Temperature outside got up to 50F, inside of greenhouse 86F at top then immediately dipped when clouds/trees covered the sun. How do I keep the heat in? It’s a wood 200sq ft greenhouse with polycarbonate roof and old windows with greenhouse plastic wrapped around windows. Doors are also sealed with greenhouse plastic to try and keep heat in. I’ve placed rocks within the greenhouse to try and collect some thermal mass. Anyone got any suggestions?
by Maleficent_You7040
4 Comments
That’s the neat part, you don’t! 😃
But really, you should size the ventilation to keep it below your max desired temp and roll from there.
A few big plastic barrels of water might help moderate the temp swings, or at least keep the min temps from dipping so low?
You need thermal mass. Basically objects that store the most amount of thermal energy (and release it slowly).
The best material for this is water. Barrels, buckets, whatever.
Following water, the next best materials are Concrete, Granite, limestone, brick, etc.
After that, soil works well too, especially if it’s moistened. If you have any empty planting beds in your greenhouse, fill them up with soil and water it. Or even stack up bags of soil, or sand bags.
And it’s best if this thermal mass is in direct sunlight.
Ventilation regulates the temperature if it gets too high and a heater if it gets too low. The sun isn’t consistent so treat it as a bit of strain relief for your main heat source.