| Author | Message | ||
| Jimmci9 (209.240.205.68) Rating: N/A |
thinking about pre-heating the water before it goes into my electric 12 gallon water heater.... ive got the 'lectric on a timer.. it comes on at 4am.. for about an hour... and again at 2pm for about an hour....these times seem to work out with my water usage schedule....but i was wondering about pre-heating the water... using black flexible plastic pipe.... 3/4"... however much it takes to make about 12-15 gallons.... roof weight is not a problem.... and ive got the back 12' worth of roof to use.... i tried solar a long time ago, so i know about sealing the pipe in a box, with a plexiglass lid, etc....but is anybody doing this now???? and how much water does 3/4" pipe hold??? | ||
| TWO DOGS (65.179.193.67) Rating: N/A |
get a 100 foot roll...leave it rolled up no need to lay out a 'grid'...the black pipe gets so hot & builds up so much pressure,it will develope pin holes & need to be replaced EVERY year...it's cheap tho...&....would have to be removed before winter...I had 1000 feet on top of the ground once...all I could get out was steam....heres a hint.....Never mix concrete with hot water  ... | ||
| Adame (129.82.53.158) Rating: N/A |
pi x r squared x length (12") 3.1416 x .375 x .375 x 12"= 5.30145 cubic inches/ foot of tube gallon= 231 cubic inches 231cubic inches/5.301(per foot) = 43.5 feet of 3/4" tube per gallon. | ||
| Dale MC8 (66.81.131.206)
Rating: N/A |
You might want to rethink locating the pipe on the rear of the roof. It will have to be in the sun to work and that could make your bedroom too hot for comfort. I found this out by locating my PV panels over the bedroom. FWIW Dale | ||
| DrivingMissLazy (66.168.175.51) Rating: N/A |
Jim, I think you might have a problem, as there is no way to turn the heat off. You would end up with steam and then a burst pipe. My experience. I used 500 feet of 3/4 inch black poly pipe on the roof of my house in California. Diverted a small amount of water from the filter to run thru the pipe. With a slow steady flow (sorry, never measured the gph) I would get a temperature rise of about 15-20 degrees on a hot spring day. The 40,000 gallon pool would rise from the mid 60's to the high 70's in about two weeks. Filter running about six hours a day in the late morning and afternoon. No cover on pool and no box or cover for the poly pipe. Just randomly strung across the west facing roof. Worked great. Now for the problem. If I shut the system down for a couple of hours for some reason, when I turned it back on, I got STEAM out of the pipe. I believe you would have the same problem if you do not have a continous flow of water and a large enough heat sink to absorb the heat. I could easily raise the temperature of my pool to the high 80's if I left the flow on. When I no longer needed heat, I just disconnected the inlet pipe and let the water all drain out. Richard | ||
| R.C.Bishop (128.123.221.135)
Rating: N/A |
Get a water heater with a heat exchanger (marine, for instance), connect inline with your engine coolant, and enjoy hot water when the trip is done,,,,,or underway. Works for us! RCB '64 Crown Supercoach (HWC) | ||
| Tim Brandt (Timb) (12.8.192.60)
Rating: N/A |
I'm with RC. I had the exchange type on our sailboat and as long we weren't docked for an extended amount of time I never had to use the electric side at all | ||
| Dale MC8 (69.19.173.227)
Rating: N/A |
Its not that hard to convert a regular RV water heater to a heat exchanger type. Just wrap a couple turns of copper tube around the tank or even simpler, get some BIG hose clamps and clamp a straight piece of copper pipe against the tank. Plumb it inline as per RC. HTH Dale | ||
| R.C.Bishop (128.123.221.142)
Rating: N/A |
If one would coil the copper around the exterior of an existing tank,,,,,then insulate it (from the outside, of course) it will keep the tank of H2O warm overnight. Would guess one could use spray foam. Temps might be a factor. Freedom 10 has a temperature shutoff valve to keep the contents from getting too hot. As I recall, it is set at 150 degrees. Need to have a bypass direct back to the coolant line in case the valve closes. Ours works like a charm. RCB '64 Crown Supercoach (HWC) | ||
| john wood (209.137.231.89) Rating: N/A |
A neat installation would be using pex and the same aluminum plates that are used for radiant floors. Paint aluminum black, fill system with glycol or methanol water water mix and run thru an indirect style water heater. This would allow you to not have to worry about freezing and with a 20 gallon indirect, you would have a goodly supply to feed into the RV style water heater to "top it up" temperature wise when needed. I thought of using a similar system to add additional cooling for the engine! I keep my rear furnace on as it heats my bay with the water tanks and allows me to take a longer shower as the feed water is warmer, usually about 60F |