Best Greenhouse Heater: Our Top Picks to Heat Your Greenhouse in 2022

greenhouse heater

Greenhouse heaters come in various shapes and sizes, making it difficult to determine which one is best for your greenhouse or grow tent. This article will explore the best greenhouse heaters and provide a comprehensive buyer’s guide to help you make the right decision for your needs.

You are currently doing so much research on how to get started. There is much more to it than you were initially expecting, especially when it comes to heating your space for a greenhouse.

Greenhouse heaters come in a variety of sizes and power sources. Conventional space radiators and electric fan heaters are popular when warming large greenhouses. With radiator heaters, convection transfers heat from the radiator to the air instead of heating the objects. However, that does not mean you cannot use other fan heaters either. 

In this article, we will be going over a lot of great information. First and foremost, it is essential to know what type of space heater is a good choice for your greenhouse and the importance of having a greenhouse heating system in the first place. 

11/10/2022 07:19 am GMT

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Best Electric Greenhouse Heaters

So now that we have gotten all of the general information, here are some great space heaters to warm up your greenhouse. 

Best for Large Greenhouses
Bio Green Electric 240V Heavy-Duty Heater
$299.99

The Bio Green Phoenix Electric Heater is perfect for larger greenhouses up to 180 square feet. With three output levels, the Phoenix provides temperature control between 32 and 79°F. The Phoenix Electric Heater is high-quality, rustproof steel with a quiet, powerful built-in fan for air and heat circulation.

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11/10/2022 07:19 am GMT

The Bio Green Heavy-Duty Electric Heater Fan will warm more space and has a 2-in-1 option to hang it to the ceiling or place the radiator on the floor. This could be very convenient for you, especially if you are trying to get it in a place that heats the entire area.

This heater has some built-in features, including frost detection functionality, a heating and cooling setting (for ventilation), and a quiet yet smooth running fan. This is the heater to get if you wish to have quiet and allow something powerful to run inside your greenhouse. 

The smooth running fan ensures quiet operation, while the IPX4 waterproofing protects against water spray. Additionally, the frost detection function kicks in when the temperature drops below a certain point, keeping your home safe and warm.

The Bio Green PHX 2.8/US Phoenix Electric Heater is perfect for both the cultivation of young plants and for protecting them during the winter months. With three output levels, the Phoenix provides the great output and easy temperature control between 32 and 79°F.

The Phoenix Electric Heater is high-quality, rustproof steel with a quiet, powerful built-in fan for air and heat circulation. Flexible, dependable, and easy to use, it can be operated on its own or in conjunction with the greenhouse heater and is perfect for keen gardeners who want to protect their plants from the cold.

Because this heater requires 220/240V power, you will need an extension cord plugged into a 220/240V outlet in the greenhouse.

Heats up to about 180 square feet.

Best for Small Greenhouses
Bio Green Basic Electric Fan Heater
$149.99 $96.99

The Bio Green Electric Fan Heater is high-quality and provides efficient heating and ventilation in greenhouses for optimal growing conditions all year round. This IPX4 waterproof heater features 1500 w/ 5118 BTU heating output. The heater is very energy efficient with a 2-year warranty.

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11/10/2022 04:19 am GMT

BioGreen Basic Electric Fan Heater for Greenhouses is a high-quality greenhouse heater that provides efficient heating and ventilation in greenhouses. The combination of the air circulation mode, which cools down the temperature in summer, and the heating mode ensures optimal growing season conditions all year round.

You can adjust the fan to low, medium, and high speeds. The highest speed reaches 460 m³/h (1,000 ft³/h) with a power consumption of 1 kW at 230 V.

This is the ideal choice for hobby greenhouses and other humid areas. This IPX4 splash-proofing heater features 1500 w/ 5118 BTU heating output. The heater is very energy efficient and engineered in Germany with a 2-year warranty.

