you're after energy savings, the best way to save money is from an ultra-efficient source (not electricity!) -- geo-thermal heat pumps, solar, ultra high-efficiency heat pumps or furnaces. You can tie any of those into a radiant system if you want the "warm feet" feel. However, the savings is coming from the efficient heat source. Tied in with an zoning mechanism, radiant heating can improve your efficiently. Yes, you will incur a very large installation cost. Electrical resistance/heat radiant floors are much easier to install... but offer no cost savings.

Most people install radiant heat for the purposes already mentioned -- it's more comfortable to walk on a warm floor. When I finish my basement, I plan on installing it for that reason. However, the basement will be heated from a high-efficiency furnace.

 

[pete]

There's a _LOT_ of B/S about radiant floors and energy savings. A lot of people suggest that because your feet are warm, you can lower the temperature. Most studies indicate that people are comfortable at the same temperature as they are with forced-air heat (if they measure comfort after the fan turns off to eliminate any drafts.) A resistant-heat radiant system would cost more to operate than an efficient heat-pump operating in heat-pump mode. It should be equally efficient as a heat-pump operating in emergency-heat mode.

what price are you willing to pay for comfort ??

I've worked as a tinknocker (sheet metal mechanic, HVAC ductwork) for the past 25 years or so and IMHO there is nothing worse than hot air heat, a hydro air system (hot water coil in the duct) is better than a furnace, but both are to dry, dusty, drafty and stratified (cold low, hot high) for me . . the fan has got to run sometime . .

I got my A/C ductwork for free and still spent the money to put in radiant heat . . heat is made by a 60 gal LP water heater (no boiler), not the most effecient but does the job. . for better effeciency you can use a water to water heat pump (but they are expensive) . .

most of the savings is due to the fact the radiant heat heats objects, not air (think a warm sun on a cold, windless day). . open the door w/ a hot air system and all that heated air rushes out . . because the heat is at the floor (not rising to the ceiling) I set my stats at about 67F and find it very comfortable . . bare feet, shorts and a T all winter long, the wife might put on a pair of sweats, but still goes bare foot . . to the lady of the house, the best thing about heating objects is that the seat is warm when she uses the bathroom . .

the system is very quiet as well . .

for anyone trying to decide if radiant is worth it . . it is !

 

[evperry]

i am also considering ordering this product. what do you think about it so far and do you you think it could be a primary heat source?

thanks.

Funny you should ask about this as I have just remodeled a bath and added radiant floor heating as well. The one I used is from STEP Warmfloor and it is different from the other manufacturers as it is a low voltage system and instead of a wire that heats up (think of a toaster heating element) it is a self regulating thermoplastic membrane. As it warms it allows less current to flow thereby restricting the heat produced. The benefit is that it is entirely safe in wet environments (due to the low voltage) and it does not require a thermostat (although they do recommend one for large rooms), and is less likely to have the single element burn out. It is a relatively simple DIY install (except for transformer electrical connections to 120v). I have mine connected to a UPB electrical switch so I can control from automation system (turn it off on hot days). The web site is www.warmfloor.com