Calculate your greenhouse heating and cooling requirements

The purpose of a greenhouse is to maintain a stable climate for the plants growing within, and that typically requires the use of some additional heating in the winter and ventilation during the summer. Since HVAC systems are expensive (both to buy and to run), it’s best to find a solution that fits your specific greenhouse, saving money in the short and long term!

Here’s a bunch of greenhouse calculators to help you determine how big your greenhouse is and how big your heaters, coolers, vents, and fans need to be to keep your plants (and wallet!) happy.

Greenhouse Heating Calculator

Use this calculator to determine the “heat loss” of your greenhouse, measure in BTU. Then, choose a greenhouse heater that is rated at least 15-20% higher (to account for unusually cold nights – there’s always a few!). Check out some of our recommended heaters on the left!

Greenhouse Fan Calculator

The goal for greenhouse fans is to be able to circulate the entire volume of air inside the building within a minute. That much ventilation has a significant cooling effect and reduces a lot of the humidity that can make greenhouses unpleasant.

Exhaust fans typically have the best bang for your buck in terms of ventilation, but they’re not compatible with all types of greenhouses.

Greenhouse Fan Calculator

Evaporative coolers, or swamp coolers, are a great way to cool your greenhouse on a budget. Note that they can increase humidity in closed spaces like greenhouses, so having proper ventilation is important too!

If this calculator looks similar to the last one, that’s because it is 🙂