Thursday, November 23, 2006

FLOOR OPTIONS -- RADIANT HEAT:
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jsmith4973@a... wrote: "This is interesting and appealing. Would it be practical to use larger sleepers and to cover the tubes with a layer of loose sand instead of the concrete? This would make trouble shooting easier, I would think. The sand could be removed with a shop-vac, stored in bags until the leak is located and repaired. Then it could be put back. The OSB or plywood or whatever, could then be put back in place. I always use drywall or deck screws. Makes repair much easier.
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LAREN: "Radiant floors, even high in a slab, are very slow to react. There is also very little need for an elaborate heating system in a well insulated house."
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I agree that heating requirements for a well insulated house are less and simpler. And because hydronic heating systems are so slow to react, they don't lend themselves to poorly insulated shelter like my mobile home was (and no doubt still is). The furnace rarely shut off otherwise, so we turned the heat down to 55 at night and whenever no one was home. In the morning, I'd flick the thermostat up and the bathroom (right next to the furnace) would be warm in five minutes. Before the house was anywhere near 70, I'd be done with my shower and turn the stat back down to 55 as I rushed out the door. The above scenario is simply not an option with hot water heating systems and it would be incredibly expensive to maintain 70 degrees in that drafty shoe box regardless of the heating system used. (Unless one had a source of FREE hot water as a few lucky -- or rich -- folks do here in the Gem state).
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So it's a bit of a paradox: hot water systems (HWS) are only appropriate for well-insulated homes and yet the simplest of heating systems (wood stove) is more than adequate for a well-insulated home (as well as being the heat of choice for residents of poorly-insulated homes who have access to "free" firewood).
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I think what makes HWS work for the Habitat home which got this thread started is that it is a four zone system. This allows bedrooms to be heated to even lower levels during the day and allows living and kitchen areas to be heated to lower levels during the night. There is a considerable "flywheel effect" so electronic programmable stats would be required which might start warming an area 2 or 3 hours BEFORE that space would be occupied. On the other hand, these same areas would stop heating -- stop circulating the hot water -- 2 or 3 hours before the use of that space would end. This is usually more efficient than heating all spaces to the same temp 24/7 -- even in a well-insulated home.
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Simpler one zone systems = a single $25 thermostat and one $70 circulating pump MIGHT be a heat option for a home with a relatively large central kitchen/dining/living area which could be allowed to cool headed into the evening and night hours. Vents high and low in adjoining bedrooms (or bedroom doors left open at night) would allow sufficient residual heat to circulate for sleeping. These vents and doors could be closed during the day to conserve and retain heat in the central area. I love wood stoves but it seems they're either cooking us to sleep or freezing us to death and very little in between. Using a woodstove to heat water in a HWS and "charge" the solar pancake under the floor would be a way to spread that SURGE of heat out over a longer time period and heat domestic hot water or at least preheat the water before it goes to the water heater. It might also eliminate the need for those "midnight feedings" of the woodstove.
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A sensor near the ceiling on the chimney which allows the circulating pump to run ONLY when chimney temps are above 185 degrees F would make sure that "stealing" heat from the woodstove would not contribute to creosote formation inside the chimney. A "fan control" thermostat could turn the circulating pump ON when air temps vicinity of stove exceed 80 degrees F (or whatever temp setting the owner might choose). When the fire burns down and temps fall below the set level, the circulating pump would turn off and stay off until a new fire was built.
