Beat the Frost: A Comprehensive Guide to Greenhouse Heating Systems

A series of best greenhouse heaters are available, varying in the way they manufacture heat and either the type of fuel they require or their energy efficiency.

It’s one of the most environmentally sound types of greenhouse heating systems, and it’s also much less expensive. To best capture the sun’s heat, the greenhouse should have a south-facing pitch. You could also paint a whole north wall of the greenhouse black to better capture the sun’s heat, insulating a greenhouse for cold weather. Remember, warm air rises, so you also want to have a covering for over the greenhouse or shade cloth if you’re using it, that will pull down when the sun goes down. This will help trap the sun’s heat inside the greenhouse as best it can at night, maintaining greenhouse temperatures in winter and fall. Keep plants in the pots moist when using this method of heating.

The most common types of active solar systems used in greenhouses are air-based systems equipped with plastic screens, tubes, or panel loops, and water-based systems that transfer heat to barrels of water or rock beds. A solar collector that is located halfway down the side of the greenhouse allows the falling air to be cooler than an air-based collector located on the greenhouse’s roof. While the initial expenditure associated with the installation of solar panels might appear steep upon first examination, the prospect of considerable savings over time transforms it into a prudent investment worth thorough consideration. As energy costs decrease over time, the panels can eventually offset their initial expense.

Geothermal resources can be a significant source of heat for greenhouses. There are potential savings for greenhouse operators that are near geologic heat in the form of geysers, springs, or rising methane. Geothermal energy replaces traditional energy technologies and offsets the burning of wood and peat, which helps reduce the amount of carbon that goes into the air. Carbon regulation and incentives could make greenhouses that use geothermal energy more attractive.

The initial expenditure for geothermal heating systems can be considerable due to the expenses associated with excavation and installation. Nevertheless, the ongoing operational costs are low, and after installation, these systems typically demand very little to no maintenance.

Forced air heating is many degrees better than passive solar methods and even a few better than other heating methods. The best unit type for heat delivery is the typical tube of hot air. Forced air heating works best if you have a polyethylene-covered greenhouse. The heat moves quickly, and there is plenty of it because the vast majority of the light waves from the sun are allowed to travel through the plastic.

The downside is that forced air heating can consume more fuel than hydronic heating, and if the gases produced by the heating are not effectively expelled, they can lead to health problems for plants and people. One solution to prevent these problems is to install simple greenhouse ventilation systems.

The infrared heating system constitutes a form of heating characterized by high intensity, preventing frost damage in greenhouses. Infrared has strong directivity, rapid temperature rise, and no heat loss in space, which can directly meet the needs of crops for different temperature zones. This method of using radiation to transmit heat rather than directly heating the surrounding air in the greenhouse proactively emits heat, which quickly eliminates heat loss from the walls and sprayed water.

Bubble wrap insulation has been selected for greenhouse coverings for insulation when growers aim at protecting plants from freezing in greenhouses. Growers can attach a bubble wrap sheet to the greenhouse frame either inside or outside, creating dead-air pockets. These dead-air pockets act as an insulation layer between the inside and outside of the greenhouse, reducing heat exchange and temperature fluctuation. Air temperature in a middle-of-the-winter greenhouse with bubble wrap insulation has been reported to be 15°C warmer or higher than the outside temperature, without a heat supply.

Bubble wrap offers a budget-friendly and straightforward installation option for insulation, but it also has certain drawbacks. Prolonged exposure to UV rays can deteriorate the material, leading to a decrease in its effectiveness. Furthermore, although it permits light to penetrate, the intensity may be diminished, potentially impacting plant health.

One of the oldest and most reliable methods of winter and fall greenhouse preparation is compost heating. This way of heating a greenhouse is used to encourage the growth of heat-loving plants all year round. Air is heated up by microflora, and heat is distributed among the premises with the help of pipes. A compost heap is made of horse manure with bedstraw, night soil, and plant compost.

Microorganisms, being activated from the stage of heating, generate heat together with metabolic processes. Regular turning over of the heap, which is necessary for maintaining the balance of thermal modes of the composting process and for oxygen supply to microflora, slows down the heating process. The efficiency of such heating is low if you don’t shade the area for composting. The rest of the organic matter can be added to the compost heap.

Gas heaters are a great choice for larger commercial greenhouses or for those located where supplies of natural gas and propane are both cheaper and more abundant than grid electricity. One of the favorite advantages of these greenhouse safety heaters is that they are very efficient and they can make use of the lost heat created since their smokestack incorporates the heat directly into your greenhouse, instead of letting it float away and be wasted.

These heaters can be wall-mounted or suspended, and they are great for larger commercial and hobby greenhouses. Suspended units are often preferred as they help to distribute heat more evenly throughout the growing space. Most models are typically available in either natural gas or propane, and a lot of units can be converted from one fuel to the other by simply changing the orifice. When evaluating this option, it is important to consider fuel expenses. Additionally, ensuring adequate ventilation is crucial while operating these heaters to avoid the accumulation of harmful gases.

Greenhouse heating systems can generally function for several years without any significant trouble, depending on how you use them and the materials involved. The most obvious advice for maintaining your heater and achieving greenhouse heat loss prevention is to clean it out. All the bits and pieces of dust, soil, or organic matter that get sucked inside and trapped against the burners or the igniter can lead it to stop functioning. Periodic checks on your fan belts and oiling the motors could help your heater function for a long time.

Keeping an eye on your thermostat or high-limit switch can help decrease your fuel consumption. These switches can rust and get stuck in the 'off' or the 'on' position, making you waste fuel or not allowing your heater to supply heat to your greenhouse. Checking the pumps, kept in top shape and properly oiled, can lengthen their lifetimes and improve the heat distribution. In addition, being meticulous about the exhaust system of your heating source when it works on gas is always a good idea.

You may need to experiment to determine the optimal combination of these methods to maintain a conducive environment for your plants. To enhance your success, it is advisable to maintain detailed records, continuously monitor the air and soil temperatures inside your greenhouse, and assess the health and growth of your plants as indicators of the effectiveness of your heating efforts.

👇Other topics you might care this cold season:

1. Tips to Strengthen A Quictent Greenhouse

2. 7 Tips Preparing Your Greenhouse for Hurricane Season

3. Protect Your Fall Garden with a Plastic Tunnel Greenhouse