[Greenbuilding] [BULK] Re: Baxi Luna question

[Drew A. Gillett, P.E.]

as i have posted before, my now nearly 30 yearold system has been running 500-700 kwh of backup electric per year.  it has supplied about 80% of our hot water for a family of 2-6 during that period.  it's still does biweekly laundry for my niece. 

it is 80 sq.ft of flat black thin copper  single fibreglass cover with 120 now 80 gallon tank with a separately metered 6kw element in the top 15 gallons of the tank.  it has been reported on numerous times.  the stuff works.  solar displaces fossil fuels with clean renewable energy at  a cost and maintenance that people can afford. 

small gas fired tank units are about the worst you can do.

freezing to death in the dark is not what it is about reuben.
  ----- Original Message ----- 
  From: Reuben Deumling 
  To: Drew A. Gillett, P.E. 
  Cc: Jefro ; Greenbuilder list 
  Sent: Wednesday, June 20, 2007 4:58 PM
  Subject: Re: [Greenbuilding] [BULK] Re: Baxi Luna question


  Instead, save a lot of capital, some operating costs, a lot of maintenance costs, and a hassle with overly complex solar water heating installations and use a small gas-fired (tank) water heater--if you can find one. 
  I'll repost my question to this list of ~five years ago: to anyone with a solar domestic water heating system backed up by fossil fuels (natural gas, propane, oil, or electricity)--how many therms, gallons, or kWh do you use in an average year? You of course need to have a submeter installed to know this number, and these are not common. And in the interest of full accounting you'd need to include the electricity to run the pumps and such if you have them. 
  I like the idea of solar water heating a lot, and some on this list have submitted designs for home-made simple systems I find delightful, and hope to try myself one day soon, but in the meantime most of us have or have experience with off-the-shelf solar arrays that can be difficult and expensive to keep in good order year in year out, and are not all that impressive when it comes to the fossil fuel consumption they were meant to offset. 
  I welcome being proven wrong.

  Reuben Deumling


  On 6/20/07, Drew A. Gillett, P.E. <deaneg at hotmail.com > wrote:
    don't waste your money on a tankless

    instead , save a lot of capital, some operating costs,  a lot of maintenance 
    costs,  and a hassle with poorly operating tankless units and simply install
    a backup electric heating element in the top of the solar tank and an extra
    collector with the money you save on not buying the useless tankless.