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!
Best Greenhouse Heaters by Output
1000 W / 3000 BTU Heaters
- STANLEY ST-300A-120 Electric Heater
- Infrared Portable Electric Heater with Thermostat
- iPower Electric Heater Fan
1500W / 5000 BTU Heaters
- Dr. Heater DR218-1500W Greenhouse Infrared Heater
- Bio Green Palma Greenhouse Heater incl. Digital Thermostat
- Ceramic Electric Space Heater with Adjustable Thermostat
3000W / 9000 BTU Heaters
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.
Best Greenhouse Fans by Form Factor
- HealSmart 24″ Heavy Duty Metal Industrial Drum Fan
- Lasko 20″ High Velocity Quick Mount
- Simple Deluxe 24 Inch Drum Fan 3 Speed
- Simple Deluxe 18″ Industrial Wall Mount Fan
- VES Moisture Resistant Outdoor Fan
- Hydrofarm Active Air Whisper Quiet Heavy Duty
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 🙂
Best Greenhouse Evaporative Coolers by Output
- Portacool Jetstream 220 Portable Evaporative Cooler
- Honeywell Fan & Humidifier with Detachable Tank
- Trustech Evaporative Bladeless Air Cooler