This calculator will help you decide on the size of heater needed for your greenhouse, based upon your climate, desired greenhouse temperature, and the greenhouse covering. This calculator is designed for sizing a greenhouse heater, but it also works with other structures if you know the R- or U-factors.
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!