Because this heater requires 220/240V power, you will need an extension cord plugged into a 220/240V or 220V/240V outlet in the greenhouse.

We recommend greenhouse owners pair the heaters with a digital thermostat such as the BioGreen Thermo 2 Digital Greenhouse Thermostat below.

Recommended Accessory
BioGreen Thermo 2 Digital Greenhouse Thermostat
$82.66

This digital greenhouse thermostat ranges from -50 to 108 F and has a digital display that shows the actual and set temperature in Fahrenheit or Celsius. The thermostat also includes an external temperature sensor for measuring the ambient temperature. It has a 2-year warranty.

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11/10/2022 02:09 am GMT

The BioGreen Thermo 2 Digital Greenhouse Thermostat is perfect for controlling your Bio Green heater, heat mats, and heating cables in your greenhouse. The thermostat has a range of -50 to 108 F and a digital display that shows the actual and set temperature in Fahrenheit or Celsius.

The thermostat also includes an external temperature sensor for measuring the ambient temperature. It comes with a US plug and a 2-year warranty.

Best Solar Greenhouse Heaters

Solar greenhouse heaters are an environmentally friendly way to heat a greenhouse and can save money on energy costs. Solar greenhouse heaters can supplement or replace traditional heating sources, such as natural gas or propane.

Solar greenhouse heaters are typically photovoltaic cells that convert solar energy into electricity. The electricity is then used to power an electric air heater or heat water circulating through the greenhouse.

Solar greenhouse heaters can maintain a steady temperature in a greenhouse or provide extra warmth during cold weather.

Renogy 100 Watt 12 Volt Solar Panel Starter Kit
$175.87 $165.99

This starter kit can use solar energy to power virtually any electric heater for your greenhouse.

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11/09/2022 05:19 pm GMT

Best Small Greenhouse Heaters

Small greenhouse heaters are perfect for small greenhouses or grow tents smaller than 100 square feet. Larger greenhouses should use a heater listed above or opt for a natural gas heater.

iPower Electric Heater for Greenhouse, Grow Tent, Spraywater proof
$84.99 $56.36

The iPower Electric Heater has a stainless steel housing with an enclosed fan motor that is IPX4 rated (waterproof) perfect for greenhouses, barns, and grow tents. It also includes overheat protection, discharge safety grills, and a stable anti-tip over design. Heats up to about 100sf.

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11/09/2022 10:14 pm GMT

iPower Electric Heater is yet another less expensive option. It can efficiently heat up to 160 square feet and is designed explicitly for outdoor usages, such as garages, workshops, offices, and greenhouses. This product comes with a 1-year warranty and is spray waterproof. 

Another excellent feature is that iPower is, once again, another heater that comes with overheating protection. However, it is suggested that if this is the case, you should unplug the heater to allow it to cool down for another 10 minutes until you restart, so make sure you find that sweet spot in the middle. 

On top of that, you will find that this heater has a powerful thermostat controller ranging from temperatures to -40 to 176 degrees Fahrenheit or Celsius, depending on your preference. 

The iPower Electric Heater is a powerful portable heater that can quickly heat small spaces. It has an adjustable heating range from -58°F to plus210.2°F (-50° C to plus 99 ° C).

The air output of this heater is 4500 Cubic Feet/ Hour, which will keep your room or greenhouse warm and comfortable. This heater uses 25W-1500W of power, depending on your chosen temperature setting.

The iPower Electric Heater can be used in greenhouses, barns, and grow tents.

iPower Electric Heater Fan for Greenhouse is explicitly made for wet environments like greenhouses! It features a stainless steel housing enclosed fan motor and is completely waterproof (IPX4 rated).

Another feature unique to this heater is that the fan runs continuously in heat mode providing optimal air circulation and heat distribution.

Other features include fan-only operation, overheat protection, discharge safety grills, and a stable anti-tip over design.

It comes with 7 Feet grounded power cord. Electric Supply 120V 60Hz. Heats up to about 100sf.

