# Use radiant heat to heat an 1800 sq ft house



## spark25 (Nov 1, 2013)

Hi,

A customer wants me to install electric radiant heat in his 1800 sq ft house. The mats I have researched seem to be only for small areas like bathrooms or kitchens. What products have you used to heat entire homes? It will be installed on a concrete slab. She will be installing laminate flooring as well.

Thanks


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## backstay (Feb 3, 2011)

spark25 said:


> Hi,
> 
> A customer wants me to install electric radiant heat in his 1800 sq ft house. The mats I have researched seem to be only for small areas like bathrooms or kitchens. What products have you used to heat entire homes? It will be installed on a concrete slab. She will be installing laminate flooring as well.
> 
> Thanks


The products for small areas is floor warming, not heating.


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## FrunkSlammer (Aug 31, 2013)

I've installed Nuheat cables... works really well. Puts out a lot of heat and if the house is sealed properly and insulated properly, it'll be more than enough heat.


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## backstay (Feb 3, 2011)

FrunkSlammer said:


> I've installed Nuheat cables... works really well. Puts out a lot of heat and if the house is sealed properly and insulated properly, it'll be more than enough heat.


Link please.


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## BBQ (Nov 16, 2010)

FrunkSlammer said:


> I've installed Nuheat cables... works really well. Puts out a lot of heat and if the house is sealed properly and insulated properly, it'll be more than enough heat.


So you have run the heat loss calculations?


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## BBQ (Nov 16, 2010)

I went to the nuheat web site and I can't find anything that says they are intended for whole home heating

http://www.nuheat.com/download.html?file=/docs/nuheat-specification-data.pdf


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## Chris1971 (Dec 27, 2010)

spark25 said:


> Hi,
> 
> A customer wants me to install electric radiant heat in his 1800 sq ft house. The mats I have researched seem to be only for small areas like bathrooms or kitchens. What products have you used to heat entire homes? It will be installed on a concrete slab. She will be installing laminate flooring as well.
> 
> Thanks


If they want electric heat, sell them electric baseboard heaters.


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## wcord (Jan 23, 2011)

backstay said:


> Link please.


Don't know if this product is available in the States, but here is a link
http://www.flextherm.com/en/products/cable-system/green-cable-concrete

and

Can radiant floor heating be used as the primary heat source for a room? 
Radiant floor heating can be used as the primary heat source for a room. Several factors must be considered: the level of subfloor insulation, the size of the room, the exposure of exterior walls, the window coverage, the desired comfort level and the system’s output.


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## backstay (Feb 3, 2011)

wcord said:


> Don't know if this product is available in the States, but here is a link
> http://www.flextherm.com/en/products/cable-system/green-cable-concrete
> 
> and
> ...


I heat all my buildings with radiant floor heat, hot water from a wood boiler. Floor warming heat systems are not the same.


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## wcord (Jan 23, 2011)

backstay said:


> I heat all my buildings with radiant floor heat, hot water from a wood boiler. Floor warming heat systems are not the same.


you are correct. 
one uses water, the other uses electrons:whistling2:
Usually in floor electric heat for main heat ( not supplemental ) is installed at 10w/sq foot.
I did a few houses in the past which used ceiling radiant heating panels. They worked really really well. The heating costs were 1/2 of their neighbors.

Depending on one's physical ability, a wood boiler, may not be possible. Did the wood thing , It was a lot easier to work the hours, I spent on chopping, stoking cleaning etc, and pay the electric bill for my electric furnace.

It would be interesting to compare electric boiler costs for water vs electric cable costs. And I wonder if there is a way to compare the quality of heat, Personally I think wood heat is awesome

here is a link for whole house heating costs,

http://www.warmup.ca/ca/in-floor-heating-running-costs.phtml


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## backstay (Feb 3, 2011)

wcord said:


> you are correct.
> one uses water, the other uses electrons:whistling2:
> Usually in floor electric heat for main heat ( not supplemental ) is installed at 10w/sq foot.
> I did a few houses in the past which used ceiling radiant heating panels. They worked really really well. The heating costs were 1/2 of their neighbors.
> ...


But adding cable to the top of a existing floor will not be capable of whole house heating. The thin layer of covering would not keep the heat needed to output the Btus in anything close to comfort. You would burn your feet. That's why those electric heating cables are now buried in sand under the slab.


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## wcord (Jan 23, 2011)

backstay said:


> But adding cable to the top of a existing floor will not be capable of whole house heating. The thin layer of covering would not keep the heat needed to output the Btus in anything close to comfort. You would burn your feet. That's why those electric heating cables are now buried in sand under the slab.


