[Greenbuilding] A Solar Hot Tub

[Kathy Cochran]

Thanks for all your comments.  What I perhaps failed to mention is that where I live there are LOTS of very interesting slate and quartz rocks that could be repositioned and utilized to build the outside wall of the hot tub.  I am interested in how to make this structurally sound  -  for instance, do I need to start this 2 feet below ground level, and support it with rebar?  Or should I use concrete blocks and only SURFACE the outside with native rock?  What materials should I be thinking of using for insulation  ..... I have a lot of sheeps wool in the garage that I haven't had time to spin yet.  How would this work?  Then, I imagine that I would line it with concrete and paint it black or dark blue-green to absorb the sun.  Mexican tiles around the rim.

I really like the idea of a used PV panel for heat, because the logistics of placing it below the tub would work great, due to the hill dropping off so quickly.

Any suggestions would be MOST appreciated.  This project is "on a budget" which is sort of why I want to build it with the native rocks. A "Green" tub, as it were.

Thanks in advance,

Kathy


-----Original Message-----
>From: dantonioli at earthlink.net
>Sent: Jul 9, 2007 10:39 AM
>To: kathys_old_house at onemain.com, 'Greenbuilding Building' <GREENBUILDING at LISTSERV.REPP.ORG>
>Subject: RE: [Greenbuilding] A Solar Hot Tub
>
>Hi Kathy,
>
>Heating a hot with solar is easy! If you're on a hill and position the panel
>below the tub you might even be able to get a thermosyphon effect and
>eliminate the pump altogether. Home Power magazine has an excellent article
>on solar heating a hot tub. 
>
>One thing you should consider is to not use a typical black plastic pool
>panel because in the winter time it simply won't get hot enought to heat the
>tub. A used flat panel collector would be a great way to go. 
>
>Another option is to install a pv system for your home and size it to
>include the hot tub electric heater load. I just visited a co-housing
>development in Oakland and that's exactly what they did to eliminate the
>extra plumbing. Their hot tub is fully solar heated and they're still
>generating excess energy for the grid. It's not a bad way to go if you can
>afford a grid-tied pv system.
>
>Dan Antonioli
>
>
> 
>
>-----Original Message-----
>From: greenbuilding-bounces at listserv.repp.org
>[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Kathy Cochran
>Sent: Sunday, July 08, 2007 4:00 PM
>To: greenbuilding at listserv.repp.org
>Subject: [Greenbuilding] A Solar Hot Tub
>
>I am re-sending this out under a better Subject title  -  before it was
>under "adobe mix".
>
>
>> [Original Message]
>> From: Kathy Cochran <kathys_old_house at onemain.com>
>> To: <greenbuilding at listserv.repp.org>
>> Date: 7/5/2007 10:30:50 PM
>> Subject: RE: [Greenbuilding] Adobe mix
>>
>> Hi  All.........
>>
>> I live in Northern CA (Calaveras County in the Gold Country) with a
>beautiful south-facing hill below where eventually I will be putting a deck
>out to see the view.  I have been conjuring up building a hot tub into the
>side of the hill looking south to the view, where I could put a drain into
>the bottom and it would simply irrigate the pasture below.  Shoud I build it
>out of native rock and then LINE it with concrete, or do I need to use rebar
>to make a form?  I am open to any suggestions that any of your might have.
>I would like to heat it with solar and maybe run a circulating pump
>- don't know if I can do that with solar or not.  What is involved,
>cost-wise, to heat a hot-tub with SOLAR?  I don't want it to be large -
>enough for 2 people and a ledge for a glass of wine and maybe some built-in
>speakers.  Should I hire a backhoe to dig a deeper hole, or is the side of
>the hill, with quite a slope (about a 45 degree angle), all I need for the
>basic form?  Maybe I should build the basic form from the External IN, with
>rocks, then line with concrete, fill with water, turn on the pump and GO! 
>Any and all suggestions would be most welcome.  Thanks in
>advance.............Kathy in Calaveras County
>>
>>
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