Can you put a propane heater in a greenhouse?

Quick Answer

Yes, you can use a propane heater in a greenhouse. Propane heaters are a popular choice for heating greenhouses because propane is efficient, cost-effective, and provides ambient heat that is beneficial for plants. There are some safety considerations when using propane heaters in enclosed spaces like greenhouses, but overall they are a good heating option.

Safety Considerations for Using Propane Heaters in Greenhouses

When using any fuel-burning heater in an enclosed space, there are some safety precautions you should take:

  • Make sure the size of the heater is appropriate for the size of the greenhouse. Follow the manufacturer’s recommendations.
  • Provide proper ventilation. Use vents and fans to bring in fresh air and vent out carbon monoxide.
  • Install a carbon monoxide detector.
  • Keep the area around the heater clear of plants and other combustibles.
  • Inspect the propane tank and lines regularly for leaks.
  • Follow the manufacturer’s lighting instructions carefully.
  • Consider installing an automatic propane shut off valve that will cut off gas flow if the flame goes out.
  • Never leave the heater unattended when in use.

Following basic safety precautions like these will help make sure your propane greenhouse heater is used properly and safely.

The Benefits of Using Propane Heaters in Greenhouses

There are several reasons why propane heaters are a good choice for heating a greenhouse:

  • Efficiency – Propane heaters provide efficient heating. Typically over 90% of the energy in the propane is converted to usable heat. This makes propane very cost-effective.
  • Ambient heat – Unlike electric or forced air heaters, propane heaters provide ambient radiant heat that is not overly drying. This is the type of warmth that plants respond to best.
  • Adjustable heat levels – Most propane greenhouse heaters allow you to adjust the heat output, helping maintain the ideal temperature for your plants.
  • Portability – Smaller propane heaters are lightweight and portable. They can be moved around the greenhouse as needed.
  • Cost-effective – Propane is typically cheaper than electricity, so operating costs are lower compared to electric heaters.
  • Reliability – Propane units provide steady, reliable heat without relying on electricity.

Propane is able to efficiently provide the radiant, ambient warmth that is perfect for a greenhouse environment. The heat can be easily adjusted as needed to account for outdoor weather and temperatures inside the greenhouse.

Best Practices for Using Propane Heaters in Greenhouses

If you decide to use a propane heater in your greenhouse, follow these best practices:

  • Select a propane heater size appropriate for your greenhouse space. Choose a BTU rating that will provide enough heating power but avoid oversizing the unit.
  • Position the heater strategically. Place it toward one end of the greenhouse to allow for proper air circulation. Keep plants, furniture, and equipment at least 3 feet away.
  • Ensure proper ventilation. Use vents on the opposite end to bring fresh air in. Have exhaust fans near the top of the greenhouse to vent out air.
  • Use a backup electric heater. Have an electric heater as a backup in case issues arise with the propane heater.
  • Install a propane gas detector. For safety, ensure you have a detector to alert you of any potential gas leaks.
  • Inspect the propane tank setup routinely. Check for leaks, debris, damage, or other issues.
  • Keep the heater and surrounding area clean. Dust and debris can create fire hazards.
  • Create a level, stable base for the heater. Make sure it cannot be knocked over.
  • Follow all manufacturer instructions. Pay close attention to lighting, operating, and safety guidelines.

Taking these steps will help ensure your propane greenhouse heater is used properly, safely, and provides the right amount of heat for your plants.

Selecting the Best Propane Heaters for a Greenhouse

When selecting a propane heater for your greenhouse, there are a few key factors to consider:

  • Heating power – Make sure to choose a BTU rating appropriate for the size of your greenhouse. Undersizing leads to insufficient heat. Oversizing can be dangerous.
  • Ignition type – Look for units with electric ignition. This eliminates having to manually light the pilot light.
  • Safety features – Seek out heaters with tip-over switches, low-oxygen shutoffs, and thermocouples to prevent issues.
  • Portability – If you need to move the heater around, look for compact portable models with wheels and handles.
  • Durability – Select commercial or industrial grade heaters built of quality components to withstand greenhouse environments.
  • Cost – Consider the purchase price, operating costs, and lifespan when selecting a heater.

Some top propane greenhouse heater options include:

Heater BTUs Key Features
Mr. Heater Big Maxx 80,000 Portable, electric ignition, fan-forced heat
Modine HD 45,000 – 140,000 Powder-coated steel, 99% efficiency
Red Ember ER200SSP 200,000 Stainless steel, industrial capacity

Do some research to find the ideal propane heater based on your greenhouse size, budget, and needs.

