Depends on the climate but in many places, you need evaporative cooling aka a swamp cooler to keep the greenhouse temperate in summer.
ackwards
I shoot to keep it under 120 deg. That when my plants really start suffering. That’s when I cover it in shade cloth, and bring in extra fans, spray water on the ground
HooplaJustice
Lol, buddy, the shade cloth goes on the outside.
That one change is going to help you a lot
FamiliarCustard3144
If you live in a dry climate I use misters that lower the temp 20 degrees.
1_BigDuckEnergy
Misting….. I have a mister mounted on a fan that turns on at peak heat. Drops temps by 15 degrees. If you live in a very humid climate it will not work as well
mehmilani
I installed a portable evaporative cooler outside my greenhouse and made a duct for it. It was meant to be a makeshift temporary solution which has lasted many years. Combined with 30% shade cloth, it manages to keep below 100 on most days of summer.
JayEll1969
The heat is coming in through the glass with the sun before it hits the shade cloth.
Move the shade cloth to be on top of the outside of greenhouse – it will stop the sun from reaching the glass so less heat gets through it.
Which of the fans are pushing the air out and which pulling it in?
Dayglow_Bob
As another said, evaporative coolers are great for greenhouse cooling. I’ve got a good size one and that coupled with active ventilation keeps my greenhouse within a few degrees of ambient or lower. The fans and cooler are all run off a temperature controller to lock on when needed.
Novogobo
no, you’re just bad at it. that shade absorbs sunlight and produces heat, and you’ve got it on the inside. so you’re turning sunlight into heat inside your greenhouse.
pistil-whip
Admittedly I do not live in a hot place (Ontario, Canada), but I just keep the greenhouse doors open during the day and close them at night so the local wildlife doesn’t party in there and the hottest it gets is about 110. I have roof vents with those wax piston things that open and close with the temp. It’s often too humid for misting to help, but it has worked in a pinch as long as I use water from the house (which is cold) and not my water barrels.
av_clubmaster
On a different note, I used that same thermometer attached to our tree out the window. Ended up ripping it off because it was insanely inaccurate. I noticed because it read 100+ on 60-70 degree days. Might start there since it’s cheap and easy.
TheAstraeus
Might need more fans too. I have an 11×10 sunroom I use and have 4 box fans, make sure you have your currents set. Like where the air gets sucked in and where it gets expelled
AlexHoneyBee
It’s the greenhouse effect
milliemoo_22
Where are you located? I’m in northeast Texas, and it’s been a struggle. This is my first summer with a greenhouse, but I’ve finally got it staying a few degrees below outside temps. I’ve got a 9’x14’ greenhouse with an 85% aluminet shade cloth on the roof, two box fans on either end (where the windows are) blowing outside air in, misters on the ceiling, and recently added a swamp cooler. The misters give me the greatest control over the temperature. I have them on a WiFi timer, always one minute on, then I change how many minutes they’re off (1-14 min) based on the greenhouse temp to keep it below 90 deg.
Fake_Answers
30% shade cloth over the top, exhaust fan high on one end and a evap cooler on the other both flow air the same direction. Every thirty minutes for 10 minutes run an overhead mister.
I’m outside Phoenix with 110°f tempsand 13% humidity outside. Our greenhouse stays 80 to 95 with humidity at 45% all day.
Our greenhouse is 10x26x11 for comparison. Still smallish.
Edit to add, the mister made the real difference, but all work together for the goal of cooling.
AKFrozenDude
On the outside…..This is the way.
LocomotiveMedical
In addition to some of the other great comments, you might need more air movement.
Leolily1221
You can try a shade cloth over the exterior of the greenhouse and open the ceiling if you can since heat rises . Cut the panels and make them hinged
PickleFricker
You’ve got the right idea but you’re missing some key details. One that others haven’t covered is that you’re using a fan and spraying water for cooling. That will only cool things down until the air is saturated (100% humidity), then it’ll start heatings things up slowly and you risk condensation. Get a small air cooler that uses a refrigerant if you want to actually make it colder more consistently.
19 Comments
Depends on the climate but in many places, you need evaporative cooling aka a swamp cooler to keep the greenhouse temperate in summer.
I shoot to keep it under 120 deg. That when my plants really start suffering. That’s when I cover it in shade cloth, and bring in extra fans, spray water on the ground
Lol, buddy, the shade cloth goes on the outside.
That one change is going to help you a lot
If you live in a dry climate I use misters that lower the temp 20 degrees.
Misting….. I have a mister mounted on a fan that turns on at peak heat. Drops temps by 15 degrees. If you live in a very humid climate it will not work as well
I installed a portable evaporative cooler outside my greenhouse and made a duct for it. It was meant to be a makeshift temporary solution which has lasted many years. Combined with 30% shade cloth, it manages to keep below 100 on most days of summer.
The heat is coming in through the glass with the sun before it hits the shade cloth.
Move the shade cloth to be on top of the outside of greenhouse – it will stop the sun from reaching the glass so less heat gets through it.
Which of the fans are pushing the air out and which pulling it in?
As another said, evaporative coolers are great for greenhouse cooling. I’ve got a good size one and that coupled with active ventilation keeps my greenhouse within a few degrees of ambient or lower. The fans and cooler are all run off a temperature controller to lock on when needed.
no, you’re just bad at it. that shade absorbs sunlight and produces heat, and you’ve got it on the inside. so you’re turning sunlight into heat inside your greenhouse.
Admittedly I do not live in a hot place (Ontario, Canada), but I just keep the greenhouse doors open during the day and close them at night so the local wildlife doesn’t party in there and the hottest it gets is about 110. I have roof vents with those wax piston things that open and close with the temp. It’s often too humid for misting to help, but it has worked in a pinch as long as I use water from the house (which is cold) and not my water barrels.
On a different note, I used that same thermometer attached to our tree out the window. Ended up ripping it off because it was insanely inaccurate. I noticed because it read 100+ on 60-70 degree days. Might start there since it’s cheap and easy.
Might need more fans too. I have an 11×10 sunroom I use and have 4 box fans, make sure you have your currents set. Like where the air gets sucked in and where it gets expelled
It’s the greenhouse effect
Where are you located? I’m in northeast Texas, and it’s been a struggle. This is my first summer with a greenhouse, but I’ve finally got it staying a few degrees below outside temps. I’ve got a 9’x14’ greenhouse with an 85% aluminet shade cloth on the roof, two box fans on either end (where the windows are) blowing outside air in, misters on the ceiling, and recently added a swamp cooler. The misters give me the greatest control over the temperature. I have them on a WiFi timer, always one minute on, then I change how many minutes they’re off (1-14 min) based on the greenhouse temp to keep it below 90 deg.
30% shade cloth over the top, exhaust fan high on one end and a evap cooler on the other both flow air the same direction. Every thirty minutes for 10 minutes run an overhead mister.
I’m outside Phoenix with 110°f tempsand 13% humidity outside. Our greenhouse stays 80 to 95 with humidity at 45% all day.
Our greenhouse is 10x26x11 for comparison. Still smallish.
Edit to add, the mister made the real difference, but all work together for the goal of cooling.
On the outside…..This is the way.
In addition to some of the other great comments, you might need more air movement.
You can try a shade cloth over the exterior of the greenhouse and open the ceiling if you can since heat rises . Cut the panels and make them hinged
You’ve got the right idea but you’re missing some key details. One that others haven’t covered is that you’re using a fan and spraying water for cooling. That will only cool things down until the air is saturated (100% humidity), then it’ll start heatings things up slowly and you risk condensation. Get a small air cooler that uses a refrigerant if you want to actually make it colder more consistently.