Greenhouses are a great way to extend your growing season. Because most greenhouses remain between 80 and 85 degrees Fahrenheit, crops can continue thriving throughout the colder winter months. Maintaining that temperature, however, involves installing a heating and cooling system—especially if you live in colder or darker climates. There are a variety of ways heat a greenhouse in winter, here are a few of the most efficient.
Four Ways to Heat a Greenhouse in Winter:
Natural Heating Systems
One of the more economical routes to take is to use natural methods of harnessing the sun’s power. Heating systems can be expensive, and that’s why many growers prefer to avoid installing them altogether. Instead, they rely on more creative methods of sun magnification. For instance, some growers use the warmth generated by their composting piles to heat their greenhouse.
Another way to employ natural heating systems is to gather the heat generated by the sun during the day, and then use it at night. There are several ways to do this but the most common is to store solar energy in thermal mass. To do this, stack 55-gallon water barrels in direct sunlight within your greenhouse. Throughout the day, the water will become warmed by the sunlight. At night when the temperatures cool, plants placed near the water barrels will benefit from their warmth.
Like many natural heating systems, these do better in mild climates, or at the very end of a growing season. For difficult weather conditions or year-round growth, you may need to install a gas or electric heating system.
Gas Heating Systems
Natural gas and propane heating systems are the most popular methods of heating a greenhouse in winter. Natural gas heaters are more limited in scope as they require a gas line to be run out to the greenhouse. It can also be more difficult to obtain. Propane heaters, on the other hand, can be set up without a hookup making them extremely effortless and efficient option.
In either case, gas heating systems work by installing several unit heaters throughout a facility. These systems use combustion to warm the air, and then use fans to spread that air through the greenhouse. One downside of using a gas system is that byproducts such as ethylene, sulfur, and dioxide can cause harm to your plants. Proper ventilation and air movement in this case are necessary.
Boiler Heating Systems
Boilers use wood, coal, or fuel oils to heat the interior of a greenhouse using hydronic heating. In other words, by building a fire within the boiler, that fire then heats a large tank of water. Once the water has reached the desired temperature, it circulates through a system of coils installed inside the greenhouse. Gardiners with smaller ranges prefer to use boilers for hot water heating, while those with larger ranges prefer to use them for steam heating.
Though installation of a boiler can be a large investment up front, the fuel options it can use are the least expensive of all fuel options. Wood, for example, is one of the most inexpensive fuel sources available for heating a greenhouse in winter. To heat a 20,000 square-foot greenhouse would require 20,000 gallons of fuel oil or 110 cords of hardwood during the growing season. Though the oil would cost around $35,000, the wood would only cost approximately $6,000. That’s a $29,000 difference.
Electric Heating Systems
Though gas and boiler heating systems work well for commercial greenhouses, electric heaters are a great option for smaller greenhouses. For hobbyists and homesteaders, electric heating systems provide an easy-to-install and inexpensive alternative to massive gas or boiler systems. They can be controlled via thermostat and bought from a number of traditional retailers. All you need is an outlet to plug into.
No matter how you decide to heat your greenhouse during the winter, we can help you keep that heat in. BTL Liners provides clear greenhouse covers that allow 80%-87% UV transfer. They are more economical, more durable, and more light efficient than glass, allowing your plants to remain at their ideal temperature all season long. Contact us for more information.