Most Portable
Dr. Heater 1500W Greenhouse Infrared Heater
$129.99 $106.51

Dr. Heater DR218 is a 1500-watt infrared heater with an IPX4 waterproof structure that is lightweight and portable. This unit works best in small grow tents or greenhouses less than 120 square feet.

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11/09/2022 07:29 pm GMT

Dr. Heater DR218 is a 1500-watt infrared heater with only one temperature setting. The IPX4 structure of this greenhouse heater does not allow water splashing, so you can use it without worrying about getting it wet while watering plants.

It is easy to move from one room to another because it is lightweight and portable. This item has low maintenance needs and comes with an instruction manual that will teach you how to use the product.

This unit works best in small grow tents or greenhouses less than 120 square feet.

Best Radiator Space Heater for Greenhouse

Safest Space Heater - Top Pick
De'Longhi Full Room Radiant Heater
$159.00

The DeLonghi TRD40615E Radiant Heater provides 1500 watts of heating power. This heater is maintenance-free with a permanently-sealed oil reservoir, and its high-quality steel assembly ensures durability. You can customize your comfort with an adjustable thermostat and 3 heat settings.

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11/10/2022 05:04 pm GMT

De’Longhi Full Room Radiant Heater

The DeLonghi TRD40615E Full Room Radiant Heater is a great greenhouse heater. It has a large heating area to heat your greenhouse quickly and evenly.

The digital thermostat makes setting the temperature exactly how you want it easy, and the timer allows you to preset the heater to turn on or off automatically.

The safety features include an overheat protection system and a cool-to-the-touch housing, which make it safe to use in any environment. This heater is also quiet, meaning you can run it without disturbing your plants.

It also runs off 110volt and plugs into a standard wall outlet.

The downside to using a radiator heater inside a greenhouse is that they are not waterproof and shouldn’t get wet or be exposed to high humidity. If you use an automatic sprayer system to water plants, this option is likely not the best for you.

Best Natural Gas Heaters

As a greenhouse owner, you know it is important to keep your plants warm during the winter. One of the best ways to do this is using a natural gas heater. Using a natural gas heater can protect your plants from a power outage. A conversion kit can convert many natural gas heaters to propane (LP).

Natural gas heaters need safety features and thermostat controls to regulate the greenhouse temperature.

Best Natural Gas Heater
Mr. Heater F260560 Big Maxx Natural Gas Heater
$599.99 $463.99

The Mr. Heater Big Maxx is your natural gas heater of choice. It can heat up to 2,000 square feet with 80,000 BTUs of heating power. The durable steel construction is built to last and includes an integrated handle for easy mobility. It is backed by a limited 3-year warranty on parts and burners.

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11/10/2022 11:49 am GMT

Mr. Heater F260560 Big Maxx Natural Gas Heater

The Mr. Heater F260560 Big Maxx Natural Gas Heater is a powerful greenhouse heater that uses natural gas to heat larger greenhouses.

The heater is designed for large greenhouses and can provide enough heat to keep your plants warm during the coldest months of the year. The Mr. Heater F260560 also has a built-in thermostat so that you can easily control the temperature in your greenhouse.

The heater does come with a Liquid Propane (LP) conversion kit if you don’t have natural gas utility.

The Mr. Heater F260560 is expensive compared to other greenhouse heaters on the market, and you will need a natural gas utility source or propane to use this heater which adds to the operating costs.

radiator heater in greenhouse

What Type of Heater is Best for a Greenhouse?

Greenhouse heaters come in many different shapes, sizes, and forms. Greenhouse heaters run on electricity, natural gas, or propane. Some electric greenhouse heaters can also be placed on the ground or mounted on a wall. Your best greenhouse heater will depend on your specific needs and requirements.

When choosing a greenhouse heater, it is important to consider the size of the greenhouse. You will need to choose one powerful enough to heat the entire space. You may need to purchase multiple heaters if you have a large greenhouse.

