Solar water heater (DIY)

C_HeathC_Heath Registered Users Posts: 23 ✭✭
There are a myriad of youtube videos on this. I am very interested in this but I want to know the longevity of it. Im a DIYer so building the box I can do, the tank I can do, running the lines I may have to have some help. Ive read up and dont quite understand how to run cutoff valves at the current water heater so incase I didnt want to use the solar, I could shut the valves off and use the heater inside. Maybe a few more videos and Ill get it. My present heater is 15 years old and Id like to cut that breaker to OFF! 8)
Its a 50 Gal and chews up 5000 watts!


Could anyone share any tips or pictures of their setups?

Thanks!

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Solar water heater (DIY)

    Good site for lots of this DIY solar thermal stuff including hot water is Build It Solar: http://www.builditsolar.com/

    Their water heating section: http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Solar water heater (DIY)

    And some more links here:

    Solar Shed and other Solar Thermal Links

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • LucManLucMan Solar Expert Posts: 223 ✭✭✭
    Re: Solar water heater (DIY)
    C_Heath wrote: »
    There are a myriad of youtube videos on this. I am very interested in this but I want to know the longevity of it. Im a DIYer so building the box I can do, the tank I can do, running the lines I may have to have some help. Ive read up and dont quite understand how to run cutoff valves at the current water heater so incase I didnt want to use the solar, I could shut the valves off and use the heater inside. Maybe a few more videos and Ill get it. My present heater is 15 years old and Id like to cut that breaker to OFF! 8)
    Its a 50 Gal and chews up 5000 watts!


    Could anyone share any tips or pictures of their setups?

    Thanks!

    *Do a search for a solar thermal drainback system. No antifreeze required.
    Buy a good quality 4 x 8 flat plate panel, (Made in the USA,they are good for 25 years) pipe it to a drain back tank with a heat exchanger or with out, depending on your storage tank.
  • solar_davesolar_dave Solar Expert Posts: 2,382 ✭✭✭✭
    Re: Solar water heater (DIY)

    Lots depends on your location. The simplest is just a loop no drain back but it is subject to freeze in those zones.
  • redwireredwire Registered Users Posts: 5
    Re: Solar water heater (DIY)

    I've been looking into this too. I don't like the idea of doing a lot of plumbing changes to the house.

    Then I googled solar hot water pv hybrid grid where one site says "100% Solar Electricity (PV) is now a better value than Solar Hot Water and Solar Electricity combined." another "It’s now cheaper to use a photovoltaic system to heat domestic hot water"
    http://www.greenbuildingadvisor.com/blogs/dept/musings/solar-thermal-dead

    They also mention how in winter a solar thermal system is mostly useless due to the cold, where PV likes the cold. And there is always the issue with freezing problems if not done right and monitored.

    They have these hybrid systems where there are pipes behind the PV panels and collect heat that way, but all that is non standard custom panels and I can't pick them up cheap like the 65c/W panels that are out there. Then you are back to piping and the winter problem.

    Some of them use a expensive heat pump systems, and that requires plumbing modifications too.

    Try googling, youtube search or ebay with keywords like solar hot water pv hybrid grid to see those systems and others.

    I saw a low cost hybrid grid/off grid system I am seriously considering that goes more direct and I only have to make a few wiring changes in the garage.

    Let us know what you find.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Solar water heater (DIY)

    I agree that it appears that using a heat pump water heater is probably at parity or better than solar thermal when you take into account the plumbing/maintenance/how much work you have to do on installation (panels on roof, insulated pipe back to storage tank, etc.).

    If you are in New York, you may have issues with a heat pump water heater--They do cool (and dehumidify) the area where they are installed. Some installers are finding they have to add ducting from the outside to bring air in/exhaust cold air out in colder climates.

    Check the operational specs of what ever heater you are looking at--But for many that I have taken a quick look at, they start losing efficiency at 55F and lower.

    Perhaps they will have a new generation like Mini-Split A/C / Heat Pump systems--Put the evaporator unit outside for those climates (the new mini-split heat pump systems are being used in climates with snow on the ground and still better than electric or oil heat--pretty amazing stuff).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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