Model
| Roof
Vent | Side
Vent | Heavy
Vent | Windy
Site | | Sesam | Yes | No | No | No | | Univent | Yes | Yes | No | Yes | Bayliss
T.S. | Yes | Yes | No | Yes | | Hydraulicheck | Yes | Yes | No | Yes | Super
| Yes | No | Yes | No | Note:
All vent openers can be installed in series
to open a long or heavy vent.
|
Vent
Design
To avoid excessive temperatures
in the greenhouse, it is necessary to have enough
vents of adequate size. Ideally, roof vents should
equal 20% of the floor area, plus lower fresh air
intake vents equal to 10% of the floor area. Manual
opening and closing of vents is easily done, but
requires two trips to the greenhouse daily without
exception. One sunny day with vents closed and plants
look like last week’s salad or candidates for dried
flower arranging. A cold night with vents left open
will cause some plants to shiver to death and your
heating system may croak from exhaustion. (Or you
will croak when you get the heating bill!) So give
the plants (and yourself), the care and peace of
mind deserved – automate the vents!
Solar-Powered
Vent
Openers How
they work: The opener has a metal cylinder containing
a mineral wax which expands with heat. This pushes
a piston that opens the vent via a leveraged arm.
As the temperature cools, the wax shrinks and a
strong spring closes the vent and resets the piston.
Opening and closing are gradual adjustments, allowing
just the right amount of air flow for cooling. |
