6 Best Greenhouse Heater in 2021 {Updated Review}

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NOTHING is more important than the ideal temperature for a plant. Place it in the wrong environment, and it will either struggle to grow or eventually die.

This is especially true for cold places. Areas, where temperatures are rarely warm, will make for challenging environments for some species to thrive.

The solution? Easy: the best greenhouse heater.

A heater can make even the most inhospitable of places decent enough for any species to prosper. But that’s only if you pick the RIGHT ONE. Otherwise, you’re set to be disappointed.

Don’t want to be disappointed? Then check the heaters below…

The Best Greenhouse Heater (Our Top 6)

After carefully looking through all their features, checking their ins and outs, and finding what makes each heater the BEST in its specific way – we ended up with 7 heaters.

Here’s what we found about them:

Image Product
Bio Green Palma Thermo2 Greenhouse Heater
  • Rugged construction with steel housing
  • Spraywater proof
  • excellent temp controls
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Dr. Heater DR218-1500W Greenhouse Infrared Heater
  • Light weight and portable
  • Low maintenance needed
  • Super-tough construction
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OPOLAR Ceramic Space Heater
  • QUICK HEATING FOR INSTANT WARMTH
  • THREE MODES HEATER WITH FAN
  • ADJUSTABLE THERMOSTAT
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Comfort Zone CZ220 Fan-Forced Ceiling Mount Heater
  • SPACE-SAVING DESIGN
  • DURABLE STEEL CONSTRUCTION
  • TARGETED HEATING
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STANLEY ST-300A-120 Forced-Air Electric Heater
  • POWERFUL
  • FAST HEAT
  • Easy carrying
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ISILER Space Heater
  • SAFE and RELIABLE
  • COMPACT, PORTABLE & CONVENIENT
  • ADJUSTABLE THERMOSTAT CONTROL
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Below is the list of our top pics of Greenhouse Heaters with advantages and disadvantages.

#1. Bio Green Palma Thermo2 Greenhouse Heater 

Bio Green PAL 2.0/USDT Palma Greenhouse Heater incl. Digital Thermosta
645 Reviews
Bio Green PAL 2.0/USDT Palma Greenhouse Heater incl. Digital Thermosta
  • Easily heats spaces up to 120 ft. ² ideal for greenhouse heating, sheds, store room, garage, milk-house
  • With digital summer/winter thermostat (110 V) UL - Approved and external sensor cable to measure the ambient temperature in the greenhouse.

Fan-powered heaters are nearly perfect for greenhouses.

The reason? They’re typically small, provide efficient circulation, and maintain the heat more consistent inside the greenhouse.

This Bio Green heater is an excellent example of that.

The Palma focuses on delivering quality heating, going up to 210 degrees Fahrenheit. And suppose you need to keep temperatures below 32 degrees. In that case, that’s also possible with the added digital thermostat (it makes temp changes EFFORTLESS).

Bio Green PAL 2.0/USDT Palma Greenhouse Heater incl. Digital Thermosta

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Its accuracy is otherworldly, making its circulation even more effective as it comes with 5120 BTU of heating power. Alongside 1500 watts of output, the heater offers up to 163 cubic meters of air circulation per hour.

You could use it for greenhouses as large as 120 square feet, and there shouldn’t be a problem. It’s still cheap to use and withstands light humidity thanks to an IPX4 waterproof build.

PLUS: You get a stainless-steel construction almost in its entirety, ensuring a durable product from every angle (it’s also made in Germany).

What We Liked

  • Small and handy design for easy use
  • Sufficiently potent for most greenhouses
  • Reliable and rugged build that lasts
  • Comes with excellent temp controls

What We Didn't Like

  • Does not work for greenhouses bigger than 10-by-10 feet

#2. Dr. Heater DR218-1500W Greenhouse Infrared Heater

Sale
Dr. Heater DR218-1500W Greenhouse Garage Workshop Infrared Heater, 1500-watt
458 Reviews
Dr. Heater DR218-1500W Greenhouse Garage Workshop Infrared Heater, 1500-watt
  • 1500W comes with only one setting
  • Keeping your tender plants warm and thrive in the best climate

There’s no mistake about it. Dr. Heater ALWAYS delivers. And the DR218-1500W is not an exception.

What sets this one apart is the design. It is small, space-efficient, and secure. You can make it work on practically any greenhouse, and it will SURPASS all your expectations.

This is a low-maintenance infrared heater, by the way. This gets better with the heavy-duty ball-bearing motor, an enclosed motor build, and high-end lubrication. Meaning, you will never need to do any maintenance or worry about its durability.

