Developing a warm, stable environment is crucial for greenhouse crops. This guide highlights gas-based heaters and viable electric options to help you choose a dependable solution for maintaining optimal temperatures. Below are five top picks with varied heating outputs and venting styles, suitable for different greenhouse sizes and setups. Use the summary to compare key specs at a glance.
| Product | Fuel Type | Heats Up To | Vent Type | Approx. Coverage |
|---|---|---|---|---|
| Mr. Heater F260560 Big Maxx MHU80NG | Natural Gas | 80,000 BTU | Vertical/Horizontal Venting | Up to 2,000 sq. ft. |
| Mr. Heater F260550 Big Maxx MHU50NG | Natural Gas | 50,000 BTU | Vertical/Horizontal Venting | Up to 1,250 sq. ft. |
| ProCom MN100TBA-B | Natural Gas | 10,000 BTU | Ventless (Blue Flame) | Up to 500 sq. ft. |
| ProCom MN300TBA-B | Natural Gas | 30,000 BTU | Ventless (Blue Flame) | Up to 1,400 sq. ft. |
| Buyplus Greenhouse Heater | Electric (Not gas) | 1,500W | Ventless Electric | Up to 215 sq. ft. |
The table above shows a mix of gas-fired unit heaters suitable for larger greenhouses and ventless options for smaller spaces or alternative heating needs. When selecting, consider greenhouse size, ceiling height, venting capability, fuel availability, and any ventilation requirements for safe operation.
Mr. Heater Big Maxx 80,000 BTU Natural Gas Unit Heater
This 80,000 BTU natural gas unit heater delivers robust heating suitable for mid-sized greenhouses. It supports 2 angle brackets and a liquid propane conversion kit, though the unit is designed for natural gas operation. It requires a 120 V supply and draws about 2.3 amps. With a 29.33” L x 15.50” W x 26.37” H footprint, it provides substantial coverage up to 2,000 sq. ft. Minimum clearance from the floor to the base is 8 ft. The unit is categorized for vertical venting, with the possibility for horizontal venting in compatible setups.
Key considerations: ensure appropriate venting configuration, verify natural gas availability, and plan for thermostat integration and any required venting components not included.
Mr. Heater Big Maxx 50,000 BTU Natural Gas Unit Heater
This 50,000 BTU natural gas unit heater is a versatile option for medium-sized greenhouses. It supports vertical or horizontal venting, allowing flexible installation to align with existing vent systems. Access to thermostat and gas connections is straightforward via easy outside access. This model balances heating output with efficiency and is well-suited for greenhouses that require consistent but energy-conscious warming, especially in shoulder seasons.
ProCom MN100TBA-B Ventless Blue Flame Heater
This ventless blue flame gas heater provides 10,000 BTU for spaces up to roughly 500 sq. ft. It is designed for indoor living spaces or small workshops, with thermostat control to cycle the heater automatically for steady temperatures. It can be wall-mounted or placed on the floor with included base feet. Note: This model is intended for spaces where vent-free operation is permitted and acceptable by local codes.
ProCom MN300TBA-B Ventless Blue Flame Heater
With 30,000 BTU and ventless blue flame operation, this unit heats up to about 1,400 sq. ft. It includes thermostat control for automatic cycling and can be installed on the wall or used with floor base feet. It is suitable for larger greenhouses or spaces where venting options are limited, provided local regulations permit ventless operation.
Buying Guide
Fuel type and space requirements are the primary considerations when selecting a greenhouse heater. Key factors include:
- Greenhouse size and insulation: Larger spaces benefit from higher BTU heaters or multiple units to avoid temperature swings.
- Fuel availability and safety: Natural gas units require a reliable gas line and proper venting. Ventless models reduce ducting but require strict compliance with safety codes.
- Ventilation: Proper venting is essential for gas heaters to prevent carbon monoxide buildup. Vertical or horizontal vent configurations must align with the unit and site constraints.
- Electrical needs: Some units run on 120 V, while others are vented gas models without electrical load. Ensure electrical systems can handle any required components like fans or thermostats.
- Thermostat control and zoning: Precise temperature control helps protect plants from heat stress and frost. Look for models with built-in thermostats or compatibility with external controls.
- Operating cost and efficiency: Compare BTU output against fuel consumption to estimate ongoing costs. Venting, climate, and setpoint temperatures influence efficiency.
- Installation considerations: Clearance requirements, mounting options, and outdoor versus indoor installation impact long-term reliability and safety.
- Compliance and local codes: Some regions restrict ventless gas heaters in occupied spaces. Always confirm local code compliance before purchase.
For greenhouse managers seeking a gas-based solution, the Big Maxx series from Mr. Heater provides substantial warming capacity for larger spaces, while ProCom offers ventless options that suit smaller areas or partial-venting setups. Electric options like Buyplus provide a quiet, low-profile alternative for smaller greenhouses or zones where gas installation is impractical. When in doubt, consult a professional installer to design a heating layout that maintains consistent temperatures without creating safety risks.