Top-Rated Space Heaters for Greenhouses: A Comprehensive Guide

Greenhouses are essential for maintaining optimal growing conditions, especially in cooler months or regions with unpredictable weather. A key aspect of greenhouse management is temperature control, which directly impacts plant health, growth, and yield. Choosing the right space heater for your greenhouse can be a game-changer in maintaining a stable environment for your plants, whether you're growing vegetables, flowers, or tropical plants.

In this actionable guide, we will delve into the factors to consider when selecting a space heater for your greenhouse, as well as provide a list of top-rated heaters based on efficiency, ease of use, and performance.

Why You Need a Space Heater for Your Greenhouse

1. Temperature Regulation

Plants thrive in consistent temperatures. Many plants have specific temperature needs, and when the greenhouse becomes too cold at night or during cold weather, growth can slow down or even halt completely. A greenhouse heater helps to maintain these ideal conditions.

2. Extend Growing Seasons

A space heater is especially important for extending growing seasons. If you want to start growing plants earlier in the spring or extend the harvest in the fall, providing supplemental heat in your greenhouse is crucial.

3. Prevent Frost Damage

Cold snaps and frost can be disastrous for crops. A greenhouse heater can help prevent frost damage by keeping the environment above freezing, which is critical for sensitive plants.

4. Energy Efficiency

Running a greenhouse can be expensive, and inefficient heating can drive up costs. A good space heater will offer high performance without wasting energy, ensuring your heating bill stays manageable while still providing optimal conditions for your plants.

Key Factors to Consider When Choosing a Space Heater for Your Greenhouse

1. Heating Capacity (BTUs)

The heating capacity of a space heater is measured in BTUs (British Thermal Units). The higher the BTU rating, the more heat the unit can provide. When selecting a space heater, consider the size of your greenhouse and the plants you're growing. Small greenhouses may need only a heater with a lower BTU rating, while larger, commercial greenhouses will require more powerful models.

• Small Greenhouses (< 200 sq. ft.): Look for heaters with 5,000--15,000 BTUs.
• Medium Greenhouses (200--500 sq. ft.): Heaters with 15,000--30,000 BTUs.
• Large Greenhouses (> 500 sq. ft.): Heaters with 30,000--50,000 BTUs or more.

2. Fuel Type

The fuel type of the space heater is an important factor, as it will influence the heater's cost, maintenance, and environmental impact. There are several types of heaters available:

• Electric Heaters: These are easy to use and maintain but can be costly to operate over large areas.
• Propane Heaters: Propane heaters offer portability and are effective in large spaces, but you will need to ensure proper ventilation.
• Natural Gas Heaters : Ideal for large, permanent greenhouse setups, natural gas heaters are efficient but require a gas supply.
• Kerosene Heaters: These are effective for large areas but require regular refueling and careful ventilation.

3. Safety Features

Safety is a top priority, especially in an environment that contains plants and possibly flammable materials. When selecting a heater, look for features like:

• Tip-over protection: Automatically shuts the heater off if it is knocked over.
• Overheat protection: Turns off the heater if it exceeds a safe temperature.
• Oxygen depletion sensor : Stops the heater if the oxygen levels fall too low (important for propane or kerosene heaters).

4. Heating Method

Different space heaters employ different heating methods. Some of the most common include:

• Convection Heaters: These heaters work by warming the air and circulating it through the greenhouse. They are quiet and provide even heat distribution.
• Radiant Heaters : Radiant heaters emit heat in the form of infrared radiation, warming objects and plants directly. These heaters are ideal for smaller areas and more precise heating.
• Fan-Forced Heaters: These heaters use a fan to distribute heat throughout the greenhouse. They provide fast and even heating but can be noisy.

5. Energy Efficiency

Energy efficiency is crucial for long-term operational cost management. Look for heaters with energy-saving features such as thermostats and timers that help maintain a consistent temperature without wasting energy.

