Electric boilers
user-7104030
| Posted in General Questions on
We are putting in a 1600 sq ft new build in northern New Mexico (at 6000′) with a slab floor and radiant heat. We plan to have grid-tied solar panels. It seems to make more sense to put in an electric boiler than gas (propane) but electric boilers seem to be uncommon here and we’re not finding much information about brands etc. Any suggestions about which electric boiler to use and options for domestic water heating? Thanks
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Replies
User 7104030,
First of all, can you tell us your name? (I'm Martin.)
All-electric homes with grid-tied PV systems usually use one or two ductless minisplits for heating -- not a hydronic system with in-floor tubing. That said, you probably have your reasons to want to use a hydronic distribution system.
From an energy persepective, an electric boiler is a bad choice -- it will use three times the energy of a ductless minisplit.
One possible option is to use an air-to-water heat pump like the Chiltrix. To learn more about the advantages and disadvantages of this approach, see these two articles:
Air-to-Water Heat Pumps
Another Perspective on Air-to-Water Heat Pumps
User 7104030,
Here is a link to an article that could help you figure out what type of water heater to buy: "Domestic Hot Water: No Perfect Solution."
I understand the appeal of heated floors they were great 90° floors and 72° air. But that was when you had drafty aluminum windows, R19 in the attic and no insulation in the walls. Today’s code built home you will get so little difference between the floor and the air temps you are likely to be disappointed considering how much money you spent heating the floors.
If you ever lived with heated floors you remember how great they were in January but tend to forget about March when have to heat thousands of pounds of slab at night when it is 50° and that afternoon you need AC and your slab is still hot from last night.
Are you cooling the house? If you are spend the extra money and get a heat pump. Then you have options in March and your wallet may convince you to run the heat pump all year.
Walt
> you need AC and your slab is still hot from last night.
The slab won't get hot (< 75F). Which means that it won't continue to radiate heat later in a hot day when the indoor air is 76F. On the other hand, using the slab as an active radiator does interfere with using it as passive thermal mass.
If you are going to use hydronic slab heat, consider limiting it to areas where you will feel it. Less area with tubing will increase the floor temperature, increasing comfort (up to a point).
Your post is really old, but I'm wondering if you are still out there. We are also in northern NM with grid-tied solar, and the contractors are really not familiar with electric boilers. We have hot water baseboards rather than in-slab radiant. Heat pumps are simply not an answer for this retrofit. I'm wondering what you did in the end.