And to make it better, it boasts an IPX4 construction. So you won’t have to worry about water splashes or even high humidity causing damage to the piece.

Dr. Heater DR218-1500W Greenhouse Garage Workshop Infrared Heater, 1500-watt

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As for heating performance, you get a precision temperature sensor with adjustable thermostat control. So you can choose almost any temp and keep it stable for your plants to thrive in the greenhouse.

Remember: It is a 1500-watts heater that can cover up to 150 square feet. You can use it on small or large greenhouses alike.

What We Liked

  • Super-tough construction lasts a lifetime
  • Practical design for easy handling
  • Works with medium-sized greenhouses
  • Offers consistent heating performance

What We Didn't Like

  • Consumes A LOT of electricity

#3. OPOLAR Ceramic Space Heater 

OPOLAR 1500W Ceramic Space Heater with Adjustable Thermostat, Fast Heating for Small and Middle Rooms, Office Floor, Desk or Other Indoor Space, Powerful and Portable, ETL Approved
1,391 Reviews
OPOLAR 1500W Ceramic Space Heater with Adjustable Thermostat, Fast Heating for Small and Middle Rooms, Office Floor, Desk or Other Indoor Space, Powerful and Portable, ETL Approved
  • 🔥【QUICK HEATING FOR INSTANT WARMTH】 - Ceramic space heaters are fast to heat, produce abundant heat without open coils, and are long lasting
  • 🔥【THREE MODES HEATER WITH FAN】-1.High Heat (1500-watt), 2. Low Heat (1000-watt ), 3. Fan Only.

Are you a simplicity lover? Then look no further than the OPOLAR ceramic heater.

You get all the benefits from infrared systems (speed and reliability) with the effectiveness of fan-forced heaters (warmth circulation and ease of use). But this ceramic heater goes a step further: it’s also quiet.

Doesn’t that sound great (pun intended!)?

You can keep all your plants inside the greenhouse warm using the different levels (High Heater at 1500 watts or Low Heat at 1000 watts). But you can also enjoy a barely audible 50dB fan, ideal for indoor greenhouses or grow tents.

This ceramic heater is incredibly safe too. Overheating protection, tip-over safety feature, and rugged construction keep it working for years to come.

OPOLAR 1500W Ceramic Space Heater with Adjustable Thermostat, Fast Heating for Small and Middle Rooms, Office Floor, Desk or Other Indoor Space, Powerful and Portable, ETL Approved

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The heater is ultra-small and makes it a space-efficient choice (no need to move your plants around to fit it inside the greenhouse). And with its practical top handle, carrying it will be a no-brainer.

DON’T FORGET: It is one of the most consistent heaters on the list, both for its ceramic heating element as well as its reliable adjustable thermostat.

What We Liked

  • Comes with the handiest of designs
  • Consumes little energy
  • Performs as quietly as you can imagine
  • Delivers super-consistent heating

What We Didn't Like

  • Struggles to heat up large spaces

#4. Comfort Zone CZ220 Fan-Forced Ceiling Mount Heater 

Comfort Zone CZ220 5,000W, Fan-Forced Ceiling Mount Heater with Dual Knob Controls
1,508 Reviews
Comfort Zone CZ220 5,000W, Fan-Forced Ceiling Mount Heater with Dual Knob Controls
  • SPACE-SAVING DESIGN: The fan-forced heater is designed for ceiling mounting and hard-wired installation, which saves valuable floor space in a packed warehouse, garage or storage area.
  • DURABLE STEEL CONSTRUCTION: The body of the commercial heater is crafted from heavy gauge steel, which stands up well to the temperature fluctuations in areas that are poorly insulated.

Save space in your greenhouse with a ceiling-mounted heater like the CZ220 from Comfort Zone.

Hang it directly from the greenhouse ceiling, let it deliver all the heat directly into your plants.

Enjoy its manual controls, placed just below the heating element. Don’t let it push warm air to a place you don’t want, adjust the front fins as needed. And if you need even more versatility, use the adjustable mounting handle to change its angle however you prefer.

You don’t have to be scared about it being too powerful. It uses 240-volt power to heat up, but it’s still super-safe thanks to the built-in sensor and power light, preventing overheating and letting you know when it’s on.

Comfort Zone CZ220 5,000W, Fan-Forced Ceiling Mount Heater with Dual Knob Controls

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It’s also made from high-quality steel so that you can enjoy a long-lasting product. So don’t be scared about it breaking down after a few months (it won’t rust either!).

Worth knowing: It is a commercial-level heater that works in small or large greenhouses with no problems.

