..I think i’m on the right track for heating at night, nothing has froze yet.

but so far everything is trial and error.

Items Tried  in my 10×12 D.I.Y Green House:

2 Heat light’s – They do not heat a very large area, They might work for my 10×12 green house if I had 1 for Every Flat of 36 plants.

2 Electric heaters – They are 200-400 watt each, They Help and have keep everything inside from freezing, but outside gets too cold yet for them to keep the temp anything above 40 F
They Might keep the temp around 55-60 at night if I had 6 of them.

1 Propane 75,000 btu – Way 2 much, at any time and at any temp, set on Low it will bring the green house up to 90+ f within minutes.

So far I have not found a Nice way to heat, out side still gets way too cold for any kind of small heater, 1 month from now when nights are not as cold small heaters would do Fine.

I have a Few Idea’s I will try today, I think I will have A-lot better results.

UPDATE:  Here is a Idea decided to try.  2 Home-made  saw horses w/ 2 boards across them and one on top.

I will set the heaters in Under, and let down the plastic at Night.

And here is a Update I did to the green house, The wind was hard and I seen it was flexing my PVC pipe, So I added Side runner’s of PVC running from front to back on both sides.

UPDATED POST:

Update Mar 8th 2010 9:30 PM
Things Look GOOD.
As pictured above.

Temps

Outside: 26
Inside green house: 48
Under Plastic in green house: 55 !

I can Deal with 55, Tomorrow I will add plastic to the Ends to help hold more heat, I would believe if I did that it would be 60 F degrees.

And the Nice thing is no major Big Heater’s needed, just my 2 little 200w heaters under the flats and one heat light above. I’m starting to get happy to see things working out.

I took My Lazer heat Temp gun out to check the cement blocks, and Yes they are putting off a little heat, for how long, I’m not sure yet.

Here is a Update Picture:

A shot from my lazer temp gun to the flat soil, on the Far end next to the door away from the heat.

Update #3

ok, I was a little late but, 6:45 am Mar 9th 2010

Outside 17
inside 27
Under the plastic inside, 45

Nights should keep getting warmer, so I’m thinking I will let the 45f ride. 17 to 45 is a big difference, and after I cap off the ends with plastic, it should be better yet.