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Sizing a Greenhouse Heater

This calculator will help you decide on the size of heater needed for your greenhouse, based upon its size, your climate, the desired greenhouse temperature, and the greenhouse covering. 

First you need to know the total surface area of the structure:

Measure the five dimensions shown above.

  • Each end is A x C plus 1/2 A x E
  • Each side is B x C
  • Each half of the roof is B x D
  • Sum those values, then double it for the complete structure. Lean-tos will likely have only one end or side, and one roof slope.

Please note that this is an estimator only, and we offer no guarantee as to the reliability of these numbers. We recommend that you use this calculator for preliminary sizing work, and then consult a heating professional. Your orchid investment is worth the extra effort!