Keeping your plants happy and thriving year-round, especially through chilly nights or frosty winters, is a top priority for any greenhouse enthusiast. And when it comes to consistent, reliable warmth, a small greenhouse propane heater with thermostat can be an absolute game-changer. These clever devices provide the necessary heat to protect your precious plants from damaging cold, ensuring they get the ideal temperature for growth without constant manual adjustments.
Why propane, you ask? Propane heaters are incredibly efficient, often portable, and don’t rely on electricity (unless specified for ignition or fan), making them perfect for off-grid setups or during power outages. Adding a thermostat means you can set your desired temperature, and the heater will automatically kick on and off, saving you fuel and providing stable warmth. It’s all about maintaining that perfect growing environment with minimal fuss!
We’ve scoured the market to find some of the best heating solutions designed for small to medium-sized greenhouses, ranging from dedicated propane units to versatile electric alternatives that offer similar thermostat-controlled benefits. Let’s dive into our top picks to help you make an informed decision for your green haven.
1. Mr. Heater MHVFBF20LPT 20,000 BTU Blue Flame Vent Free
This Mr. Heater unit is a powerhouse for its size, offering a fantastic balance of strong heating capability and smart control. What makes it stand out is its robust 20,000 BTU output, capable of warming spaces up to 700 sq. ft. – perfect for larger small greenhouses or even attached sheds. The built-in thermostat ensures precise temperature management, letting you set it and forget it, while the blue flame technology provides even, convective heating, mimicking the natural warmth of a fireplace.
Key Features:
– Provides up to 20,000 BTUs of heat, warming up to 700 sq. ft.
– Designed for reliable performance even at elevations up to 4,500 ft.
– Features a thermostat for accurate temperature control.
– Hassle-free startup with battery-powered electronic ignition (battery included).
– Factory standard automatic low oxygen shut-off system (Oxygen Depletion Sensor-ODS).
– Blue flame burner uses convection heating for even air distribution.
– Versatile for mounted or free-standing use, with legs & mounting hardware included.
Pros:
– High BTU output for larger spaces.
– Excellent temperature control with thermostat.
– Advanced safety features (ODS).
– Can be wall-mounted or used free-standing.
– Works well at higher altitudes.
Cons:
– Might be overkill for very small greenhouses.
– Requires proper ventilation as it’s vent-free.
User Impressions: Customers frequently praise this heater for its impressive heating power and consistent performance. Many highlight the thermostat’s accuracy and the unit’s ability to maintain a comfortable temperature in their workshops, garages, and larger greenhouses. The ease of installation and the reliable electronic ignition are also commonly mentioned benefits.
2. ProCom ML100TBAHR Ventless Propane Gas Blue Flame Space Heater
For those needing a compact yet effective heating solution, the ProCom ML100TBAHR steps up. This 10,000 BTU blue flame heater is ideal for smaller greenhouses up to 300 sq. ft., offering efficient warmth with the convenience of thermostat control. It’s an economical choice that doesn’t skimp on safety, making it a great option for protecting your plants from sudden cold snaps. Plus, it comes with a generous 10-foot hose and regulator, ready to connect to your standard 20lb propane cylinder right out of the box!
Key Features:
– 10,000 BTU blue flame heater, heats up to 300 sq. ft.
– Thermostat control automatically cycles the burner to maintain desired room temperature.
– Includes a 10-foot hose with regulator for a standard 20lb propane cylinder.
– 99.9% efficient vent-free gas burner, no outside duct or chimney needed.
– Push button Piezo ignition with built-in pilot oxygen depletion sensor (ODS).
Pros:
– Compact size, perfect for small greenhouses.
– Convenient thermostat control.
– High fuel efficiency.
– Ready to use with included hose and regulator.
– Essential safety features (ODS).
Cons:
– Not approved for use in California or Canada (check local codes).
– May not be sufficient for very large small greenhouses.
User Impressions: Reviewers often commend this ProCom heater for its reliable performance in smaller spaces. They appreciate the simplicity of the Piezo ignition and the effectiveness of the thermostat in maintaining a steady temperature. Many users find it to be a dependable and cost-effective heating choice for their compact growing areas.
