Greenhouse Heaters, Many Styles To Choose From

Over the course of a day, temperatures inside a greenhouse can fluctuate dramatically. This is especially true at night when cold temperatures could damage plants. To maintain the proper temperature for optimal plant growth, a greenhouse heater is recommended.

Upon seeing the many options available for greenhouse heaters, knowing which one to choose can be a daunting task. By understanding the various types of heaters and their features, anyone can make an informed decision about the right greenhouse heater for his needs.


Electric Heaters: For smaller greenhouses, these types of greenhouse heaters are perfect. Electric heaters have the ability to maintain specific temperatures while not releasing fumes. Without fumes, there is no need for extra ventilation within the greenhouse.

Gas Heaters: These greenhouse heaters run on natural gas or gas canisters and are better suited for larger areas. Ventilation is important with this type of greenhouse heater since fumes are produced and need to be vented outside. When using a gas heater, it is important to place the heater in a secure and accessible location since it will require regular monitoring and maintenance.

Paraffin Heaters: These greenhouse heaters are the most primitive. Like gas heaters, paraffin heaters require fuel which eventually releases fumes meaning that proper ventilation is needed. These heaters also require the most maintenance of the heaters listed. Maintenance includes constant fueling and trimming of the wick. Paraffin heaters are perfect, however, as an emergency heater or for a light frost.

Mounting Greenhouse Heaters

Hanging Mount: With this method, greenhouse heaters are either attached to the ceiling or allowed to hang down. This method is beneficial because no floor space is used, but care should be taken to avoid the heater becoming an obstruction.

Wall Mount: Like it sounds, these types of greenhouse heaters connect directly to the wall and allow for ventilation to the outside of the greenhouse. Again, no floor space is needed, but the area in front of the heater should be clear.

Floor Mount: Floor mounted heaters can stand alone anywhere on the floor of the greenhouse to maximize efficiency. Obviously, one should not choose this type of heater if space is limited.

Heater Combustion

Open: Greenhouse heaters using this system have no contact with air outside the greenhouse. This system is appropriate as long as the air inside the greenhouse has no contaminates. Extreme care should be taken to assure that no flammable liquids are placed near the heater as the burner is not sealed.

Separated: This system, used by gas heaters, works by pulling air from outside the greenhouse for combustion. The exhaust is then released back outside the structure. The burner in this system is sealed to separate the air from outside and inside the greenhouse.

Sealed: Sealed systems are very similar to separated systems. The air used comes from outside the building, and the burner is completely sealed. The difference comes from the fact that sealed systems use a single direct vent for both exhaust and intake.

Heater Vents

Unvented: As the name implies, there are no true vents with this option. Any fumes produced by the heater will be released back into the greenhouse. This ventilation type should only be used temporarily as fumes can be harmful to many plants.

Gravity: Here the exhaust moves upward through a vertical pipe and is released outside the building. The main consideration for this type of vent is that exhaust pipes must go straight to the ceiling.

Power: This system works by forcibly pushing air through a series of pipes leading outside the greenhouse. Using a powered system allows for more flexibility in choosing an exit location and is more efficient through the use of smaller pipes.

Direct: This type of ventilation is used exclusively by sealed combustion systems. Direct ventilation works by using only one vent pipe. Inside the main pipe, however, are both the intake and exhaust pipes.

Aside from the four features mentioned above, anyone planning to install a greenhouse heater should also check the output range, which is a measure of the heat output. The desired number for the output range is determined by the size and shape of the greenhouse, and any local greenhouse supplier should be able to calculate the proper level.

Along with Greenhouse Heaters, there are many more accessories that are required to run an efficient Greenhouse. Check out Greenhouse Supplies