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+--- Thread: Homemade solar hot water (/showthread.php?tid=3487)
Homemade solar hot water - Punamom - 07-12-2008
O.k. Time to get industrious and save some money cause we need it for gas yah.
So the hell company is gonna feel the pinch finally at least from me.
I'm cutting the cord on the 40 gallon energy sucker.
So my idea is to get a few old 40 gallon energy suckers and strip them down to just the tank and paint them black put them in the sun (duh) and have them run through to the existing water heater (if it gets cold and rainy I can just turn the existing one on).
Least invasive so when my plumber comes back to finish the work he was paid for I can get the expensive permitted system.
Obviously this isn't the best system but I do everything myself and very cheaply (keep that in mind) whenever possible.
So I only use hot water for bathing up to 5 baths a day and washing dishes not much really.Doesn't have to be really hot.
Yes I tried turning the heater on once a day for a few hours and my bill went way up so thats not an option (for whatever reason I could not figure out).
My neighbor said to get 200 feet of black hose and hook it up but that seems a bit more expensive and troublesome.
3/4 horse pump
2 story house
2 1/2 baths
Heater and pump on ground floor
So any you guys think this will work????
Is there a better way???
What am I missing? I hope the system can handle.
RE: Homemade solar hot water - MarkP - 07-12-2008
I think it will work, as long as you practice whatever degree of conservation is necessary so that the solar heat can keep up. Many people fail at this critical step and are then disappointed, having unwittingly compared the solar system with the old conservation-be-damned system. In fact I think I have read of building solar water heaters in this way. You should build a simple glazed and insulated box to put the old water heaters in. I put one of those plastic bag campng solar showers in the back of my car once at the beach. Insulated from the wind, the water got scorchingly hot, too hot to use undiluted.
RE: Homemade solar hot water - Carey - 07-12-2008
Mark has a point, shelter your water tanks... We rented a house in HPP that had a electric water heater in an outside west facing closet.... we had forgotten that the breaker was 'OFF' on it for almost 3 days (sunny days) as every evening our showers were hot.... until a grey day... then we realized our error.... but we utilized that to our advantage on sunny streaks... breaker was switched & our west facing "solar closet" was put to work....
RE: Homemade solar hot water - Punamom - 07-12-2008
The insulated box part I was hoping to avoid... maybe I'll try it without and if it doesn't keep it hot enough I'll build that part later. anybody...
My neighbor tells me how he takes his shower with just the warm water sitting in the hose....
But hey I got a big family so....
I'm thinking somebody out there must have one of these systems.....
There are directions online but nothing specific to hawaii and stuff like our above ground pumps.
I don't want to waste time or money on things we don't need here etc..and I don't want to waste water cause its to hot and going out the overflow.
or worse yet cause damage to my existing system. So any advice would be very appreciated thanks
RE: Homemade solar hot water - DickWilson - 07-13-2008
Punamom; If your system is valved to allow a flow thru feed, convection heating should induce enough flow to circulate thru your hw storage tanks and thru the tubing, the only concern I would have would be whether the tubing would heat enough to generate enough head pressure to reach your roof if that is where you are putting your coil. You would need a bypass in the main hw supply line to allow flow thru the heating loop when there is no hw demand from the house. Cold water make-up will reduce your hw temperature rather dramaticaly at each use, but recovery should be fairly rapid with sufficient sunlight. Supply lines to and from the auxillary heating coil should be insulated to conserve water temp and minimize radiant heat loss. Residential TPR (temperature, pressure regulator) valves for home hw systems are rated at 150 psi for pressure and 210 deg. F for temp. I would not expect your system to exceed that and if it did, you would want the valve to vent the system to prevent damage or an explosion. Consult with your plumber for pump and pressure tank sizing to determine system static pressure.
dick wilson
RE: Homemade solar hot water - nanasohana - 07-13-2008
I think a simple but probably a great idea is to preheat the water going into the regular hot water heater with a simple black painted tank or coiled black hose. I bet it would make a big difference.
RE: Homemade solar hot water - DickWilson - 07-13-2008
Nancy; For most home owners your approach is probably the best, almost any other system that is built from scratch is going to require some tinkering and fine tuning and is going to take some degree of monitoring to keep it in tune, Sometimes I tend to forget that not everyone wants to tinker with their systems.[:I]
dick wilson
RE: Homemade solar hot water - DanielP - 07-13-2008
Nancy,
The tanks as collectors do not give enough surface area to collect the heat. A coil of 1/2-3/4" polypropylene pipe (cheap)laid in the sun will be the best collector of the heat.
The tank or tanks for storage. No need to strip them.
Now, here is the important part; if you can lay the coil (on the ground?)out BELOW the storage tank (in the attic?) and loop it with the tank outlet at the bottom and the tank inlet in the middle, the hot water will circulate by convection and the warmest water will collect in the tank. Do not forget to install a pressure relief valve at the tank hot water outlet to the house. You can hook up the tank (Electric water heater ) to the electricity for back-up heat.
I wish that I could draw a sketch for you. If you e-mail me, I could fax a sketch.
Dan
RE: Homemade solar hot water - macuu222 - 07-13-2008
"Yes I tried turning the heater on once a day for a few hours and my bill went way up so thats not an option (for whatever reason I could not figure out)."
Why is that? Anyone? It's happened to me also. I have the hot water heater on a 2 hour per day timer and my bill for the month was $20.00 more.....everything else being the same usage. Does the hot water heater use more energy to reheat the cooler water than if it was to be left on 24 hours?
RE: Homemade solar hot water - StillHope - 07-13-2008
I think the way to find out is to call your gas and electric company.
I don't know about HELCO,but our G&E company is usually very helpful to determine the reason of unusual extra cost on the bill.
Once my bill was higher for no apparent reason,no mistake in the meter reading.I call the SDGE and going step by step we came up with a possible problem,which later proved to be exactly the one.
It appears to be that on the old wall mounted thermostats for the AC even invisible move in the "off" switch(while dusting,for instance) can cause leak visible on the bill.So I went to the garage and turned the switch to the son of a bitch off for good.