I don't know what products you use in the States.
We have 2 types. One for in the concrete like hot water piping, and the type you are referring to,which sits in the mortar.( 2 to 10 watts sq foot)
The Thermostats, measure both the floor temperature and the ambient temperature of the room. You can program the unit for maximum floor temp so you wont cook your feet. Its really no different than your hot water heating system, where you have manually adjusted the water temperature for the piping, and the room thermostat turns the circulating on.
Same concept, different energy source.
I have done a couple of homes, where the top layer system was used as the only heat for major areas. eg attached, enclosed sun rooms, with no other heat source. Renovated a 1950's ranch style where the surface type was used to heat one entire wing. That customer is exceptionally picky and I have yet to receive a complaint for that section of the house ( master washroom, master bedroom, 2 other bedrooms. combination of tile and carpet for coverings.


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## FrunkSlammer (Aug 31, 2013)

backstay said:


> Link please.


Seriously some of you old guys need too much hand holding.

http://www.nuheat.com/floor-heating/electric-floor-heat/cable.html

I have only installed the cable system as a replacement to baseboard heaters. All I know is the customers love it, their rooms feel warmer and they use less electricity. I'm just saying if you built a house properly with the Nuheat Cable system in mind, I can't imagine it being a problem heating a home.


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## Whidbey (Aug 17, 2013)

I installed a small area of this in a bathroom for a customer in August (50 sq ft). They called me last week to tell me how much they liked it. Installation was easy. This stuff can take a lot of abuse during install. Cut to fit, staple it to subfloor, walk on it. Paid about $450 for materials. It's better than crawling around weaving wire.

http://www.carbonicheat.com


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## backstay (Feb 3, 2011)

wcord said:


> I don't know what products you use in the States.
> We have 2 types. One for in the concrete like hot water piping, and the type you are referring to,which sits in the mortar.( 2 to 10 watts sq foot)
> The Thermostats, measure both the floor temperature and the ambient temperature of the room. You can program the unit for maximum floor temp so you wont cook your feet. Its really no different than your hot water heating system, where you have manually adjusted the water temperature for the piping, and the room thermostat turns the circulating on.
> Same concept, different energy source.
> I have done a couple of homes, where the top layer system was used as the only heat for major areas. eg attached, enclosed sun rooms, with no other heat source. Renovated a 1950's ranch style where the surface type was used to heat one entire wing. That customer is exceptionally picky and I have yet to receive a complaint for that section of the house ( master washroom, master bedroom, 2 other bedrooms. combination of tile and carpet for coverings.


What was your install price per Sq ft?


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## wcord (Jan 23, 2011)

backstay said:


> What was your install price per Sq ft?[/quote
> 
> If we are on the job already,and no extra trips, a small bathroom will cost about 370 for cable and thermostat. Instal is another 250 to 350 not including bringing power to the stat. So $ 12 to $15 per sq ft
> A larger room can drop down to as low as $8 to $9 per sq .
> ...


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## backstay (Feb 3, 2011)

So at $8 per sq ft the 1800 sq ft house heating system, not including a service panel upgrade If needed. Would be $14,400,


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## wcord (Jan 23, 2011)

backstay said:


> So at $8 per sq ft the 1800 sq ft house heating system, not including a service panel upgrade If needed. Would be $14,400,


Probably closer to $12k. The cost of the cable per sq ft drops as the area covered gets larger. Number of thermostats or slave relays. And depending on which brand, hot glueing the cable every 3 to 5 feet, allows for longer runs, faster install. Some brands dictate the maximum length between the supports. Small rooms are pricey per sq. It's not cheap, that's for sure.
And without duct work, no AC.
If it was my house, hot water heat exchangers in the duct work, with individual room stats, infloor electric wherever there is tile, just for comfort, not general heating.
Its almost impossible to balance 2 different systems if both are being used to heat the building. Thats why the stats are set up so you can chose floor or ambient room temperature.
But if a customer wants it, who am I to argue with them. I just make sure that they understand the decision is all theirs and I am doing what they ask.


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## FrunkSlammer (Aug 31, 2013)

An 1800sq ft house does not need 1800sqft of in floor heating. There's many spots I would not bother putting the wire. And if it were doing an entire house, the cost could be pretty low.


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## sbrn33 (Mar 15, 2007)

Chris1971 said:


> If they want electric heat, sell them electric baseboard heaters.


That is what I would have done 30 years ago.
Now I would install cove heat and other types.


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## [email protected] (Jan 29, 2014)

your heat lose calculating most be done 
Not sq ft age which most want to use ,,
there are several out there 
here's one I use a lot ,, BUILD IT SOLAR 
Here's the link ,, 

ps don't forget allow for air exchange ,,
like doors opening,, and such,, 

http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm


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## [email protected] (Jan 29, 2014)

good post ,, love it 
I love radiant heat ,, 
I think bigest problem they have 
want use sq ft age ,, LIKE THE DAY'S WITH BASE BOARD HEAT ,, 
instead of heat lose calculator 
And cubic,,


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## 99cents (Aug 20, 2012)

BBQ said:


> So you have run the heat loss calculations?


