Lars Lund

08 Sep 2020 14:34

Heat for the chilly nights

New heater for the greenhouse  

In the winter and spring 2012, I tested out different heaters in my greenhouse.

Juliana has 3 different sizes that fit 54, 108 and 161.5 square feet greenhouses. All are powered by petroleum. The petroleum heaters work the best early spring or autumn when the night frost isn’t that harsh. It is important to fill it with odourless petroleum or a quality lamp oil, otherwise, you risk melanising plants and windows. Petroleum incinerates oxygen which produces condensed water. Aeration is therefore important to bring fresh air into the greenhouse. The disadvantage of petroleum heaters is that they are not thematically controlled.


Finally, a warm front

Greenhouse owners have been looking for a heater with a thermostat for a long time. Some years ago, you could buy a small gas heater with a thermostat, but it disappeared from the market for unexplainable reasons. Maybe it was difficult to sell.

Times have changed. Now, when people don’t buy a greenhouse solely for the plants but also to chill inside, and the plants you buy need additional heat in the beginning and end of the season, you need heat and it needs to be adjustable. For that reason, I have been wondering why the supply has been so poor.



I am currently testing a gas heater with a thermostat. Preliminary I have used it for the chilly nights in April and start May. It works as expected and I enjoy the light from the gas nozzle when it works full throttle and then throttles down by itself. It is turned on by piezo, that is, an electric ignition without matches. First, you need to press and hold the button for gas and then the button for the spark. It’s a bit difficult on this model. It takes muscles and an awkward working posture. Also, you need to adjust the temperature from a drawn scale of a thick to thin line.

But what about the CO2? The bit that is released is absorbed by the plants in the greenhouse, so there is 0 emission.

A heater is not cheap, so save up for one.