What We Liked

  • Perfect for the biggest greenhouses
  • Rarely breaks down
  • Goes almost anywhere
  • Offers decent air circulation

What We Didn't Like

  •  Consumes a lot of electricity

#5. STANLEY ST-300A-120 Forced-Air Electric Heater

ISILER Space Heater, 1500W Portable Indoor Heater, Ceramic Space Heater Adjustable Thermostat Tip-Over Overheat Protection, Hot Cool Fan Electric Heater for Home Office Garage with ETL Certified
3,182 Reviews
ISILER Space Heater, 1500W Portable Indoor Heater, Ceramic Space Heater Adjustable Thermostat Tip-Over Overheat Protection, Hot Cool Fan Electric Heater for Home Office Garage with ETL Certified
  • SAFE & RELIABLE: This small space heater made from fire-retardant materials; The ceramic heater has a self-regulating element and automatic overheating protection for added safety. Tip-Over Protection will shut off the room heater if it gets knocked over accidentally to avoid accident happens. It will automatically shut it off if the temperature exceeds the limit value and back to work once it gets to a safe temperature inside.
  • ADJUSTABLE THERMOSTAT CONTROL: Features a temperature range of 41 °F-95 °F; Rotate the thermostat control dial to lower the temperature once the room is warm, this ceramic heater will greatly reduce power consumption.

Give your greenhouse the best cheap heater out there… The ST-300A-120 from Stanley.

It’s not a mistake when we say it is the BEST for its size and price.

Just think about it:

  1. It offers 1500 watts of output with 5100 BTU of heating power. That’s enough to cover up to 165 square feet.
  2. It is so small that you can fit it inside a travel bag.
  3. It is light and easy to bring around, weighing barely 6 pounds and boasting an easy-lift handle.

The combination of all these features UNDOUBTEDLY makes it an electric heater you don’t want to miss. Add the fan-forced system that heats up any place in just a few minutes, and you’ll be AMAZED.

ISILER Space Heater, 1500W Portable Indoor Heater, Ceramic Space Heater Adjustable Thermostat Tip-Over Overheat Protection, Hot Cool Fan Electric Heater for Home Office Garage with ETL Certified

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It is still safe with an overheating protection system, an auto-shutoff, and a rugged build. So you won’t have to worry about it even after years of use (AND FOR CHEAP!).

YOU SHOULD KNOW: It comes with an adjustable angle frame and a practical set of controls (for temperature and heating mode), so there’s NOTHING to hate about it.

What We Liked

  • The tiny design fits almost anywhere
  • Provides excellent heating for its size
  • It is very affordable despite its quality
  • Offers incredible versatility & adjustability

What We Didn't Like

  • Doesn’t work in big greenhouses

#6. ISILER Space Heater

STANLEY ST-300A-120 Electric Heater, Black, Yellow
322 Reviews
STANLEY ST-300A-120 Electric Heater, Black, Yellow
  • POWERFUL: 1500 Watt/12. 5 amps capacity heats up to 165 sq. feet.
  • VERSATILE: Two (2) heat settings with adjustable thermostat let you choose how much heat you need.

Give your wallet a chance with a cheap heater like the ISILER.

You may think affordable heaters are unreliable. But this one is none of that. It offers a low price with fantastic construction using fire-retardant materials, a self-regulating element, overheating protection, and a tip-over system.

Are you a careless greenhouse user? Then you’ll love an inexpensive yet dependable heater like this.

There’s a lot more to enjoy. The small design, for example, weighs barely 2.3 pounds and measures not more than 7 inches. Add the ergonomic handle to make it even more practical.

STANLEY ST-300A-120 Electric Heater, Black, Yellow

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As for heating capacity, you can enjoy a 1500-watt output. That’s enough to heat up a 108 square feet space in just a couple of minutes. Best of all? You can adjust temperatures from 41 to 95 degrees Fahrenheit with the handy knob on top.

LAST BUT NOT LEAST: It is barely audible thanks to a 50dB fan. You will hardly hear it when it’s inside a greenhouse, so it becomes a go-to alternative for small portable greenhouses.

What We Liked

  • Small and easy to bring around
  • Delivers decent heating for its size
  • Produces little to no noise
  • It’s safe and reliable

What We Didn't Like

  • The fan never turns off

What to Consider Before Picking a Greenhouse Heater?

Did you check all our heaters above? If yes, you were probably left with a few doubts.

Don’t worry about that. It’s normal. Learning about so many heaters can be overwhelming.

On top of that, we brought a brief but helpful guide on picking the right one. It will show you EVERY feature you need to know about:

  • Power Output

Let’s start with the obvious: how powerful do you need the heater to be?

More importantly, how big is the greenhouse?

