RCMJR & misoilman, tnx for your replies. RCMJR: LDJ appears to have been in business since 1999. According to the LDJ website they claim the boiler is "Great for radiant floor heat systems". I'd be interested in talking to existing users to see how they are getting on with the the system. I took a closer look at their page about the corn boiler and they claim it's thermostat controlled, perhaps it's able to be dialed down. The picture of it looks like a water heater with a hopper sitting next to it. I'll post the url for the corn boiler. The capacity of the water heater portion is eighteen gallons. They also have an option that would allow the boiler to provide hot water for "domestic" use. So would be able to heat water for shower's, washing dishes etc. Right now the utility room has two gas fired water heaters sitting in it, one for the floor heat and one for domestic use, I think. We'd have to talk the heating and plumbing guy that took over from the H&P guy that had been maintaining the system for many years. The retired fellow is still in town and we might be able to talk him into coming over and orienting us with the systems. misoilman: Having the seller comfirm the moisture content of the corn would be the first thing I would insist on when purchasing the corn. I do know from talking with the folks at the elevator, they will not accept corn that is more than 15 percent moisture. I also need to check with the city to make sure there isn't an ordinance that would preclude me from having a small gravity box sitting next to the carport. If the gravity box is small enough, I'd even consider backing it into the carport. Alas, there is no basement on this dream house. Just a thick concrete slab...:-) So We'll probably use a couple of five gallon buckets for transfer of fuel from the box to the hopper. I'd just consider it a form of exercise...:) We're also a bit concerned about the age of the plumbing in the floor as it is original to the house. The impression I got from the house inspector was that the in floor plumbing was put in place then had the concrete poured over it. I'm going to have to have someone that has better eyes than me and know's what they're looking for, look at the blueprints and see if we can find out how thick the concrete is. Luckily, we've secured a "home warranty" from the seller for at least the first year (at their expense), and there is a possibility of extending it through the second year. I should also probably state that the corn boiler is not a done deal as we are still in the early part of the research stage. Although, a friend of ours has suggested we check the website of the Governor of Illinois and see if there are any grants or other incentives that we might be elgible for. Governor Blagojevich (Bla-goy-a-vich, what a mouthful) is very interested in promoting alternative fuels and energy use in Illinois. Here is a link that might be useful: LDJ's Corn Boiler page

I have electric radiant under a tiled bathroom floor. The bathroom is over a crawl space. It was a DIY job and we like it a lot. The floor is nice and toasty under foot now in the winter. I doubt it gives much ambient heat to the room, but you can get 220V radiant heat that is more suitable for raising room temps (ours is 110). Since the bath is only 15sq/ft we are going to add to the existing thermostat to heat the walkway areas of our adjoining kitchen which will have solid red oak floor on top. The manufacturer of our heating coils says they can be used under hardwood, heres how: On top of your subfloor, you attach 3/8 or 1/2 inch wood sleepers, spaced by the width of the heating mat (typically a foot and a half), after you lay the mat between the sleepers, you cover with self-leveling compound up to the level of the sleepers and let cure. When you nail your hardwood, you make sure you nail into the speepers. I have some worries though about the uneven direct heating of the hardwood floor given solid wood's tendency to shrink and expand. So even though I still plan on doing it, and the radiant flooring company says yes, stiill t scares me a little. Now it is much less complicated if you want a floated or glue down installation. Follow the recommendations of the various radiant floor heating companies.

Electric radiant floor heating is to warm the feet, not the room. If you plan on heating the home, pex tubing and some type of boiler is what you need. And sure you can install hydronic radiant heat tubing on top of an existing slab, but unless that slab is insulated, you're going to have constant heat loss to the soil and air where the slab is exposed to the elements. If you live in a moderately cold environment, the heat loss might not be so severe as to cost you that much money, but if you live in an extreme cold environment, your boiler may not do such a great job keeping you warm. Other than the heat loss to an uninsulated slab, the biggest drawback is the slow reponse time to change temperature. You're heating up a large radiant mass, and if it suddenly warms up outside, the home will be too warm and take several hours to cool down. The opposite happens if you are having a warm day, but it's cold at night. It takes time to come up to temperature. You learn to adjust to these quirks and how to use the thermostat to manage the temps most effectively, but if you are used to the instandt response of forced air, you may not care for radiant. If you're used to radiators, you've already got most of the temp control methods already figured out.

The good news is that neither heat nor cold have an effect on wood movement. The bad news is that moisture content does. Is this a genuine wood floor or one of the manufactured floors? If manufactured, I'd consult the manufacturer's literature. If natural wood, each species shrinks and gains on an individual basis. If plywood, with a veneer, the movement is less. But that would be a manufactured floor, which the manufacturer would be able to answer that. If genuine wood, your floor would be constantly moving, just like genuine wood moves in your house from summer to winter. If the wood had a Summer moisture content of 11% in the East when installed, and was reduced to 6% during the Winter, you would get shrinkages of possibly 1/8" per foot of width. If installed in the dry Winter, the wood would expand in the Summer unless your house was perfectly climate controlled, resulting in buckling. Wood improperly secured that doesn't allow for movement will eventually crack. Properly secured, it should fare well. Since heat dries the air, and dry air causes wood to shrink, your floor might move around. I'll have to ask around about this at work and get some other opinions.