When choosing the best gas greenhouse heater for a facility, a person should consider several things. The amount of air inside the facility, the average low winter temperature of the region, and the desired interior greenhouse temperature are basic considerations when choosing a greenhouse heater. Other considerations include the types of venting, the location of the heater, and the purpose of the heater. Gas heaters typically burn natural gas, propane or liquid petroleum gas (LP), or kerosene, and the most common are natural gas and LP gas.
Greenhouse heaters typically heat small hobby greenhouses and large commercial greenhouses. The size and type of heater is different for each. Small greenhouses generally do not have ducts to distribute the heat. Typically, small greenhouses have ceiling-mounted heaters or ones that stand on the floor. There are several hazards that small greenhouse heaters may present.
When choosing the best gas greenhouse heater, a buyer should learn what hazards may be presented. Unvented heaters are easy and inexpensive to install, but the exhaust gases may harm the plants and the workers. Some plants, such as white petunias and tomatoes, are very sensitive and show the effects in approximately one hour. Some of the human reactions include irritated eyes, headaches, and drowsiness. Another hazard may be accidental fire damage when a heater tips over or overheats nearby items.
There are many options when choosing a gas greenhouse heater, including whether to place the main unit indoors or outdoors. Outdoor heaters need ducts or pipes to carry the heat into the greenhouse. Experts suggest that indoor heaters draw combustion air from the outside and vent exhaust to the outside. Some greenhouse owners use both styles because each has advantages.
One combination that greenhouse owners choose is to use an outdoor boiler that circulates water through piping. This may be pipes in the flooring or pipes under the growing benches. The resulting radiant heat provides constant, gentle heat to the plants. Overhead heat, from indoor hanging heaters or duct work from an outdoor heater, efficiently heats the air. Some owners place hot water pipes along the walls and ceiling, especially in areas where snowfall is common.
Choosing an efficient gas greenhouse heater is sometimes confusing. A buyer should ask the sales personnel to disclose the actual working efficiency of their product. A unit advertised as 100-percent fuel-efficient heater may be only 80 to 90 percent efficient in a greenhouse setting. A reputable company will normally disclose the average fuel efficiency numbers. To attain the highest fuel efficiency, typically an owner needs to have a gas greenhouse heater adjusted by qualified technicians several times a year.
Other features that most greenhouse owners look for are power venting, spark ignition, and a rust-resistant heat exchange chamber. The ability to turn on a heater's fan without using the heat is very practical during the warmer months or for air circulation. Duct work is expensive to install, so therefore many people choose a gas greenhouse heater that they can later upgrade to accommodate ducts. Many gardeners protect their plants from the stress of excessive temperatures by selecting gas heaters that have rapid heat recuperation time.