How to Heat a Greenhouse: Four Ways to Keep your Greenhouse Warm

Do you love the satisfaction of fresh parsley and happy tomato plants from your own garden? Does the thought of getting dirt on your garden gloves and potting soil on your pants excite you? Those of us with a green thumb understand the frustration of winter time bringing its cold weather and lack of gardening opportunities. A greenhouse can be a lifesaver for a gardening guru, but maintaining a greenhouse in the cold months can be a challenge. Let’s discuss some of the best ways how to heat a greenhouse so you can be ready for any climate and weather!

How to Heat a Greenhouse with Solar Panels

Solar Panels are one of the best options for how to heat a greenhouse, especially if you want to be environmentally friendly and reduce your energy costs. (Who doesn’t want that?) Solar panels generate electricity from the sun, collect it and store it until it is converted with some type of external device. Without external devices like fans, water pumps, and heaters, you won’t be able to utilize solar energy.

Because the energy is stored externally, a solar greenhouse doesn’t need to rely fully on the sun. This means that on cloudy days the solar modules can still generate electricity. Below are some of the pros and cons of heating your greenhouse with solar panels.

PROS	CONS
Cost Reduction- Solar Panels cost more upfront but save you money in the long run.	Cost- Though solar energy is renewable, it does cost more upfront to install solar panels
Reliability– When set up well, solar panels work smoothly.	Weather dependent– Though solar energy is still collected on rainy/ cloudy days, the efficiency drops. Solar energy also cannot be collected at night.
No interruptions to worry about– Because solar greenhouses obtain their energy from the sun, there is no need to be concerned when there are power outages or interruptions.	Requires a lot of Space– Solar panels require a significant amount of space, especially if you want to produce more electricity.
Environmentally Friendly– Solar energy is a renewable, clean source of energy and will not pollute the environment	Panel Deterioration– Because of their extended time in the sun, solar panels can tend to break down and become damaged by ultraviolet radiation.

Steps to Heating a Greenhouse with Solar Panels

• Purchase a Solar Kit
• Determine where you want the solar panels
• Install the brackets, locks, and handles
• Connect all the panels and install them
• Complete your installation

Want to see how a passive solar greenhouse looks? Take a look at this video and see for yourself how a passive solar greenhouse works for heating!

How to Heat a Greenhouse with Water Barrels

Using solar to heat your greenhouse might seem complicated, so what if I told you that you could heat your greenhouse with water barrels? This method works well if you suddenly experience a cold snap and find yourself unprepared.

So how do you actually go about this? It really is quite simple. All you need is jugs of water and a sunny place to store them. Spray paint the jugs black, or better yet, use black jugs or barrels, and find a spot in the greenhouse that receives a lot of sunshine. The barrels will absorb the heat during the day and release it at night. Boom. There you have it. A warm greenhouse.

Another way to use water to keep your greenhouse warm is with a greenhouse water tank. Be warned that this will obviously take up more space, so you’ll want to plan accordingly. Here are some of the pros and cons of using water barrels to heat your greenhouse.

Pros	Cons
Low Cost– Aside from the storage containers for the water, there is little to no expense	Weather Dependant– This is not a good method if you have cloudy winters.
Flexible with Seasons– In the summer months, these jugs can be used to cool and regulate the temperature of the greenhouse.	Takes up Space– Naturally, the more water containers you have in your greenhouse, the less “grow” room you’ll have.
Good for Emergencies- If you find yourself in a sudden cold snap, this can come in handy	Lack of Precise Temperature Control- Not able to set to a specific temperature like a heater or fan

Steps to Heating your Greenhouse with Water Barrels-

• Multiply the square footage of the greenhouse by 2.5 to determine the number of gallons you will need to heat the greenhouse.
• Once you determine what size and how many barrels you need, paint them black or cover them with black trash bags.
• Place them in the sunniest spot in the greenhouse and fill them with water.
• Arrange your plants so that the plants that need more heat are closer to the barrels and the plants that don’t need as much heat are farther away.

How to Heat a Greenhouse with Electrical Heaters

There are surprisingly a lot of methods on how to heat a greenhouse, but one of the most popular ones is with electrical heaters. Electric heaters often come with a built-in thermostat so you can regulate the temperature and set it where you need to.

Set up a heater where you need it, and only run it when you need it. Keep in mind, of course, that you will need some kind of power outlet available. At the end of the day, an electrical heater may be one of the simplest and easiest ways to heat your greenhouse.

Here are some of the pros and cons of heating your greenhouse with electric heaters:

Pros	Cons
Simple and Easy to Run- It really is as simple as plugging it in and turning it on	May need several heaters- Because air is difficult to heat, one heater will probably not be enough to effectively keep your greenhouse warm.
Temperature Adjustable– Usually built with a knob so you can adjust the temperature.	Fire Hazard- Though it’s rare, space heaters can be fire hazards.
Non-Toxic- Unlike gas heaters, electric heaters will not emit any fumes.	May require extra set up– Installing electrical wires may be an issue if do not have them already in the greenhouse.
Does not need to be refilled	Will not work during a power outage
	May increase monthly electric bill

Steps to Heating your Greenhouse with Electric Heaters-

• Find and buy the heater you want for your greenhouse
• Place your heater in an open spot at one end of the greenhouse.
• Be sure to protect plants in close proximity by angling the heater over them.
• Set the thermostat to your desired temperature and turn on the heater.

How to Heat a Greenhouse with an Underground Heat Exchanger

One very effective method to heat your solar greenhouse is with an underground heat exchanger, also known as a ground-coupled heat exchanger. This method utilizes geothermal energy, which is quickly becoming a popular resource all over the world. Because the earth maintains a regular temperature of about 50-60 degrees underground (several meters deep, that is, it will get hotter if you go deeper than that), utilizing it to regulate the temperature above ground really just makes sense.

So why would you buy an underground heat exchanger with all the other methods of heating a greenhouse available?

Let’s see for ourselves

Pros	Cons
Saves on heating and cooling cost significantly	Expensive costs upfront
Environmentally friendly and reduces your carbon footprint	Doesn’t work well in sandy soil
Easy to maintain	May require more space than other heating methods
Improves air quality by removing harmful pollutants.

At the end of the day, installing an underground heat exchanger is a lot of work and probably sounds overwhelming to you. That being said, there are many benefits of installing a ground-coupled heat exchanger. Geothermal heat is actually very affordable to run on a daily basis, is low maintenance, and is quite simple to operate.

Understandably, installing an underground heat exchanger system is not high on anyone’s to-do list, but Hometown Structures offers an optional underground heat exchanger. It’s an excellent way for your greenhouse to become passive solar! Check out our underground heat exchanger and discover a great way to keep your greenhouse cozy and warm in the chilly winter months.

How to Heat a Greenhouse with Hometown Structures

It can be complicated to decide how to heat a greenhouse. With all the options and suggestions out there, how are you going to decide what’s best for your greenhouse and the well-being of your plants?

At Hometown Structures, we not only offer an environmentally friendly and easily maintainable heating method for your greenhouse, but we also sell, (wait for it), greenhouses! We offer solar greenhouses and garden shed greenhouses, and with customizable options available like a variety of window choices and venting options, you can make your greenhouse truly your own. Save your plants and finally get the greenhouse of your dreams! With our underground heat exchanger, you can be confident that your plants are staying warm, (or cool in the summer months), and you can be assured that you are doing your part in helping the environment.