the Otherpower.com Discussion Board || Comments Drainback to protect against overheating

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Rants & Opinion - Diaries - Our Products

Drainback to protect against overheating | 25 comments (25 topical, editorial)

Re: Drainback to protect against overheating (3.00 / 0) (#15)
by eliyahu (eliyahu@godspot.org) on Wed Dec 12th, 2007 at 11:26:26 PM MST
(User Info)

" A good CoP on the heat-pump might compensate for much of the relative inefficiency of PV compared to thermal for energy capture."

One thing I have heard from people who have used heat pumps in Ontario anyway is that the c.o.p. doesn't reflect the energy needed to extract the heat. In other words if the ground temperature is 54* fahrenheit or 11* Celsius the pump has to run almost continually to extract the heat. Whereas if the heat pump had a source of 70* heat then the pump wouldn't have to run as much.

What size and type of thermal mass are you using for heat storage?

What I am trying to implement is that I have a cistern in my basement that will hold about a 1,000 gallons of water furthermore the cistern is built with a large amount of rock around it as there is a stone foundation. Being an old farmhouse I can't insulate under the house so I have an infinite heat sink. My plan is to in late summer use ground in my greenhouse on the south side of the house to start storing heat in the 4 feet of ground below the floor of the greenhouse and into the stone foundation wall. The floor of the greenhouse will have r20 and the ground around the perimeter of the greenhouse I will insulate down 4 feet. What I hope to do is store heat with embedded water pipes in the 6"of concrete and air pipes 6" perforated drainage using a small solar powered fan to send the heat in the greenhouse down in to the ground to bring the temperature of the ground up 20* going into the fall so that it acts like a big flywheel.

You might be able to do something similar to shorten your winter needs as well.

I really like drainback systems because water is the best storage medium. There is no risk of poisoning yourself in the case of a leak. And since the water in the closed drainback system can be distilled then you don't have to worry about build up of calcium etc in your system. The energy requirement for the pump can be very small. Some people can actually get a thermosiphon working that of course would be sweet. But this demands that the water storage is higher than collectors. Another idea is to look at the Thomason house or Solaris idea for collecting heat. He used water running down the metal roofing under glass as the collector being stored in the basement but as was discovered by the 70's back to the land pioneers warm moist air can be a breeding ground for mold which is why water is king.

Where I am, I have to supplement with wood heat. I have a boiler that heats the house and outbuildings that I need when it gets below -10 celsius 22* fahrenheit. What I want to do though is that the boiler can be undertasked by this and so want to capture any other heat from the wood being burned and store it in the cistern which then acts as a preheat for domestic water. And my thermal heat sink.

Hope this helps

Of all the alternative energy systems on the planet solar thermal has to be king. Of course that is what the earth is a big heat sink.

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#16)
by DamonHD (d@hd.org) on Thu Dec 13th, 2007 at 01:03:22 AM MST
(User Info) http://www.earth.org.uk/

Hi,

Thanks!

I'm proposing a tank of up to 60,000l which would hold all our winter DHW/CH heat, though a mixed scheme might get away with 20,000l. And the surrounding soil would be good to use except that we might (I don't know) have relatively fast-moving groundwater not very far down from two nearby rivers.

http://www.earth.org.uk/milk-tanker-thermal-store.html

http://www.earth.org.uk/towards-a-LZC-home.html

My current house isn't really good for either scheme, unfortunately... So as we're looking to move anyway, it's an opportunity to find a more suitable location for RE too.

Rgds

Damon

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#17)
by eliyahu (eliyahu@godspot.org) on Fri Dec 14th, 2007 at 01:00:08 AM MST
(User Info)

Moving may prove to be best. Can you move to an apartment while you start from scratch and build? If you build an apartment can offer some life stability, especially since building is very stressful. Straw bale, tire houses and poured concrete forms sound really appealing from a design perspective. If you can build into the side of a hill then you've got thermal mass. Plan on a root cellar and passive solar greenhouse on south side. Buying raw land at least in my part of the world would save substantially in the long run. Though financing can be harder to secure.