It is also important to consider the climate in which you live. If you live in a cold climate for most of the year, you will need a greenhouse heater to withstand the cold temperatures. If you live in a warmer climate, you may not need one too powerful.

Finally, you will need to decide how much money you will spend on a greenhouse heater.

What Size Heater Will You Need?

The size of your greenhouse will play a big role in determining the size of the heater you need. If you have a small greenhouse, you may not need a powerful greenhouse heater. You can heat a small greenhouse with an electric space or propane heater.

Most greenhouses will be about 50sf to 200sf in size. You should anticipate one electric heater for every 100square feet. For 150 to 200 square feet, you’ll need two standard-duty electric heaters or one heavy-duty heater.

You will need multiple heaters with a large greenhouse of over 200 square feet. The best way to determine the size of the greenhouse heater you need is to consult with a greenhouse specialist.

fan-powered greenhouse heater

What is the Best Heater for a Small Greenhouse?

If you have a small greenhouse of less than 100sf (approximately 10′ x 10′), you may not need a powerful greenhouse heater. You can heat a small greenhouse with an electric space or propane heater, provided it’s waterproof.

The Dr. Heater 1500W Greenhouse Infrared Heater listed above is likely all you will need for a small greenhouse or grow tent.

How Much Does it Cost to Run a Greenhouse Heater?

The cost of running a greenhouse heater will vary depending on the type and size of the heater you choose and your climate. An electric space heater is typically less expensive than a propane greenhouse heater.

The size of your greenhouse will also play a role in determining the cost of running your greenhouse heater. You may need to purchase multiple heaters if you have a large greenhouse.

Costs vary widely, but you can expect to pay up to $4 per hour to heat a greenhouse. If you are on solar, costs will be minimal beyond the initial investment. For propane, natural gas, or kerosene, costs can easily approach $400 to $1200 per year.

The biggest factor will be what indoor temperature you are trying to reach compared to the outdoor temperature. If it’s 30 degrees Fahrenheit outside, and you want to heat it to 40 degrees Fahrenheit, an electric heater with solar will have lower costs.

However, if you need to heat from 0 to 40 degrees, electric heat will not do the job, and you’ll spend much more.

How to Keep Your Greenhouse Heater Dry?

Greenhouse heaters need to be kept dry to function correctly. The greenhouse heaters we’ve referenced above have a built-in moisture protection system. You can purchase a separate one if your greenhouse heater does not have a built-in moisture protection system.

How Many BTUs do You Need for a Greenhouse Heater?

The British Thermal Unit, or BTU, is a unit of measurement used to determine heat output. The higher the BTU rating, the more heat output.

You will need to determine the size of your greenhouse to calculate the number of BTUs you need. A small greenhouse will require a greenhouse heater with a lower BTU rating. A large greenhouse will require a greenhouse heater with a higher BTU rating.

The climate in which you live will also play a role in determining the number of BTUs you need. If you live in a warmer climate, you will not need as many BTUs as someone who lives in a colder climate.

Generally, you can anticipate heating about 23 square feet for every 1000BTU (British Thermal Unit). For instance, the BioGreen Basic Electric Fan Heater has 5118BTUs and 120SF coverage.

greenhouse heater

Can You Use a Space Heater in a Greenhouse?

As mentioned above, you can use a space heater in a greenhouse. There are many to choose from, so let us review each kind individually. 

Electrical Space Heaters

Most gardeners use a small heater when greenhouse plants are seedlings. Larger greenhouse sizes need a heater with a higher BTU output. As mentioned above, electrical space radiators are safe and an excellent source for heating your greenhouse. These heaters are used to heat a small greenhouse. 

Because these heaters function on electricity, you are better off using them in an enclosed space, especially if you do not have a well-ventilated area. If you heat a larger greenhouse, it is important to note that you will need quite a few of them, resulting in a higher electricity bill.