These two questions will make it easy to understand what potency you need. First, be aware that power output is measured in two ways.

One would be BTU (British Thermal Units). It is how much HEAT you get from the heater. Having at least 5000 BTUs is always ideal for greenhouse heaters.

The second would be watts. This refers to how much power the heater draws. The amount of power may vary depending on how you configure it (heaters often have at least two different levels). For a decent output, we recommend at least 1000 watts.

NOW, you should consider whether the output is enough for the greenhouse size. A typical garden greenhouse is about 100 square feet. The heater you pick should cover that amount of space effortlessly.

  • Heating Speed

There’s no way to measure how fast the greenhouse heats. But taking a look at how much power it offers can be a great idea.

The more power the heater offers, the faster it will heat up. Also, consider how BIG the heater is. Small ones will struggle to heat up quickly.

Also, consider how cold it gets in the area you’re placing the greenhouse. Cold environments tend to make heaters heat up a lot slower (so you may need a quicker-to-heat model).

  • Temperature Levels and Controls

A heater should also disclose the different degrees it works with (its lowest and its maximum).

This often comes alongside the controls. For example, you may find out whether it offers two, three, or more temp levels. Also, its heating modes may give you a hint of how it works (slow heating, fast heating, fan-only, etc.).

Overall, make sure the temp levels match your needs (considering how cold it gets in your area). The controls are practical enough for your needs (various modes to match different seasons).

  • Size and Installation

Heaters for greenhouses need to be small to fit inside but also large to heat everything. There’s no doubt about that. So you must consider how much space there’s available in the greenhouse.

Small models (4 by 4 feet, for example) will only work with tiny heaters. But large greenhouses (over 10 by 10 feet) may host a big heater with no trouble.

Once you get the size figured out, consider how it is installed. For example, some greenhouses need to be hanged or attached to walls/ceilings. But most of these heaters are standing, so you need no installation at all.

LASTLY, consider how portable it is. Obviously, bigger ones will be trickier to bring around. But do they come with handles and other features for more portability? Have that in mind before picking.

Types of Greenhouse Heaters to Consider:

Familiar with the features you need to consider? If yes, let’s now give you a heads-up on the different heaters you will encounter:

  • Fan-Forced Heaters

As the name says, they come with an internal fan and a steel heating element. The element produces the heat, and the fan disperses it around.

  • Ceramic Heaters

Similar to fan heaters, but the heating element is made of ceramic. These are often much more efficient and consume less electricity.

  • Infrared Heaters

There are no fans or heating elements inside these heaters. They use electromagnetic radiation from a bulb instead. This bulb tends to be long-lasting, efficient, and quick to heat up.

How to Increase Greenhouse Temperature Without a Heater?

Let’s suppose no heater from above clicks your buttons. What can you do to keep that greenhouse warm in that case? Here are some tips:

  • Expose it to Sunlight

A greenhouse that receives direct sunlight most of the day will stay warmer than the one staying all day under shade. Even artificial grow lights or similar non-natural light sources are half as good as actual sunlight, especially in warm seasons like spring or summer.

  • Use Heat-Retentive Materials

Greenhouses made of PVC, polycarbonate, glass, or acrylic tend to retain a lot more heat than those made with fabrics. They absorb heat more effectively and keep it inside for longer.

  • Keep Humidity High 

Believe it or not, high humidity increases the temperature inside the greenhouse by condensing the environment. It creates vapor that retains heat and increases temperature, sometimes exponentially. Use a humidifier or misting system for that.

Frequently Asked Questions (FAQs)

Q. What is the best type of heater for a greenhouse?

A. Greenhouses work better with fan-forced heaters because they circulate the air much more effectively than other types.

Q.Should you use a gas heater in a greenhouse?

A. We don’t recommend gas heaters because they’re more dangerous. As greenhouses are often small and enclosed, they trap toxic fumes and smokes coming out of the gas burning. This could cause damage to some plant species.

Q.How much does it cost to run a greenhouse heater?

A. A 1500-watt electric heater for your greenhouse may consume anywhere from $2 to $15 every 24 hours. This depends on electric rates in your area.

Q.What is the ideal temperature for a greenhouse?

A. The answer lies in the plants you want to grow inside. You need to adapt the temperature to your plants’ needs over anything else. Generally, people use greenhouses to keep temperatures between 60 and 90 degrees in cold areas.

Conclusion

So, did you find the best greenhouse heater for your garden on the list? WE HOPE SO!

If you did, then you’re ready to take the right one home. And believe us when we say you won’t regret it.

This decision will change how your plants fare. So don’t take it lightly and pick the best one possible!

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