Facebook Twitter LinkedIn YouTube
Order Toll Free  1-800-665-2124
Choose Your Country
United StatesCanada
View Cart / Checkout
Tell a Friend Bookmark this Page Small Font Medium Font Large Font Printer-Friendly Page

Greenhouse Heating

Selecting Your Greenhouse

Heating Your Greenhouse

HEATED GREENHOUSE ENVIRONMENTS

Greenhouse heating is an important issue to consider for your hobby or commercial greenhouse. The night temperature in a year-round greenhouse is the most important factor to determine which heating system is required. The greenhouse gardener also determines whether to winter over plants or to provide a constant growing environment.
 
Cool or frost free greenhouses maintain a night temperature of 40-45F (5-7C).This is suitable for frost sensitive plants and rooted cuttings
 
Warm greenhouse requires a night temperature of 55F (13C).Growlights are necessary for adequate light conditions in this environment.
 
Hothouse night temperatures are set at 65F (18C).This will provide a natural habitant for tropicals and exotic plants.
 
To calculate your greenhouse heating requirements: calculate the wall and roof space of your greenhouse by:
 
 (multiply the width of the greenhouse times the length of the greenhouse) x (the difference between coldest outdoor winter temperature and the desired night temperature) x 1.1
 
This will provide you with the number of BTU's required to heat your greenhouse.  For example, your greenhouse is 8 x 12.  The coldest outdoor temperature is 0 degrees F.  You want to keep the greenhouse at 65 degrees F at night. 
 
(8 x 12) x (65 - 0) x 1.1 = 6,864 BTU's
 
HEATING COSTS
  • Warm greenhouses can be twice the cost of a cool greenhouse.
  • Insulating the greenhouse can reduce the heating cost by 30% or more. To the inside of the greenhouse frame a clear 4 mill plastic liner is fastened with a clip. Then, airspace is created between the plastic and the greenhouse covering.
  • 16mm 5 wall polycarbonate is the most energy efficient glazing material available in today's greenhouse market.  With an R value of 3.03, it is 50% more efficient than insulated double glass, 10mm triple wall polycarbonate and 8mm 4 wall polycarbonate.  It is approximately 80% more efficient than 6mm or 8mm twin wall polycarbonate.

 

GREENHOUSE HEATING UNITS
  • Heating requirements depend on the size of the greenhouse, the night temperature required and the expected outside low temperature.
  • Electric heaters are the most common source of heat for a small greenhouse.

Greenhouse Heater

THERMOMETERS
  • The greenhouse gardener becomes very dependent on a maximum-minimum thermometer. This thermometer records the daytime high temperature and the overnight low temperature.
  • The thermometer readings will determine whether to adjust the heating thermostat.



Greenhouse Thermometer