A couple who live near me built a house out of tires. They were paid to take the tires and when they were done after 3-4 years of grueling work. They now have a house that will last that is warm in the winter and cool in the summer and NO mortgage.

Would be my plan if changing.

Looks like big economic storm is rolling in. They are trying to keep everybody happy spending while they look for assets that will escape massive depreciation. Reading the financial rags to see the roaring and tossing is mind boggling. This will keep the world wondering for quite a few years, and may provide a substantial melt-down in ability to access capital. Real-estate with big poorly built and insulated housing on it could depreciate dramatically. It sounds like that is now happening in the U.S. Looks like back to basics, as such houses that won't require a lot of external energy inputs will be smart.

There are housing developments in Alberta that have sunk large insulated storage tanks that use summer heat. Apparently they are working fabulously.

Hope this is helpful..

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#18)
by DamonHD (d@hd.org) on Fri Dec 14th, 2007 at 01:27:35 AM MST
(User Info) http://www.earth.org.uk/

Hi,

I earn most of my living from one of the big US investment banks (announced its results yesterday). Everyone was glum, since they did bonuses the same day, but no one's jumping off the roof. I expect a little more market turbulence, but I think my contract is safe for now for example, and we have money in the bank, and no debt other than our mortgage.

Anyway, that means that I need to stay within commuting distance of London, and even finding land to build on looks tough.

So we're looking for the best existing property we can: one bedroom more than we have now, a bigger garden (for playing in and burying a thermal store!), a nice place to live, good doctors and schools for our daughter (turned 2 today!), easy commute to London by public transport (possibly with the assistance of a small electric car), and of course a nice south facing unshaded aspect (eg on the roof) for solar thermal/PV...

Rgds

Damon

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#19)
by DamonHD (d@hd.org) on Fri Dec 14th, 2007 at 01:33:10 AM MST
(User Info) http://www.earth.org.uk/

Once recent development in the UK (and the rest of the EU) is that all houses for sale must show how energy-efficient they are) very soon, which will certainly be one of the aspects we'll be considering.

Rgds

Damon

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#20)
by eliyahu (eliyahu@godspot.org) on Sun Dec 16th, 2007 at 01:55:23 PM MST
(User Info)

Space is at a premium in Europe, frequent visitors to Canada from Europe have been known to make comments like they would see Halifax on Monday, Toronto, Montreal and Ottawa on tuesday and wednesday, Calgary on thursday and Vancouver for the weekend. I know from a short trip to France and the Netherlands that it took us 5 hours by train to go from Amsterdam to Paris. In Ontario 5 hour drive will get you from Ottawa to Toronto. It can take 3 days (8 hours) to get out of Ontario driving from Ottawa going west. I don't see cities as safe places. Most people are still convinced that they can pour toxic chemicals down the drain, coupled with a plethora of hormones and industrial solvents etc. So my inclination would be to get out of dodge. But that has it's costs and consequences. Adding a long commute doesn't seem wise. I would definitely want to be able to have a large garden and would choose land over building. How long would you have to drive to get out of London and hit country? Cheers

[ Parent ]

Re: Drainback to protect against overheating (3.00 / 0) (#21)
by DamonHD (d@hd.org) on Mon Dec 17th, 2007 at 01:26:04 AM MST
(User Info) http://www.earth.org.uk/

Very much depends what you call 'country' and 'London'!

From where I do most of my work in Canary Wharf over to the east of London, 30 miles or less could get you into relatively open space. It's certainly a line of investigation for me.

Rgds

Damon

[ Parent ]

Drainback to protect against overheating | 25 comments (25 topical, 0 editorial)

Menu

� create account
� How to use the board
� FAQs
� search the board
� Google search the board
� Old Otherpower Board

Login

Make a new account

Username:

Password:

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest � 2003 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!