Heating: exposed to the elements

From hot water to steam centralized heating to fin radiation to furnace heating, there are many types of heating systems that serve various purposes in greenhouses. Maintaining and upgrading heating elements and fuel sources is one of the most important steps growers can take to ensure everything is running smoothly, says Dr. Nadia Sabeh, mechanical and agricultural engineer and founder and president of Dr. Greenhouse.

The heating elements and fuel within a greenhouse provide the basics of heating systems, and it is critical to make sure they are working properly and upgraded when necessary, Sabeh says. “In terms of the heating elements, which would be your boiler or your furnace, the biggest thing is efficiency — and not just efficiency for the sake of saving energy, but efficiency in terms of combustion efficiency,” she says.

If growers don’t have the right fuel-to-air ratio, they can produce harmful combustion byproducts, Sabeh says. If they are burning an overhead heater in their greenhouses but don’t have a high combustion efficiency, they are risking both staff and plants to ethylene and carbon monoxide exposure.

These harmful situations arise as heaters, electronics and valves age, Sabeh says. “Something comes from the factory and it’s brand new and everything’s calibrated to work out in your environment, and then over time, over wear and tear, overcycling — just overuse — those valves start to stick and there could be a kink in the line,” she says.

Sabeh also recommends that growers switch over from propane fuel to natural gas. “I know that a lot of growers are in rural areas or may not have access to utility-provided natural gas, but over time, as the natural gas network expands and utilities lay more pipe, sometimes an existing operation may come into access of natural gas,” she says. Natural gas burns cleaner, is cheaper and is a more efficient fuel than propane. It doesn’t usually have to be shipped, either.

Whether growers are heating air or water, they should make sure their heaters are running efficiently, Sabeh says. In addition to making the greenhouse safer, they are using less energy. “People use radiant heating, they use hot water, they use hot air — there’s a lot of different ways (to heat a greenhouse),” she says. “But, ultimately, it comes down to the heating elements, or that component that’s creating heat.”