Electric Radiant Heat

DaveGateway

I was thinking of using electric radiant heating in the tiled areas of my house like the kitchen and baths, as the sole source of heat for those rooms. How do the electric filament mats under the tile hold up over time and as compared to hydronic radiant tubing? I don't want to rip up the tile in 5 years. Can electric radiant be used as a sole source of heat?

Thanks

Mike

Constantin

Hey, i'm just a homeowner...

In theory, such systems work great... the matts are very thin and easy to hide in the mud for the tiles. Yet, I would never use them in a house that has continual occupancy... at least not where I live. Electricity costs around here are simply too high ($0.10-$0.13/kWh).

On the other hand, such a system might be very interesting for a cottage, particularly if you can find a way to activate it prior to your arrival. Warm floors underneath are a wonderful thing!

Where I see the most logical application for electrical resistance heating is retrofitting towel warmers. We're still debating whether we want to tie our radiant system into towel warmers or not. That is, we haven't decided whether we want towel warmers or not, considering the somewhat perplexing pricing I have seen thus far for the materials.

heatboy

Do you have room......

for 3/8" or 5/16" PEX in a mudset? If you do, an electric boiler would be a good choice. I have done this a few times where no other heat source was available. Hydronic radiant can always be upgraded later with some other heat source.

hb

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Kal Row

i you get the new low volage

semi-conductor strip type, then you can add in redundanncy, and also have a solar collector battery charger - should offset the elec costs

Robert O'Connor_3

> semi-conductor strip type, then you can add in

> redundanncy, and also have a solar collector

> battery charger - should offset the elec costs

Robert O'Connor_3

Electric Radiant Heat

I was actually thinking of using a solar array with net metering in the back yard to offset the cost of using electric heat. I have easily accessible 1 story roof area that could support a PV system that could meet 200% of my current usage.

The rest of the house I will use hydronic tubing under engineered wood floors.

Where can I find this new lowvoltage semi-conductor strip type?

Constantin

Wait...

You're considering using a PV array to heat electric resistance heat? Are you off grid or is there a specific reason you're not going to a direct solar gain system that circulates hot water down to a tank and then through the house?

The best PV systems maybe get 15% efficiency, whereas solar water heating can approach 50%. Not only is solar water heating usually cheaper per sq ft of panel, it also usually results in smaller panels. Seriously, I don't see how it could be cost effective to heat using a PV array.

Kal Row

i agree

while here is the link for the electric floor i was talking about http://www.warmfloor.com

i agree with heatboy - once you get a good Hydronic system, with manifold and storage tank in place, you can knock yourself out with any number of heat sources


in fact, if you happen to have a swimming pool - you can float a couple of layers of foam board and seal that in, with a good insulating blanket, and put up a serious solar collector on your roof, then, one good day of sunshine will give you many days of slab radiant at 110 supply and 90 return – just make sure you anti-microbial treat the water or you will have a legion of legionnaires….

DaveGateway

Electric Radiant Heat

I was originally looking at PV to just offset my electric bill. The rebates from LIPA are 4.50 per watt, and if I do most of the install myself, initial investment will be minimal.

Since I have such an excess of south facing roof area on my garage I was thinking of expanding the PV to take an edge off of my heating bill by using it to offset the cost of electric radiant heat, just in tiled areas, not the whole house.

While a direct solar gain system may be more efficient during the heating season the PV will be rolling back my meter all year to make up the cost. So even if during the heating months the PV doesn’t have the capacity to support the electric radiant when it is in use, it will catch up when the weather is warm.

Doing a Direct Solar gain system would probably also be impractical since my garage is 70 feet away from the house and even if the pipes are buried and insulated, the heat loss would probably be too great by the time the water reaches the house.

Does this seem like a sound idea? Are my assumptions correct? I'm just in the beginning stages of planning this so any informed insight would be great.

Mike

Mike T., Swampeast MO

This might be the electric product you're looking for...

Step Warm Floor

Curious: When you are already planning a hydronic system for the other areas of the house, why are you planning on electric for the tiled areas? If your underfloor heat transfer method is sufficient for engineered wood floors, it's almost certain to be sufficient for ceramic tile, mortar and cement board...

If you're wanting to have warmed tile floors during periods when the boiler isn't required for the rest of the house, you can just use electric as an adjunct.

Many of the electric floor products I've researched (and the one I used, Warm Floors--NOT same as above) get rather "iffy" when it comes to providing FULL heat for a space--particularly baths and kitchens where much of the floor space is taken up with cabinets, appliances, etc.

The product in the link seems exceptional however as its output is proportional and they show the ability for some pretty hefty outputs. Not certain if it would be well-suited to solar projects--transformers induce a bit of loss and from what I know about PV you have to design for the least possible system loss because of the extremely low efficiency of the electric production.

p.s. Would really like to hear reports of people who have used the above product. It really sounds interesting...