Greenhouse Heating in the cold

[Ray]

To all who have greenhouses,

I did a little test myself this weekend. I have a small green house, 8 feet wide, 15 feet long, and the roof is a 4 rise to 12 run pitch. This gives me enough for what I want. I was having trouble keeping the temp up with the little electric heater that I have. I didn't have the money for a propane heater nor did I want to invest in one this late in the season. So I thought if I could reduce the size of my greenhouse inside, I could increase the temperature. I couldn't reduce the width or the length, so I thought about the roof. I figured that was unused space anyway. So instead of messing with the structure, I simply stretched some thick visqueen from the top of the walls horizontally to the other walls. This reduced the amount of space by the amount that is now above the ceiling. On two identical 24 degree nights, my temperature rose by 12 degrees!

So, if you are having trouble with the temp in your green house, just put in a ceiling. It worked for me. If I am telling you something that you already know or if this is elementary to you, I'm sorry.

Hope it helps.

[Gene]

Ray I thought of the same thing but haven't done it . I thought if I could get my hands on a back hoe I could dig a trenck 3 foot wide by 3 foot dig the full length of the greenhouse in the center that is and have about a 7 foot high roof to the bottom of the trench. But I can't think of anything cheap to put on the sides of the trench so they don't cave in on me.

Bob I like your ideal 4 lightbulbs equals 400 watts per hour If you kept them on for 10 hours that would be 4000 watts or 4 kilowatts at 6 cents per kilowatt that would be 24 cents per day.

[Log Cabin Pat]

Hi
I have had to heat my 18x60 twice so far with kerosene heater. I turned it on when it got down to 10 the other night. I have hundreds of water filled milk jugs under the benches and as long as it stays in the 20s it stays just above freezing in the greenhouse. All of the plants I have in it are hardy but they are starting to put on tender new growth, so far so good. It is going to be in the high 60s the rest of this week then down in the 30s and 20s for next week. I guess this makes gardening interesting.

Pat

[sewfarsewgood]

I am in the process of storing water jugs and getting some water barrels. I want the 30 gallon plastic barrels that I can paint black, fill with water for heat storage, and use for supports for potting benches. I also want to save as many milk jugs etc as I can to use for addl water storage / heat storage. It will cut down on the propane usage, but isn't worth much after you have 4 or 5 days of cloudy weather, with a cold snap at the end of it.

I like the flexibility of the propane and it is even better since I have the capability to fill the 20 and 40 pound bottles here on my property.

The remote wireless thermometer with an alarm from Wally World is proving to be a godsend. Sure does prevent me from going out in the cold just to ensure the greenhouse is OK. Much easier to moniter it from my bedside.

Gary J

[Steve Wheat]

HI Gary
I would like to know more about the remote thermometer. I think I would like to get one of those. I had to keep a close eye on my propane bottle(40 # tank) when it gets low . This would be ideal for me. And save tons of worry that I will let my GH get to cold. If you don't mind could you tell me more about the thermometer. Specific name etc...don't want to pick up the wrong one at Wally World.
thanks a bunch
steve