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Whether one uses HWS or not, cheap floors -- based on a layer of sand elevated above grade (for above grade shelters at least) -- can be quite nice. Mike Oehler (sp?) writes about laying down black plastic -- secured to wood "form boards" around the perimeter -- and covering the plastic with carpet for a floor our feet were made to walk on . . . they were NOT made to walk on concrete, for example. He says if you get a low spot, pull a corner back and fill it in with more sand or dirt = no big deal. I read about a boat builder who builds a temporary shelter all around any boat he's building. The floor under the boat is simply dirt or gravel -- concealed by wood chips and saw dust in short order -- but at the back end, he has a "shop" where all his tools and equipment are kept. For the shop floor, he lays down plastic and "sleepers" which are 2x4 (redwood or PT would be nice) -- laying flat and loose = NOT on edge and NOT secured to each other. The sleepers are 16" or 24" o/c and he secures (what they call 1" -- actually 3/4") T&G pine for a floor he can sweep clean. As HIS floor is temporary, he uses finish nails to install it -- which makes the eventual DISassembly much easier AND allows the pine boards to be RE-used again and again. A 4" wide layer of cardboard -- or similar -- under the sleepers to keep them from poking holes in the plastic is a good idea.
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An indoor "deck" of 2x6 could be installed the same way with the standard pencil gap between deck boards -- although that won't be everyone's cup o' tea. Sheet goods (ply or OSB) could also be installed this way (per jsmith's suggestion) but I'd definitely want a gap around the perimeter of the room so that any moisture which ended up underneath would have a chance to dry out. I think any solid floor deck (like ply or OSB) would tend to insulate and further slow migration of heat from a HWS loop to the living space above the floor. This would lengthen what we call "thermal lag" = the time it takes for the heating source to warm the room to a comfortable level.
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I saw one home where they used landscape fabric instead of plastic and there were large plants and small trees growing right in the living areas. Board walks and patio block walks (which adds thermal mass if it is needed) connected various platforms at slightly different elevations where the furniture was and landscape rocks and gravel covered the remaining areas. I love indoor "water fights" so this would be the perfect house for me! Such a "living in a greenhouse" approach would be a natural extension of the earthship approach of allowing sink drains to mainline into indoor planters. (Larger graywater sources like showers and washing machines are usually drained into larger outdoor planters.)
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Consider the more conventional expense of floor joists, insulation, ply or OSB deck, underlayment & vinyl -- or pad & carpet -- and IMAGINE what could be done with that same amount of money spent on landscape fabric (or plastic), gravel, decks or platforms floated on sleepers, and a few plantings from Mother Nature's FREE nursery. Water falls, ponds -- a hot tub built right into the ground -- just IMAGINE it! In fact, I think it's a great code-evasion scheme . . . "I'm not building a house; it's a greenhouse!" (And if I choose to watch TV in my greenhouse or eat in there or sleep in there or entertain my friends in there, who is hurt by that?)
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A 12x12 or 12x? elevated deck/platform could be wonderful and easy to clean if covered with vinyl (no seams!) or T&G wood of some sort. Pallets are an ideal source of FREE flooring IF one has access to a planer. Store-bought T&G flooring comes in shorter, mixed lengths anyway. The T&G edges (on sides AND ends) can be easily and cleanly made with a router and two simple router bits; a third economical bit would do a nice 1/8" radius "round-over" where the two floor board edges meet. A little sanding and a clear oil finish -- natural and beautiful.
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LAREN: "Not one inspector disallowed the system, and none took the time for a tour either."
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Isn't that how it goes? Those stuffed shirts are so sure of that which they know nothing about -- combined with no willingness to learn -- because that might require them acknowledging that just maybe they DON'T know everything. Their fragile egos can't afford that reality. Their minds are made up. I don't suppose we should confuse them with any facts. Ignorance is often excusable. No appetite for continuing education is NOT.
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LAREN: "If you need to store energy, like from a Solar sunspace, then sand under your floor is a real good heat distribution system. The way you get the heat into it is by blowing air through tubing (4" un-perforated, corrugated plastic septic drain tile tubing) If anyone is interested, I can give further construction details for the "pancake" under floor heat storage."
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I can see how that would slow down air flow -- and cause more turbulence -- to maximize transfer of heat between air and sand. I'd like more construction details for the "pancake" system. I was encouraged to read about a similar heat storage system (many years ago -- most likely in MEN) where the original insulated mud slurry "heat storage battery" was allowed to dry out. They discovered the lack of moisture didn't significantly impact on the system's ability to store heat. I was kinda' surprised by that.
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sail4free
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