3. Dyna-Glo IR30PMDG-1 30,000 BTU Liquid Propane Infrared Vent-Free Heater
The Dyna-Glo IR30PMDG-1 offers a different kind of warmth: infrared. Unlike blue flame heaters that warm the air, infrared technology works by radiating heat to objects first, much like the sun. This can be fantastic for directly warming your plants and pots, providing targeted warmth. With a variable heat output from 6,000 to 30,000 BTUs, it’s incredibly versatile for spaces up to 1,000 sq. ft. A huge advantage for greenhouse use is that it requires no electricity, making it a reliable backup heating source during emergencies. While it doesn’t have a built-in thermostat, its variable control knob allows for manual adjustment of heat intensity, giving you customizable temperature management.
Key Features:
– Infrared Technology radiates heat to warm objects directly.
– Variable heat output from 6,000-30,000 BTUs/hr for up to 1,000 sq. ft.
– Variable control knob for customizable heat settings (Low, Med, High).
– No electricity required for operation.
– Optional fan (WHF100) and base legs (WBL100) sold separately.
Pros:
– Direct, radiant heat is efficient for warming plants.
– Highly versatile BTU range.
– Operates without electricity.
– Ideal for emergency heating.
Cons:
– No integrated thermostat; requires manual adjustment.
– Optional accessories for better air circulation and floor mounting are sold separately.
– Not for use with natural gas (liquid propane only).
User Impressions: Customers love the Dyna-Glo infrared heater for its powerful and quick radiant heat, especially in workshops and garages. They appreciate that it doesn’t require electricity, offering peace of mind during power outages. The variable heat settings are frequently praised for allowing users to tailor the warmth to their specific needs.
4. InoKraft Maxheat MH125 125,000 BTU Forced Air Propane Heater
Now, this InoKraft Maxheat unit is a beast! While the title focuses on “small greenhouse propane heater with thermostat,” this 125,000 BTU forced air heater is designed for much larger spaces, specifically up to 3200 sq. ft. It’s truly for those with substantial growing operations, large commercial greenhouses, industrial spaces, or even multiple car garages where serious heat is needed quickly. Its standout feature is the “Smart 25-95°F Auto On/OFF Control,” acting as a robust thermostat to maximize convenience and comfort for demanding heating tasks. If your “small greenhouse” is actually more like a “medium-to-large” greenhouse or you need to heat an adjacent workshop that impacts your greenhouse temperature, this powerful, CSA-certified unit is worth considering for its rapid, widespread heat distribution and advanced temperature regulation.
Key Features:
– Provides 125,000 BTUs, heating up to 3200 sq. ft.
– Smart 25-95°F Auto On/OFF Temperature Control for convenience.
– Heavy-Duty Forced Air Fan for fast heating and wide distribution.
– Adjustable heat angle for versatile use.
– Multi-Protection Safety Features: Overheat Auto-Shut-off and auto-cut-off protection.
– CSA certified for safety.
– Easy operation: plugs into a 115V outlet, hooks up to a 20lb. propane tank or larger.
– Includes a 10 ft hose and regulator.
Pros:
– Extremely powerful, heats large areas rapidly.
– Excellent automatic temperature control with thermostat function.
– Robust safety features.
– Portable with handle, easy to set up.
– Wide range of applications beyond just greenhouses.
Cons:
– Definitely overkill for a truly small greenhouse, might overheat sensitive plants without careful management.
– Requires electricity for the fan and ignition (115V outlet).
– Can be noisy due to forced air fan.
User Impressions: Users with large garages, workshops, and commercial spaces are highly impressed with the InoKraft Maxheat’s ability to quickly and effectively warm vast areas. The auto on/off temperature control is a favorite feature, allowing for set-and-forget operation. Its sturdy build and reliable safety functions also receive positive remarks.
