Moderating unheated greenhouse temperture fluctuations?

15 years ago

Hello, I have recently built a small A-frame greenhouse to use to extend my growing season for greens/rootcrops. The house is not a marvel of engineering; it was built out of scrap lumber I had laying around and skinned in 6 mil polyethylene. I am only needing the structure to last one season, and then will be putting in something better, time permiting.

It is relatively well sealed, and in the daytime makes it up to 110f to 120f. A wee tad warm. At night, it seems to maintain about 4-5 degrees above the ambient outside air temperture. I can add vents, but at this point I'm thinking of cracking the door to vent some heat.

Here's my question. Does anyone here (with more hands-on greenhouse experience) think that it would be appropriate to crack the door (to varying degrees of openess according to the expected daytime temps) at maybe 7:00am before work, and close it again when I get home, around 6:00pm? It seems to me that this might be an attractive (cheap) solution to my temperture fluctuation issues. Any insights would be most appreciated-thanks in advance!

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Comments (4)

web4deb
15 years ago
I open/close my door every day when I leave/come home from work....weather permitting
hueytlatoani
Original Author
15 years ago
For the past two days I have been leaving the door halfway open, and the inside temp has been about 13 degrees above the daytime temp outside. So a bit over 90f. Not too shabby; I think that's a pretty good improvment.
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tsmith2579
15 years ago
Even in the winter time when nights get down into the 20s and days here go into the 50s, I will open my doors before leaving for work. Many times the temp may be 28 degrees but I open the front and back doors. As soon as the sun comes up it will hit my greenhouse broadside and hit it up quickly. On colder days, I will leave the doors open only a little so excessive heat can escape.
hueytlatoani
Original Author
15 years ago
Thanks for the info. I decided to try the same thing, leaving the door open in the day and closed at night. What I've noticed which I find interesting is that as the day/night temps go lower, the difference between indoor/outdoor temps widens. About a month ago, the temps were 4-5 degrees f warmer in the greenhouse (before morning light) whereas now they are around 7-10 degrees warmer. Last night it was officially 42f where I live, 40 from a thermometer on one side of my house, 38 at the peak of the greenhouse roof, and a whopping 48.7 at ground level in the planting beds. I'm thinking this may actually be a useful season extender! I've moved my largest papaya plant inside the greenhouse (until it gets really cold) in hopes that the higher daytime temps will healp it to ripen the crop of fruit it's holding before I have to move it into the house for the winter.

Moderating unheated greenhouse temperture fluctuations?

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web4deb

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Moderating unheated greenhouse temperture fluctuations?

Comments (4)

web4deb

hueytlatoaniOriginal Author

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tsmith2579

hueytlatoaniOriginal Author

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hueytlatoani
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