Top-Rated Space Heaters for Greenhouses

1. EcoSmart ECO 27 Electric Tankless Water Heater

Features:

• Fuel Type: Electric
• BTU Rating: Equivalent to 27 kW
• Heating Method: Convection
• Safety Features: Overheat protection, freeze protection
• Energy Efficiency: 99% energy-efficient, only heats water as needed
• Additional Features: Wi-Fi connectivity, temperature control

Why It's Great:

The EcoSmart ECO 27 is an energy-efficient, electric space heater that works by heating water, which is then circulated throughout your greenhouse to provide warmth. This type of heating is particularly effective for larger greenhouses, offering consistent and reliable heat. The heater's compact size and high energy efficiency make it an ideal choice for gardeners who want to minimize energy consumption while maintaining a stable temperature.

2. Mr. Heater Big Maxx Natural Gas Heater

Features:

• Fuel Type: Natural Gas
• BTU Rating: 45,000 BTUs
• Heating Area: Up to 1,000 sq. ft.
• Heating Method: Convection
• Safety Features: Auto shutoff, overheat protection
• Additional Features: Easy installation, adjustable thermostat

Why It's Great:

The Mr. Heater Big Maxx is perfect for larger greenhouses that require significant heating. With its 45,000 BTUs, it can quickly heat up to 1,000 sq. ft. of space, making it ideal for both commercial and hobbyist greenhouse growers. This natural gas heater is designed for efficiency and safety, with features like auto shutoff and overheat protection.

3. Dyna-Glo KFA50DGD Kerosene Forced Air Heater

Features:

• Fuel Type: Kerosene
• BTU Rating: 50,000 BTUs
• Heating Area: Up to 1,200 sq. ft.
• Heating Method: Forced Air
• Safety Features: Overheat protection, automatic shutdown
• Additional Features: Portable, large fuel tank (can run for 8 hours)

Why It's Great:

The Dyna-Glo KFA50DGD is a powerful kerosene heater designed for larger greenhouses or cold storage areas. Its 50,000 BTU output makes it one of the most powerful heaters for greenhouse use, ideal for areas with high heat requirements. The forced-air heating method ensures fast heat distribution, and the portability of the heater allows it to be used in different parts of the greenhouse.

4. Vornado AVH10 Vortex Heater

Features:

• Fuel Type: Electric
• BTU Rating: 5,000 BTUs
• Heating Method: Convection, Vortex air circulation
• Safety Features: Tip-over protection, overheat protection
• Additional Features: Quiet operation, adjustable thermostat

Why It's Great:

The Vornado AVH10 is a compact, efficient electric heater perfect for small to medium-sized greenhouses. Using Vortex technology, it circulates warm air evenly throughout the greenhouse, ensuring consistent temperatures without the noise and disruption of larger models. Its small size and quiet operation make it a great option for areas where space is limited or where you want minimal disturbance.

5. Heatstar by Enerco F170300 Forced Air Heater

Features:

• Fuel Type: Propane
• BTU Rating: 170,000 BTUs
• Heating Area: Up to 4,000 sq. ft.
• Heating Method: Forced Air
• Safety Features: Overheat protection, tip-over switch
• Additional Features: Portable, durable metal housing

Why It's Great:

For large greenhouse operations, the Heatstar F170300 offers massive heating capabilities. With a BTU rating of 170,000, it is capable of heating large spaces effectively. This propane-powered heater is designed for heavy-duty applications, providing fast and even heating to expansive areas. It's built for portability and durability, making it a perfect choice for commercial growers.

Conclusion

Choosing the right space heater for your greenhouse is a crucial decision that directly impacts your plants' health and your energy bills. Factors such as the size of your greenhouse, the type of plants you're growing, and your preferred fuel source will all guide your decision.

From electric convection heaters like the EcoSmart ECO 27 to the powerful propane options like the Heatstar F170300, the market offers a variety of reliable heaters for greenhouse use. Consider energy efficiency, safety features, and heating method when making your decision to ensure a consistent and healthy growing environment for your plants.