5. VEVOR Greenhouse Heater, 1500W PTC Fast Heating With Thermostat
While our main focus is on a small greenhouse propane heater with thermostat, we know that sometimes an electric option makes more sense for truly compact spaces or where electricity is readily available. The VEVOR Greenhouse Heater is a fantastic electric alternative. It boasts PTC 3-Second Fast Heating technology, delivering 5100 BTU of heat quickly and efficiently. Crucially, it’s designed specifically for greenhouses, addressing humidity and odor issues while creating an optimal growing environment. With its built-in thermostat and hot/cold modes, it offers year-round temperature regulation for your plants. Its IP20 protection and lightweight, portable design make it a versatile choice.
Key Features:
– PTC 3-Second Fast Heating (5100 BTU equivalent) for rapid warmth.
– Specifically designed for greenhouses to address humidity and odor.
– IP20 protection design with ETL certification and overheat protection.
– Multi-scene application: chick brooding, plant tents, greenhouse insulation, drying.
– Hot and Cold Modes (heating and ventilation fan) with three-level temperature adjustment.
– Portable and lightweight (under 5 lbs) with a handle and adjustable 25° angle.
Pros:
– Fast heating, ideal for quick temperature adjustments.
– Built-in thermostat for precise control.
– Addresses humidity and odor common in greenhouses.
– Versatile hot/cold modes for year-round use.
– Very portable and lightweight.
– Safe with multiple protections and ETL certified.
Cons:
– Electric, not propane, meaning it needs an outlet and won’t work during power outages.
– Lower BTU output than many propane options, best for very small greenhouses or as a supplemental heater.
User Impressions: Many users find this VEVOR electric heater perfect for their small indoor grow tents or compact greenhouses. They appreciate its quick heating, quiet operation, and the ability to switch between heating and fan modes. The portability and ease of use are frequently highlighted, as is its effectiveness in maintaining stable temperatures.
6. LHUKSGF Greenhouse Heater with Thermostat, Outdoor Heaters
Here’s another excellent electric option for your temperature-sensitive plants, proving that a small greenhouse heater with thermostat doesn’t always have to run on propane. The LHUKSGF Greenhouse Heater is a modern electric powerhouse designed for precise climate management. It allows you to set temperatures from a very specific 40°F-108°F (5°C-42°C) and choose from 20W/750W/1500W outputs. Its advanced PTC Ceramic technology ensures instant warmth, and its IPX4-rated waterproof/dustproof housing means it’s built to withstand the humid conditions of a greenhouse, making it a reliable guardian for your plants.
Key Features:
– Precisely control temperatures from 40°F-108°F (5°C-42°C).
– Selectable 20W/750W/1500W output for customized climate management.
– Instant PTC Ceramic Warmth technology.
– IPX4-rated waterproof/dustproof housing + anti-corrosion exterior.
– Multi-Purpose: functions as a greenhouse heater, patio warmer, or electric space heater.
– Plug-and-play with hanging hook and ground base options for effortless setup.
Pros:
– Extremely precise digital thermostat control.
– Robust IPX4 rating suitable for humid greenhouse environments.
– Versatile power settings for different needs.
– Instant ceramic heating.
– Easy to install with multiple mounting options.
Cons:
– Electric, not propane, so requires an electrical outlet.
– Max 1500W might be less powerful than some propane options for larger small greenhouses.
User Impressions: Users praise the LHUKSGF heater for its accurate digital thermostat and its ability to consistently maintain desired temperatures in their greenhouses and grow tents. The IPX4 rating gives users confidence in humid environments, and the multiple power settings are appreciated for their flexibility.
7. ProCom ML100TPA-B Ventless Propane Gas Infrared Space Heater
Rounding out our list is another fantastic propane option, the ProCom ML100TPA-B. This compact infrared mini heater generates 10,000 BTUs, efficiently heating up to 500 sq. ft. What’s special about this infrared model is its ability to directly warm objects and plants, similar to the sun’s rays, which can be very beneficial in a greenhouse. It features thermostat control with High/Medium/Low settings, allowing you to regulate the warmth. Plus, it’s a vent-free unit that requires no electricity to operate (except for ignition on some models), making it a truly self-sufficient solution for your plant protection needs, especially during power outages.
Key Features:
– 10,000 BTU Infrared mini heater, heats up to 500 sq. ft.
– Thermostat control offers High/Medium/Low settings.
– Vent-free design, no outside duct or chimney needed.
