Double Layer Greenhouse Inflation Question

5 years ago

last modified: 5 years ago

We just built our first greenhouse and there have been a lot of lesson learned along the way. It s a 21' x 18' PVC High Tunnel of my own design

with double 6mil film, and covering raised beds.

I just installed the blower (external air) and inflated the plastic. Found it to be too much pressure so I reduced it by both partially blocking the intake vent for the blower and just bought a switch to reduce the power to the blower motor. As you can see I have a little moisture between the layers that I also need to dry out.

This seems a little like blowing up a balloon. My plastic is very well sealed with wiggle wire and it seems to me like there's only so far you can blow up a balloon before it pops... Is a double layer greenhouse going to work the same way? Keep putting air in doesn't some need to spill off (or out)?

So on to the question...Do I need to install a relief vent? Such as a smaller hole on the opposite end? other wise how do you regulate the pressure? I have been looking at articles and videos about inflation but no one seems to address this. Am I worried about a non-problem here?

Any help or suggestions would be appreciated. BTW: this photo shows the greenhouse un-inflated.

Sort by:Oldest

Comments (5)

PRO
Advance Greenhouses
5 years ago
Jeffrey, Did you buy an appropriately sized inflation unit for your greenhouse? As you can see here, https://www.advancegreenhouses.com/poly-inflation-fan-kit/, we carry 2 different sizes (CFM). Our 60 CFM is for greenhouses up to 2200 sq feet. Our 148 CFM are for larger greenhouses. If you have the appropriate size there is nothing else you should need to do to adapt it for use. Hope this helps! Tammy
Jeffrey Coney
Original Author
5 years ago
Yes I bought a blower that can be "dialed down" from 74 to to 28CFM. I'm just thinking that if I continue to blow air in... After it's inflated... the extra air blown in has to go somewhere right? Or doesn't it work like that?
Related Professionals
Columbia Landscape Architects & Landscape Designers · Enfield Custom Countertops · Rapid City Custom Countertops · Frederick Landscape Architects & Landscape Designers · Kahului Landscape Architects & Landscape Designers · Baltimore Landscape Contractors · Tulsa Landscape Contractors · Duluth Landscape Contractors · Idaho Falls Landscape Contractors · Portsmouth Architects & Building Designers · Longview Architects & Building Designers · Calgary Architects & Building Designers · Houma Landscape Contractors · Rutland Landscape Contractors · Twin Falls Landscape Contractors
PRO
Advance Greenhouses
5 years ago
Jeffrey, OK, I am going to confess that I had to ask one of the guys for an explanation on this. Here goes.

"The centrifugal fans used in these inflation kits allow the excess pressure to blow back through the intake of the fan shroud. Additionally, the 148CFM fans have an adjustable damper over the intake to control air output.

In reality, the double-poly is never sealed 100% and is prone to some degree of leakage in most cases. So over-inflation is very rarely an issue."

So, rest easy. This should not be a problem. Tammy
Jeffrey Coney
Original Author
5 years ago
Thank you for the answer, I appreciate it Tammy!
HU-787518518
3 years ago
Is it okay to set a timer for a fan having it on for 2 hours and off 2 hours to save electricity ir does it need to be on 100% of time?