Have to agree with you, BBQ. It's why electric heat is often included in mechanical specs. They are the guys who determine watts losses for heating.


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## Jerome208 (May 10, 2013)

Around here the climate is relatively mild and 12 watts per sq. ft. would be grossly over capacity for the climate in any house, but electric resistance heat has none of the efficiency problems that a single stage gas furnace or heat pump would have if they were cycling on and off so much. So no calcs really necessary unless there is a doubt about its ability to keep up with heat loss. The downside is that here electric rates are 3-5x gas so gas usually wins. In the PNW, upper Midwest, and Canada, electric is so much cheaper it makes me jealous


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## FrunkSlammer (Aug 31, 2013)

Jerome208 said:


> In the PNW, upper Midwest, and Canada, electric is so much cheaper it makes me jealous


Up here in BC, natural gas is still much cheaper than electric to heat with.. unless you have an eco home and don't need excessive BTU's or kW's, then electric can win out.

I like in floor electric because it's very constant.. not on and off and on and off.. hot and cold and hot and cold. 

Hot water in floor heating I think is the worst for cycling of too hot and too cold.


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## triden (Jun 13, 2012)

A properly installed water floor heat system will be nice and constant like the electrical ones you talk about. Sounds like the water temperature is set to high so you get a huge hysteresis instead of the nice even heat you should be getting.


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## markore (Dec 7, 2011)

backstay said:


> The products for small areas is floor warming, not heating.


 Backstay is from a cold enough climate to ask, is the slab insulated?



FrunkSlammer said:


> http://www.nuheat.com/floor-heating/electric-floor-heat/cable.html
> I have only installed the cable system as a replacement to baseboard heaters. All I know is the customers love it, their rooms feel warmer and they use less electricity. I'm just saying if you built a house properly with the Nuheat Cable system in mind, I can't imagine it being a problem heating a home.


Frunk, I don't know weather to scold you or thank you for that covert link to bongonews...eh...yeah...


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## backstay (Feb 3, 2011)

triden said:


> A properly installed water floor heat system will be nice and constant like the electrical ones you talk about. Sounds like the water temperature is set to high so you get a huge hysteresis instead of the nice even heat you should be getting.


Yes, we run these water systems at 80 to 90 degrees. It depends on how well the building is insulated(heat loss rate). We also use floor stats to regulate, not air stats. This helps to even out the temps when you have solar gain through windows.


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## markore (Dec 7, 2011)

triden said:


> A properly installed water floor heat system will be nice and constant like the electrical ones you talk about. Sounds like the water temperature is set to high so you get a huge hysteresis instead of the nice even heat you should be getting.


I agree and use a takagi tankless to heat a 2000 sq ft space myself, however:

It takes a LOT more planning and design to make sure the correct materials are used to insure even and responsive heat dissipation are in sync with climate and site conditions. Floor vectors infront of large glass areas can help a lot with cold drafts.








There is a lag time in any radiant system for the thermal mass to come up to temp before it starts radiating evenly into the room - therfore radiant is best for areas which will be constantly heated instead of cycled on a schedule.
Kickspace heater air coils under cabinets or in walls are useful in areas which need to be brought up to temperature quickly.


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## markore (Dec 7, 2011)

backstay said:


> Yes, we run these water systems at 80 to 90 degrees. It depends on how well the building is insulated(heat loss rate). We also use floor stats to regulate, not air stats. This helps to even out the temps when you have solar gain through windows.


What brand of floor stats have you been using? They are not too common in stores. :laughing:


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## FrunkSlammer (Aug 31, 2013)

markore said:


> Frunk, I don't know weather to scold you or thank you for that covert link to bongonews...eh...yeah...


Can't believe it took so long for someone to click the link! :laughing:


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## eTom (Feb 4, 2014)

spark25 said:


> Hi,
> 
> A customer wants me to install electric radiant heat in his 1800 sq ft house. The mats I have researched seem to be only for small areas like bathrooms or kitchens. What products have you used to heat entire homes? It will be installed on a concrete slab. She will be installing laminate flooring as well.
> 
> Thanks


When you are planning on installing radiant heating throughout your entire house you will have to look and putting together the system. Most mats are for quick installation applications. They just make the job easier. But you have options for radiant floor heating. You can use floor heating cables that you will configure based on the manufacture installation guide or you can use PEX radiant heating that will warm you floor by using hot water. Both systems can be used, it will be up to the homeowner on what the feel comfortable with and the type of system the homeowner wants.


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## Fredman (Dec 2, 2008)

FrunkSlammer said:


> Up here in BC, natural gas is still much cheaper than electric to heat with.. unless you have an eco home and don't need excessive BTU's or kW's, then electric can win out.
> 
> I like in floor electric because it's very constant.. not on and off and on and off.. hot and cold and hot and cold.
> 
> Hot water in floor heating I think is the worst for cycling of too hot and too cold.



