hoophouse cold at night
- Thread starter cave
- Start date
Hi Cave
Upgrading the covering to a double poly (inflated) would help. Other options are adding a metallized night curtain and suspending lightweight fleece over the plants.
The moisture on the inside of the poly is caused by the relatively humid air cooling to dewpoint when it hits the cold surface. As the air cools the RH increases to 100% the water then condenses out on the poly. It gives up a vast amount of energy in the process (latent heat) which is instantly lost through the glazing.
Inflated double poly helps keep the inside layer slightly warmer which makes it harder for the air to drop to dewpoint...generating less condensation
Upgrading the covering to a double poly (inflated) would help. Other options are adding a metallized night curtain and suspending lightweight fleece over the plants.
The moisture on the inside of the poly is caused by the relatively humid air cooling to dewpoint when it hits the cold surface. As the air cools the RH increases to 100% the water then condenses out on the poly. It gives up a vast amount of energy in the process (latent heat) which is instantly lost through the glazing.
Inflated double poly helps keep the inside layer slightly warmer which makes it harder for the air to drop to dewpoint...generating less condensation
Double 6-mil poly with inflation fan is the only way to go to get true "season extension" and reduce the rampant outbreak of the dreaded bud eating fungus.....
I also employ a small space heater to reduce drastic temp swings in October, heed the words of Me2's post.....
Hope things turn out ok for you!
I also employ a small space heater to reduce drastic temp swings in October, heed the words of Me2's post.....
Hope things turn out ok for you!
If you use any form of greenhouse heating, a radiant barrier made from mylar,reflectix or similar is a good investment. Clear night skies allow the greenhouse to radiate heat directly into outer space..its pretty cold out there.
After a clear night, it can actually feel warmer outside the greenhouse than inside due to radiant cooling
After a clear night, it can actually feel warmer outside the greenhouse than inside due to radiant cooling
Strike99
Member
yeah...a small blower.... you could try to seal and pressurize a layer.. but gl ...not worth your time at all..... wouldnt be very cost effective cause you generally have to replace the poly every 4-6 years.... you loose a little PAR but least they stay warm and cozy
Double poly uses two covers with a small blower to create a still air space between the two sheets. You get a couple of extra bonuses..the air pressure keeps the poly under tension so it doesn`t flap in the wind which will destroy it pretty fast and it will absorb gusts of wind.. a little like a car airbag in reverse..it cushions the hit and then instantly re-inflates
