The 6 Best Heaters for Small Greenhouses [In 2025]

Maintaining the right temperature is crucial for successful greenhouse gardening. Whether you’re nurturing delicate seedlings, protecting tropical plants, or extending your growing season, the right heater can make all the difference. In this comprehensive guide, we’ll explore the top 6 greenhouse heaters that can transform your small greenhouse into a thriving plant paradise.

Comparison Table For The 6 Best Heaters for Small Greenhouses

Feature	DECOKTOOL Greenhouse Heater	GRPWWT Greenhouse Heater	Air Choice Outdoor Space Heater	Kiroto Smart Greenhouse Heater	Gardtech Portable Greenhouse Heater	Shinic Garage Heater
Price	Check Price	Check Price	Check Price	Check Price	Check Price	Check Price
Power Output	1500W	1500W	1500W (High Heat) / 750W (Low Heat)	1500W	1500W (High Heat) / 750W (Low Heat)	1500W (High Heat) / 750W (Low Heat)
Heating Technology	Metal Heating Elements	Digital Thermostat Control	PTC Ceramic	Smart APP Control	PTC Ceramic Technology	Tubular Metal Heating
Smart Features	Basic Digital Display	Digital Thermostat	Standard Controls	APP Remote Control, Temperature Alerts	Basic Controls	Manual Thermostat
Coverage Area	Up to 100 sq. ft.	Up to 120 sq. ft.	Up to 100 sq. ft.	Up to 250 sq. ft.	Up to 80 sq. ft.	Up to 150 sq. ft.
Safety Features	Overheating Protection	Overheat & Tip-Over Protection	Overheat Protection	Multiple Safety Systems (Overheat, Tip-Over)	Overheat Protection	Overheat Protection, ETL Listed
Portability	Lightweight (Carry Handle)	Compact Design	Lightweight (3.1 lbs)	Lightweight with APP Control	Extremely Lightweight	Padded Carry Handle
Temperature Modes	2 Modes (Fan & Heat)	Auto Temperature Control	3 Modes (Low Heat, High Heat, Fan)	Heating & Fan Modes	3 Modes (High Heat, Low Heat, Fan)	3 Modes (Low Heat, High Heat, Cool Air)
Noise Level	Moderate	Low	Low	Low	Ultra-Quiet (<36 DB)	Moderate to High
Special Features	Integrated Hygrometer	Energy Efficient	90° Tilt Rotation	70° Swing Mode	PTC Ceramic Sheet Technology	60° Adjustable Heating Angle
Color Options	Yellow	Black	Light Yellow	Silver	Orange	Yellow+Black
Ideal For	Small Personal Greenhouses	Medium Greenhouses	Compact Spaces	Tech-Savvy Gardeners	Quiet Environments	Durable Industrial Use
Best Use Case	Home Gardeners	Professional Growers	Portable Needs	Remote Monitoring	Noise-Sensitive Areas	Workshop/Garage Environments
Connectivity	Basic Controls	Wired Thermostat	Standard Plug	WiFi/APP Control	Standard Controls	Manual Controls
Energy Efficiency	Good	Excellent	Good	Very Good	Good	Good
Durability Rating	4/5	5/5	4/5	4/5	3/5	5/5
Customer Satisfaction	4.2/5	4.5/5	4.3/5	4.4/5	4.1/5	4.0/5

Key Insights:

• Most Versatile: Kiroto Smart Greenhouse Heater
• Best Budget Option: Air Choice Outdoor Space Heater
• Most Durable: Shinic Garage Heater
• Most Technologically Advanced: GRPWWT Greenhouse Heater
• Quietest Option: Gardtech Portable Greenhouse Heater

Why Proper Heating Matters 

Greenhouses are magical spaces where plants can grow beyond their typical seasonal limitations. However, without proper heating, your green haven can quickly become a frost-bitten disappointment. Temperature fluctuations can stunt plant growth, damage sensitive plants, and ultimately compromise your entire gardening effort. A reliable greenhouse heater isn’t just a luxury – it’s a necessity for serious plant enthusiasts. 

Key Factors to Consider 

When selecting a greenhouse heater, several critical factors come into play:

• Heating Capacity: Ensure the heater can effectively warm your specific greenhouse size
• Energy Efficiency: Look for models that provide maximum heat with minimal electricity consumption
• Safety Features: Overheat protection, tip-over protection, and reliable thermostats are essential
• Portability: Ability to move and position the heater as needed
• Noise Level: Some heaters can be disruptively loud
• Additional Features: Smart controls, oscillation, multiple heat settings 

Top 6 Greenhouse Heaters Reviewed 

1. DECOKTOOL Greenhouse Heater: The Versatile Performer  

Pros:

• Powerful 1500W heating capacity
• Integrated thermostat and hygrometer
• Two mode options (fan and heat)
• Compact and portable design

Cons:

• Limited to indoor/outdoor use
• May not be suitable for extremely large spaces 

2. GRPWWT Greenhouse Heater: The Smart Temperature Manager 

Pros:

• Precise digital thermostat
• Fast 3-second heating
• Covers up to 120 sq. ft.
• Fireproof materials
• Energy-efficient design

Cons:

• Potential initial plastic odor
• Slightly higher price point 

3. Air Choice Outdoor Space Heater: The Flexible Solution 

Pros:

• Three mode settings (750W and 1500W heat, fan mode)
• 90-degree tilt rotation
• Lightweight and portable
• ETL certified for safety

Cons:

• Limited to indoor use
• May not be suitable for very large greenhouses 

4. Kiroto Smart Greenhouse Heater: The Tech-Savvy Option 

Pros:

• Smart app control
• Remote temperature monitoring
• Swing mode for even heat distribution
• Multiple safety features
• Temperature alerts

Cons:

• Requires smartphone app
• Slightly more complex setup 

5. Gardtech Portable Greenhouse Heater: The Quiet Performer 

Pros:

• PTC ceramic heating technology
• Three speed settings
• Ultra-quiet operation (less than 36 DB)
• Lightweight and portable
• Overheat protection

Cons:

• Limited to smaller spaces
• May not be ideal for very large greenhouses 

6. Shinic Garage Heater: The Durable Workhorse 

Pros:

• Heavy-duty metal construction
• Three heating modes
• 60-degree adjustable angle
• ETL listed safety features
• Padded carry handle

Cons:

• Some users report noise issues
• Limited to indoor use 

FAQs 

1. How do I determine the right heater size for my greenhouse? 

Measure your greenhouse’s square footage and choose a heater with appropriate heating capacity.

2. Can I use these heaters year-round? 

Most of these heaters offer multiple modes, including fan settings for summer and heat settings for winter.

3. Are greenhouse heaters safe to use around plants? 

When used correctly with proper safety features, these heaters are designed to be plant-friendly.

4. How much electricity do greenhouse heaters consume? 

Consumption varies, but most models range between 750W to 1500W. Check the specific energy rating of each model.

5. Do I need additional temperature monitoring equipment? 

Some heaters come with built-in thermostats and hygrometers, but a separate temperature monitor can provide additional peace of mind.

Conclusion 

Choosing the right greenhouse heater is a nuanced decision that depends on your specific needs, greenhouse size, and plant varieties. Each of these six heaters offers unique advantages, from smart technology to robust heating capabilities. Consider your specific requirements, budget, and greenhouse conditions when making your selection.