Our passive greenhouse solar water heater

It can’t get much simpler:

An old window framed with old 2 x 4s, an old piece of OSB for the backing, 20′ of 3/8 cooper, 3/8 and 1/2″ plastic tubing, a piece of garden hose and a couple of 1/2″ plastic barbs reducing to 3/8″.  Black spray paint for the OSB and copper and of course you need a water barrel.

1/5/10 solar water heater

This isn’t nearly enough copper tubing to actually get the water in the barrel “warm” in winter with freezing temperatures. However, it helps make the water a little warmer and this really was an experiment to see whether it would even work without a pump.
We originally planned on using an old water heater, but couldn’t get any of the upper plugs open. Ultimately, we want to preheat the water going into our propane water heater.

Why is the panel INSIDE?

An obvious disadvantage of the solar panel inside is that you get less sunshine for your plants. However, if we’d had more sliding glass door panels and time, we would have built a greenhouse with much more glass.

The advantage of having the panel INSIDE is that it didn’t freeze until it got down to 9 degrees the second night in a row. If you leave a solar water panel outside during freezing temps you either have to build a drainback system (no water in the panel when it freezes) or use antifreeze. We wanted to keep it simple.

ANOTHER advantage of keeping the panel inside is that the heat doesn’t dissipate outside (you can barely touch the glass when it’s sunny) and it helps heat the greenhouse.  The panel and copper of course also get warmer inside.
In spring that will no longer be desirable because it will get too hot during the day.  But it’s extremely easy to move the panel outside right in front of the barrel, just have to drill a hole for the garden hose into the plastic.

Construction:  SIMPLICITY rules
Continue reading “Our passive greenhouse solar water heater”

Our carport shadehouse converted to greenhouse

Last spring we cleared a foreclosed lot and got to keep just about everything there:   barbed wire, stakes, t-posts, fencing, bbqs, a huge metal framed sign,  linseed oil and just so much “stuff”.   We had a huge load for the dump and still have tons of metal and buckets of fittings and bolts.
Among the “stuff” were pipes and connectors for a carport.  As dust devils blew across the lot frequently and our little tomato cage (about 5 x 8′) was overflowing, we finally assembled what we had and realized that we were missing a few pieces.
We set it up as a 14 x 14′ structure with a flat roof, high enough to walk inside without bumping your head.

8/20/10 shadehouse

We had the rigid plastic for the ends from my old porch roof, shade cloth and only had to buy a few 2 x 4’s.

It worked surprisingly well!  Too bad we didn’t set it up earlier.

Snakes liked it too: Continue reading “Our carport shadehouse converted to greenhouse”