best greenhouse heater

The Best Greenhouse Heater of 2021 with Comparisons & Reviews

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What Makes the Best Greenhouse Heater?

If you’re anything like we are when it comes to gardening, your green thumb itches all year long.

If you aren’t obsessive enough to buy a greenhouse to let you garden in the cold months too, you simply aren’t a constant gardener, and that pun was intended.

What makes a greenhouse heater a greenhouse heater in the first place?

Some plants do not typically stick around in the colder months; but this biological fact can be worked around with the use of a heater for your greenhouse.

Tricking your plants into enjoying an unending spring or summer allows them to stick around longer and produce more fruits for you to enjoy! 

When considering heaters for your greenhouse, start by focusing on the characteristics of your greenhouse itself.

How warm does it keep the air inside it without any kind of heater?

This attribute will greatly depend on if the greenhouse has any insulation, how cold the winter climate is in your area, and also on the greenhouse’s volume. 

Once you know the answers to these questions, you can determine the type of greenhouse heater based on

Check What Hardiness Zone You Are In Here.

The Best Greenhouse Heater

In this review, we provide examples for all situations, and even give you affordable budget options.

Best overall:

The Givebest Portable Electric Space Heater is overall one of the best greenhouse heaters you’ll find on any list for 2021.

Portable Electric Space Heater with Thermostat

2 in 1 heater fan: This ceramic heater provides two heat levels, 1500W or 750W and one cool air fan, you can use it both for winter and summer.

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12/12/2022 02:38 am GMT

Running on 1500/750 watts, the 7″ x 6.2″ x 9.2″ ceramic fan heater heats 200 sq. ft. of an insulated space comfortably; therefore it’s well suited for outdoor small insulated greenhouses in cold climates, and it’s a cool $29.99.

Best budget:

This ceramic fan HAYI space heater is the lightest on your wallet, but don’t underestimate this option!

Electric Ceramic Heater with Over Heat Protection

The indoor heater has three power modes, which allow the indoor heater to blow cold/hot air at different speeds.

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12/12/2022 04:09 am GMT

Using 1500/750 watts, this corded electric space heater can heat both indoor and outdoor non-insulated spaces, like tents, garages or your greenhouse.

It’s also got tip-over protection. 

Best runner up (Eco-Friendly):

What is a PTC heater? PTC stands for a high “positive temperature coefficient,” using special semiconductor ceramics.

Electric PTC Ceramic Space Heater

The indoor space heater equipped with tip over and overheating gears, safe to use for your bedroom, office or home when the floor heater knocked down accidently by your babies & pets or any other cases. Automatically shut off when the tower heater exceeds the range of safe temperature.

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This powerful and efficient power feature allows noiseless heating to 70 degrees Fahrenheit within three seconds, making the PTC 1500w ceramic heater our Best Greenhouse Heaters Runner-Up.

Find your room in immediate warmth using the swiveling heat fan’s High, Low, or even Eco setting (for a smaller power bill without sacrificing your comfort.)

Best under $35:

Multifun’s Portable Ceramic Space Heater has the most features for under $35.

Electric Heater, w/Adjustable Thermostat, (ETL Certified)
$37.98 ($37.98 / Count)

PTC ceramic heating technology provides fast rapid heating and produces no red light or flame. Angled legs make heat distribution wider and allow air blow upwards. Your ideal option to keep your room cozy and get good sleep through the harsh winter.

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12/11/2022 02:08 pm GMT

It heats small spaces excellently both indoors and outdoors uninsulated; and when the cold months are over and your plants are out of their greenhouse, your 1500w Multifun Portable Fan also has a cool air option for summer!

It’s safer than your typical plastic shelled space heater, being made of metal and therefore fire-retardant. 

Alternate 1 (Large Outdoor Spaces): 

The Texsport AC/DC convection heater uses infrared and propane with a ceramic burner, for outdoor use specifically.

Dura Heat TT-15S Heavy Duty Outdoor Camping Steel Single Burner Propane Tank Top Heater Fits Standard 20 Pound Tank
  • Connects to bulk tank (not included)
  • On/off control knob adjusts burner up to 10,000 BTUs
  • Auto shut off valve shuts off fuel if flame goes out
  • Steel reflector with safety grid
  • Durable ceramic burner for even heating and increased heat radiation
  • For outdoor use only

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12/12/2022 05:16 am GMT

This may not be the best option for a regular continuous greenhouse space heater; but for a large greenhouse which you’ll be inside working for any length of time.

It can help make it manageably warm while you’re in there, as well as serve to heat up a large woodshop or garage.  

Alternate 2 (Homes with Pets and Children):

The AgiiMan Convection Patio Space Heater says right there in its product name that it’s an ideal heater for outdoor spaces, especially the likes of your greenhouse.

AgiiMan Patio Space Heater

Advanced ceramic heating elements provide faster and more efficient heating than traditional fan heaters. Ceramic space outdoor heaters can quick heating within 3 seconds, produce abundant heat without open coils, and are long lasting.

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12/12/2022 08:08 am GMT

The portable electric adjustable thermostat heater has an extra long cord for moving to the perfect spot for your plants. It heats quickly, within three seconds.

Its high and low settings use 1500w and 750w respectively, so you can turn down the heat and the bill if needed. It also has an automatic overheat protection system to shut it off when reaching dangerous heats – ideal for a home with children and or pets.


Why isn’t an all-natural method, like a hotbed, a better solution than a space heater?

Depending on how mild the climate is where you live, a composting hotbed made of decomposing biological material may indeed be the best solution to keep your greenhouse warm enough for your plants.

However, if you live anywhere that gets to freezing, you’ll probably need a stronger method.

What are some of the most important features your greenhouse space heater can have besides the basics when considering heaters?

We vote for automatic shutoff or overheating protection, as fires as really a bummer. 

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