10 Best Portable Greenhouse Heaters 2025 in the United States

The Dr Infrared Heater DR-268 is a solid choice for those seeking a portable greenhouse heater. With its heating capacity of up to 1500W, it effectively warms areas of 150-200 square feet, making it suitable for greenhouses, garages, and sheds. One of its standout features is the built-in digital thermostat, which allows for precise temperature control, ensuring that your plants stay at the right temperature without wasting energy. User-friendly features like the digital display and selectable Auto or Manual modes also make operation straightforward, even for those who aren't tech-savvy.

Safety is a priority with this heater, as it includes features like overheat protection and is designed to be water-resistant (rated IPX5), allowing it to be used both indoors and outdoors without worrying about damage from moisture. Its construction from dual layers of aluminum helps retain heat effectively, making it especially useful in colder environments.

There are some considerations to keep in mind. The heater requires assembly and, while it has multiple mounting options, it may not be as easy to reposition once installed. Additionally, while it’s energy efficient, being electric means it will add to your electricity bill, especially with continuous use. Lastly, with a one-year limited warranty and USA-based customer support, users can feel secure about their purchase. This heater is particularly suited for gardeners and growers looking for a reliable, versatile heating solution that can easily adapt to different spaces and conditions.

The Mr. Heater Portable Buddy Heater MH9BX is a solid choice for those needing a portable heater for various environments such as workshops, patios, or even camping. With a heating capacity of 4,000 to 9,000 BTUs, it effectively warms spaces up to 225 square feet, which makes it well-suited for small to medium areas. One of its standout features is its advanced infrared technology, providing a cozy, sun-like warmth by directly heating objects and people rather than the air around them.

Safety is a top priority with this heater, as it includes a reliable tip-over safety switch that activates if the unit is disturbed, ensuring that it shuts off if it falls. Additionally, the low-oxygen safety shut-off system adds an extra layer of security for indoor use. The Piezo igniter allows for easy and quick starts, making it user-friendly without the need for matches or batteries.

In terms of energy efficiency, the heater is quite economical, offering up to six hours of warmth on the low setting. This is a big plus for those looking to save on fuel costs while still enjoying reliable heat. Furthermore, its portability is enhanced by a fold-down handle and the ability to connect to both 1 lb. and 20 lb. propane tanks, adding flexibility for different heating needs. While it excels in many areas, the heater is designed for spaces of up to 225 sq. ft., which may limit its use in larger areas. Additionally, being a propane heater, it requires careful handling and ventilation to ensure safety when used indoors.

The Mr. Heater MH9BX-Massachusetts/Canada approved portable propane heater is designed to provide reliable warmth for spaces up to 225 square feet. With its heating capacity ranging from 4,000 to 9,000 BTU, this heater is suitable for smaller greenhouses, especially during cold seasons. One of its notable strengths is nearly 100-percent efficiency, ensuring most of the energy from the propane is converted to heat. However, users should be aware that its performance may decline at altitudes above 7,000 feet, as it may shut off unexpectedly.

Safety is a prominent feature of this heater, with an auto shut-off mechanism if tipped over, if the pilot light goes out, or if low oxygen levels are detected, which is crucial for peace of mind and preventing accidents. The heater is also portable, weighing just 9.5 pounds, with a fold-down handle for easy transportation, making it ideal for moving around different sections of a greenhouse or even using in other outdoor settings.

The heater connects to a propane tank, which is not included, and has a runtime of about 5.6 hours at its lowest BTU setting. While running on propane, it should be noted that using unauthorized accessories can void the warranty and potentially cause safety hazards. It’s important to ensure proper ventilation when used indoors, despite its outdoor usage approval, to prevent any safety risks. Though the heater receives high ratings from users, indicating satisfaction with its performance and reliability, it's crucial that the heater is assembled correctly, following the instructions in the included manual. It's an efficient choice for greenhouse enthusiasts looking for portable heating solutions, though one should weigh the costs of propane usage and ensure it suits their specific environmental needs.