Solar Heating of Hot Water - advice wanted

[jpiette]

I am a new member and have been reading many postings on a variety of topics. There are many people who know a bunch about solar heating. I guess I’ll just plunge right in with my situation and see what unfolds.

We (family of 5) live in the northeast region (aka Northeast Kingdom) of Vermont. At present, we heat our house (2800 sq. ft.) with a Central Boiler 5036 outside wood boiler. The hot water from the outside boiler passes through a Brazed Plated Heat Exchanger (13.43 sq. ft. – heat transfer area). We have a Carrier Propane boiler as backup. We do not run our outside boiler from May to late September. We heat our hot water in those months with our Carrier propane boiler. We have a SuperStor (SS-40) Indirect Fired Hot Water Stainless Steel Tank.

What my wife and I are looking for is a way to take advantage of the solar energy that passes over our house everyday during the months the outside boiler is not running. Our house faces west, however, our wood shed faces due south with day-long sun exposure. We estimate that we spend $500-600 in propane a year to heat our hot water during the 4-5 months the outside boiler is down. So what should we do?

Questions:
1. Is it possible to configure a system where the outside boiler and solar collector can work in tandem, thereby reducing the amount of wood burned?
2. Is it possible to tie in a solar collector into the existing heat exchanger used by the outside boiler?
3. Is it possible to have a solar powered pump to move the hot water through the heat exchanger? (if needed)
4. Is it possible to tie in a solar collector into our existing hot water tank without an auxiliary tank?

I may not even be asking the right questions. Any educational input would be greatly appreciated.

 

[mikeyny]

Here is what I have. Different situation. Heat and hot water with tarm boiler in winter. I have a stand alone nat. gas 40 gal hot water heater for the summer months. I also have a home made solar collector. (fairly easy to build). Just a 5 ft by 5 ft box with insulated back and sides. 2 1 inch copper header pipes with 1/2 inch risers between them. I used epdm roofing rubber I had and lined the inside back of the box and covered the pipes. I have a single pane picture window glass covering it. It sits on my flat porch roof at an angle to the sun. I have another 50 gal storage tank next to the Nat gas tank. A cheap used taco pump pumps the water up thru pex pipe to the panel and back to the tank. No sensor, nothing fancy. The pump is run by a simple plug in timer from 9 to 6 every day. this entire set up was made out of junk or cheaply acquired. parts. Family of 7. My gas bill went from 125 a month to 22. The payback was quick. The only funny thing about it is the way it looks. My neighbor is still wondering why his old picture window is leaning up on the side of my porch roof though. No doubt there are better ways to do it, but this works for me. I simply drain it in the winter and turn a few valves to isolate it from the rest of the system. You can also go to builditsolar.com for ideas. Gary is very crafty.
mike

 

[Wallyworld]

Questions:
1. Is it possible to configure a system where the outside boiler and solar collector can work in tandem, thereby reducing the amount of wood burned?
2. Is it possible to tie in a solar collector into the existing heat exchanger used by the outside boiler?
3. Is it possible to have a solar powered pump to move the hot water through the heat exchanger? (if needed)
4. Is it possible to tie in a solar collector into our existing hot water tank without an auxiliary tank?

I may not even be asking the right questions. Any educational input would be greatly appreciated.

I'd go to www.builditsolar.com for some ideas. I'd also think about a heat pump hot water heater instead of solar depending on your domestic hot water needs.

I have a drainback system, works great, 2 3 by 8 collectors, soft tank, differential controller, heat exchanger in the tank, electric resistance back up. Been running for almost 20 years with little maintenance. Not sure what the payback is though. I bought a heat pump for back up and saw 30 bucks the first month. Now I run it all year round as backup, throw a few more sticks in the woodstove to get my hot water in the winter.

 

[begreen]

Contact WES099, he has a work in progress with some nice metering and documentation.

https://www.hearth.com/econtent/index.php/forums/viewthread/56372/