Setting Up Propane Tanks and Lines for Greenhouse Heaters

Propane heaters for greenhouses require an external propane tank to supply fuel. Here are some tips for setting up the tank and lines:

  • Position tanks at least 10 feet from the greenhouse. This prevents damage if leaks occur.
  • Place upright portable tanks on a flat, reinforced surface. Secure them so they don’t tip over.
  • For larger permanent tanks, build a concrete base. Install the tank and attachments securely.
  • Bury underground propane lines at least 18 inches. Running lines above ground risks damage.
  • Install a manual shutoff valve near the greenhouse. This makes it easy to shut off gas flow quickly if needed.
  • Use only approved copper, steel, or plastic gas lines. Do not use rubber hosing or damaged lines.
  • Flare fittings should be used to connect the lines. Seal connections with gas-rated pipe compound.
  • Install a pressure regulator to control gas pressure. A 10 psi regulator is common for greenhouse heaters.

Proper setup of the propane tank and fuel lines is crucial for safe operation. Follow local codes and work with a qualified propane technician if you have any uncertainty.

Maintaining Propane Heaters in Greenhouses

To keep your propane greenhouse heater performing properly, follow these maintenance practices:

  • Inspect exterior condition – Routinely check for damage, rust, or holes that could compromise safety.
  • Check burner chamber – Remove debris and make sure the propane orifices are clean.
  • Inspect fuel lines – Look for cracking or leaks. Replace damaged hoses.
  • Clean ventilation areas – Use compressed air to remove dust and debris blocking heat distribution.
  • Test ignition system – Ensure auto ignition and shutoff valves are working properly.
  • Clear area around heater – Remove plants, leaves, and other combustibles within 36 inches.
  • Tune up annually – Hire a professional to inspect and service the heater before winter.

Following the manufacturer’s maintenance schedule and checking your propane heater routinely will keep it running safely and efficiently.

Propane Heater Ventilation for Greenhouses

Proper ventilation is crucial when using any fuel-burning heater in a greenhouse. Ventilation helps:

  • Bring in fresh air to support combustion.
  • Regulate oxygen levels for safety.
  • Prevent buildup of carbon monoxide, nitrogen dioxide, and other gases.
  • Circulate heat and prevent hot and cold spots.
  • Control humidity to prevent mold growth.

Follow these tips to ensure proper greenhouse ventilation with a propane heater:

  • Install vents on both lower and upper parts of the greenhouse to facilitate airflow.
  • Use one or more exhaust fans near the peak to vent out air and gases.
  • Strategically place intake vents to maximize air circulation.
  • Partially open vents near plants to provide good air mixing.
  • Use louvre shutter vents to adjust ventilation as needed.
  • Install a thermostat to control fans based on temperature.
  • Consider a CO/gas detector that triggers exhaust fans if levels rise.

Adequate ventilation allows the heater and plants to operate safely. Consult with greenhouse suppliers about the best ventilation options.

Propane Heater Safety Tips

Propane heaters provide an efficient way to add heat to a greenhouse. But like any heating system, they need to be used properly to ensure safety. Follow these important safety tips:

  • Read and follow the manufacturer’s operating manual.
  • Make sure the heater is an appropriate size for the greenhouse space.
  • Position the heater at least 3 feet from plants and combustible materials.
  • Maintain at least 50% ventilation at all times when the heater is running.
  • Install a propane gas detector in case of leaks.
  • Never leave the heater unattended when in use.
  • Inspect propane lines and connections regularly for leaks.
  • Keep a properly rated fire extinguisher nearby.
  • Do not operate heaters overnight or when the greenhouse is unoccupied.

While propane heaters are quite safe when used properly, complacency can lead to accidents. Stay vigilant and place safety as your top priority.

Troubleshooting Common Propane Heater Issues

Propane heaters may occasionally develop some problems. Here are troubleshooting tips for some common issues:

Issue Possible Causes Solutions
Heater won’t ignite Gas valve off, pilot light out, ignition failure, gas leak Check gas valve, relight pilot, replace ignitor or thermocouple, inspect for leaks
Flame is uneven or yellow Clogged fuel line or orifice, dirty burner Clean fuel line and burner
Heater keeps shutting off Tripped safety switch, thermocouple failure, low gas pressure Reset switch, replace thermocouple, check regulator pressure
Burner not burning completely Insufficient air flow, blocked fuel orifice Check fan operation and air inlets, clean orifice
Flame is too short or tall Incorrect gas pressure, blocked fuel orifice Verify regulator pressure, remove orifice obstruction

Diagnosing the specific issue and making repairs or adjustments can often get a propane heater working properly again.


Propane heaters can be an excellent heating solution for greenhouses when properly installed and maintained. The key factors are selecting a heater suited for the size of your greenhouse, ensuring adequate ventilation, following all safety precautions, and performing regular maintenance. Provided these best practices are followed, propane heaters are able to safely and effectively provide the radiant ambient heat that makes greenhouses ideal for plant growth.