– Push button ignition with built-in pilot oxygen depletion sensor (ODS).
– No electricity required for operation (perfect for emergencies).
– Can be wall-mounted with included hardware or used on a floor with base feet (included).
Pros:
– Efficient infrared heat directly warms plants and objects.
– Thermostat control for consistent temperature.
– No electricity needed for heating function.
– Compact and stylish design.
– Essential ODS safety features.
– Versatile mounting options.
Cons:
– Requires proper ventilation due to being vent-free.
– Not approved for use in California or Canada (check local codes).
User Impressions: This ProCom infrared heater receives high marks for its ability to quickly warm rooms without relying on electricity. Customers appreciate the radiant heat for making spaces feel cozy, and the thermostat control helps maintain a steady temperature. Its compact size and included mounting options also make it a versatile choice for various users.
Frequently Asked Questions (FAQ)
Choosing the right small greenhouse propane heater with thermostat can bring up a lot of questions. Here are some common queries to help you further:
Q1: How do I determine the right BTU output for my small greenhouse?
A: A common rule of thumb is to calculate the cubic footage of your greenhouse (length x width x height) and multiply that by 5-10 BTU per cubic foot, depending on your climate and desired temperature difference. For a small greenhouse, 5,000-15,000 BTUs is often sufficient, but colder climates or less insulated structures may require more. Our article highlights options from 5,000 up to 20,000 BTUs suitable for various “small” greenhouse sizes.
Q2: Are vent-free propane heaters safe for use in a greenhouse?
A: Vent-free propane heaters are generally considered safe when used according to manufacturer instructions and local codes. They are equipped with Oxygen Depletion Sensors (ODS) that automatically shut off the unit if oxygen levels become too low. However, they do consume oxygen and produce a small amount of carbon dioxide and water vapor. For a greenhouse, ensuring adequate ventilation (even passive) is crucial to prevent moisture buildup and maintain healthy oxygen levels for both plants and any human occupants.
Q3: What’s the main benefit of a thermostat in a greenhouse heater?
A: A thermostat provides automatic temperature regulation. You set your desired temperature, and the heater will turn on when the temperature drops below that point and turn off once it reaches the target. This saves fuel, prevents overheating or underheating, and ensures a stable environment for your plants without constant manual monitoring. It’s essential for consistent plant protection.
Q4: Can I use any propane tank with these heaters?
A: Most small greenhouse propane heaters are designed to connect to standard 20lb BBQ-style propane tanks (like those used for grills). Some larger units might accommodate bigger tanks. Always check the product specifications for compatible tank sizes and ensure you have the correct hose and regulator, which are often included with the heater.
Q5: What’s the difference between blue flame and infrared propane heaters?
A:
* Blue Flame Heaters: These heat the air directly through convection. They warm the surrounding air, which then circulates throughout the space, similar to a traditional furnace. They are good for even, ambient heating.
* Infrared Heaters: These produce radiant heat, warming objects and people directly in their path, much like the sun. They are very efficient at making you feel warm quickly and can be effective for directly warming plants and soil.
Q6: How can I improve the efficiency of my small greenhouse heating?
A: Several tips can help:
– Insulation: Add bubble wrap, polycarbonate panels, or thicker plastic sheeting to your greenhouse walls and roof.
– Sealing: Seal any cracks or gaps where heat can escape.
– Thermal Mass: Place barrels of water inside. They absorb heat during the day and release it slowly at night.
– Circulation Fan: A small fan can help distribute warm air more evenly, preventing hot and cold spots.
– Location: Position your greenhouse in a sunny, sheltered spot if possible.
Q7: Do electric heaters like the VEVOR or LHUKSGF models require special wiring?
A: The electric heaters mentioned (VEVOR 1500W and LHUKSGF 1500W) typically operate on a standard 120V household outlet. While they don’t require special wiring, it’s important to ensure your outlet and circuit can handle the 1500W load to avoid tripping breakers. Always use a grounded extension cord rated for outdoor use if needed, and avoid overloading circuits. They are an excellent alternative to a small greenhouse propane heater with thermostat if you have easy access to electricity and prefer not to deal with propane tanks.