However, we will review a few heaters today that can heat a large area, so keep looking for them. 

The worst part of electric space heaters is that they can cause fires, so it is essential to make sure you never place your electric heater somewhere that will get wet or cause a fire, either (i.e., bathroom, near furniture, or appliances.)

Always keep them 3 feet apart from any object, including plants, and never leave or place anything on your heater. 

There are two types of electric heaters to choose from:

  • Convection heaters: will heat the area if the doors and windows are closed. These heaters will function just as effectively inside your greenhouse and household.

    They transfer heat from the warm heater to the surrounding air instead of heating objects. Most convection heaters come with an adjustable thermostat, which is perfect for your greenhouse. 
  • Radiant heaters: include infrared heaters that directly heat the objects within the space instead of the room. They are a wonderful energy-saver compared to convection heating. If you wish to feel warmth without heating the entire room, these are the heaters for you. 

Convectional Fuel-based Space Heaters

Convectional fuel-based heaters are a great option because they heat a large area. These heaters are not designed to heat a smaller area and need ventilation. This is because they emit carbon emissions that can harm your and your plants. So, keep both in mind before purchasing one. 

However, these space heaters are named after their fuel sources, kerosene, natural gas, and wood, which is why they are meant to be used outdoors. Overall, they are a perfect way to heat your greenhouse if it is well-ventilated! 

Ceramic Heaters

These heaters will function on electricity in a tiny box. Since they are tiny, these radiators are an excellent choice for smaller greenhouses. You can place them anywhere you want, and they offer a lot of advantages, such as:

  • Cool-touch exterior.
  • Fairly inexpensive.
  • Minimal fire risks.
  • Energy-efficient.

Oil-filled Heaters

One of the most popular and effective heaters, oil-filled heaters are incredibly safe to use in a greenhouse.

This is because they do not cause fires, and most of them come with an automatic shutoff switch if the heater is too hot, as well as tip-over protection properties if anything were to occur. 

These heaters do not have a fan, so they emit heat through the oil inside an enclosed casing and radiate heat from the coils that come with the case.

Why is it Important to Have a Greenhouse Heater?

You might already know that greenhouses are excellent choices for providing your fruit and veggies with the extra success they need to thrive in winter conditions. It also helps prevent your plants from developing fungus and mold on them.

Heaters are also good for growing tropical plants, even in moderate climates.

On the other hand, you may find that sometimes the cold weather may be a bit too much. This is where heaters are essential. 

When the outside temperature is too cold, a heater can counteract that by emitting heat into the air, especially if there is poor greenhouse insulation or you live in a colder region. 

Best Greenhouse Heater FAQs

What type of heater is best for a greenhouse?

There are three main types of greenhouse heaters: electric, propane, and natural gas. We prefer electric heaters for greenhouses because you can connect to a solar panel as a renewable energy source.

What is the cheapest way to heat a greenhouse?

Electricity is the cheapest way to heat a greenhouse in the long run, especially if you have the option of solar energy. Electric heaters can have a higher initial cost if your greenhouse does not have electricity. However, electric greenhouse heaters remain the cheapest to run despite the initial cost and don’t require natural gas or propane.

At what temperature do you need a heater in a greenhouse?

The answer to this question depends on the plants you are growing. Some plants, like tomatoes, need warm temperatures to produce fruit, so a greenhouse heater is essential. Other plants, like succulents, can tolerate cooler temperatures and may not need a greenhouse heater. Ideally, vegetables have a proper temperature range of 60 to 85 degrees Fahrenheit.

How do you warm up a greenhouse?

The best way to warm a greenhouse is with electric heaters and insulated panels to help hold in as much heat as possible. Heating a greenhouse in winter can be costly, so it’s best to design the greenhouse to hold in as much of the heat as possible.

Final Thoughts

It is an incredible privilege to own a greenhouse right beside your house. However, it is also good to know that you will not have to worry about your plants going bad during that time! 

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Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.
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