And you are just guessing. I have several customers with in floor hot water heat. Not once have I heard such a ridiculous statement from them. They are by far the most stable, comfortable systems out there. 

Um, stick with holding your buddies hand, or whatever.. :whistling2::laughing:


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## FrunkSlammer (Aug 31, 2013)

Fredman said:


> And you are just guessing. I have several customers with in floor hot water heat. Not once have I heard such a ridiculous statement from them. They are by far the most stable, comfortable systems out there.
> 
> Um, stick with holding your buddies hand, or whatever.. :whistling2::laughing:


Defensive much? 

I'm just saying I think it sucks from personal experience and you're saying your customers think it's good enough to not complain about to their electrician.

Potato, Potato. :whistling2:


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## LGLS (Nov 10, 2007)

eTom said:


> When you are planning on installing radiant heating throughout your entire house you will have to look and putting together the system. Most mats are for quick installation applications. They just make the job easier. But you have options for radiant floor heating. You can use floor heating cables that you will configure based on the manufacture installation guide or you can use PEX radiant heating that will warm you floor by using hot water. Both systems can be used, it will be up to the homeowner on what the feel comfortable with and the type of system the homeowner wants.


Uh, the electric mats used under a floating floor or the under carpet mats are not considered a heating system here by my building department. Although I'm using them with great success on my entire 1st floor, I had to retain the existing hydronic baseboards. Mind you, all the windows are Anderson, all of the exterior doors are top of the line, and I completely gutted the entire floor, changed the layout a bit, and had the entire exterior spray-foamed. Basically, it's a giant thermos.


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## Fredman (Dec 2, 2008)

FrunkSlammer said:


> Defensive much?
> 
> I'm just saying I think it sucks from personal experience and you're saying your customers think it's good enough to not complain about to their electrician.
> 
> Potato, Potato. :whistling2:


I think my first personal experience with a bender sucked. Then I studied up and found out what the mass majority does and why before I went onto this forum and started blabbing about how all benders suck. :whistling2:


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## Deanos01 (Feb 19, 2014)

I installed a Nuheat mat in a bathroom, measure the area twice and they cut the mat to specs and put the wires anywhere you need for the tstat. The only issue I had is when installing the mat the thin set was difficult to spread over the top, the mat kept bubbling up and I had to work the bubbles to the edges. Takes a 1/2 hour to heat the floor, but only draws three amps for about a 12x12 bathroom.


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## captkirk (Nov 21, 2007)

I installed the rope type heating cable In my kitchen and I think it is awesome. I installed it because I wanted to remove the radiator to save space. And its worked out great.


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## Tsmil (Jul 17, 2011)

FrunkSlammer said:


> Up here in BC, natural gas is still much cheaper than electric to heat with.. unless you have an eco home and don't need excessive BTU's or kW's, then electric can win out. I like in floor electric because it's very constant.. not on and off and on and off.. hot and cold and hot and cold. Hot water in floor heating I think is the worst for cycling of too hot and too cold.


I have a hot water in- floor heating in my basement. It had terrible temperature cycles as you said. I since modified the system and now is very consistent. I monitor the return water temperature and use that for cycling the heat. I also keep the water circulating. Works very well.


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## Fredman (Dec 2, 2008)

Deanos01 said:


> I installed a Nuheat mat in a bathroom, measure the area twice and they cut the mat to specs and put the wires anywhere you need for the tstat. The only issue I had is when installing the mat the thin set was difficult to spread over the top, the mat kept bubbling up and I had to work the bubbles to the edges. Takes a 1/2 hour to heat the floor, but only draws three amps for about a 12x12 bathroom.



No doubt it's a great product when used for it's intended purpose. But there was some talk about using it for Primary heat.

:blink::laughing::no:

Sorta like installing four go-cart motors in my Suburban. 
Sure it will work for a while but...


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## markore (Dec 7, 2011)

Fredman said:


> like installing four go-cart motors in my Suburban.


Did somebody say tesla model X?


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## Deanos01 (Feb 19, 2014)

Ya in the bathrooms


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## Fredman (Dec 2, 2008)

markore said:


> Did somebody say tesla model X?


:laughing:

Not quite the same idea. 

On the other hand, I would love to have one of the electric motors out of that thing. Make one hell of go-cart for my boys.


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## woodchuck2 (Sep 18, 2009)

I see this is an older post but if this were my customer and they were requesting radiant floor heat but electric then i would speak to them about traditional hot water radiant heat with an electric on demand water heater to heat the radiant. I see this all the time now around here where folks are ripping out there oil boilers and using propane on demand heating units to heat there homes. Far more efficient and less space wasted in the basement/utility rooms. Using the electric unit would do the same thing.


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