We built our 14’ x 40’ off-grid greenhouse late last year (see video) and ran into issues with ventilation. The small exhaust fan / intake vent that we installed on the ridge is just not enough to keep up with the 85+ degree days over the summer, even with the roll-up sides. At times the temps inside hovered around the 115-120 degree range.
We are currently working on plans for the spring and looking for some suggestions from the group. Couple things to keep in-mind:
1. We don’t have much energy to spare for large fans as we are 100% on solar power. Passive would be great or some kind of multi-staged approach maybe using multiple fans? Not sure if we should exchange the air or cool the air? We can support a single-phase 120v AC fan but anything larger than that will be tough.
2. We only visit the greenhouse on weekends right now. Watering is completely automated and we have 1200 gallons of rainwater. We thought about building a swamp cooler using the water? The water is collected from gutters on the outside of the greenhouse.
3. We have a lot of tech inside so we could use automation to control when fans turn on/off and get creative. The theory is that high ambient temperature means more sun which means more solar which results in more power available.
We also have shade clothe, but we are not up there during the week so it’s tough to put on/off on a hot day. Also, we have a lot of volatility in temperature, we see swings of 30-40 degrees at night sometimes.
Let us know what you think, open to anything and everything no matter how crazy. If you checkout our other videos you will see parts of the build as well. Thanks in advance!
by johnsaltarelli
1 Comment
Can you add a ridge vent with staged opening? This will draw a lot of heat out especially if you have roll up sides with staged opening.