10 Best Portable Greenhouse Heaters 2025 in the United States

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 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 F215100 MH4B Little Buddy is a portable propane heater with a capacity of 3,800 BTU, ideal for small spaces up to 95 square feet. It is designed for both indoor and outdoor use and is perfect for heating small enclosed areas such as tents, workshops, and garages. One of its key strengths is the automatic low oxygen shut-off system, which ensures safety by turning off the heater if oxygen levels drop. Additionally, it features a tip-over switch that offers extra protection against accidental knock-overs, making it a safe choice for various settings.

The heater operates odor-free and has a 45-degree heating angle, enhancing comfort in small spaces. It uses a 1-pound disposable propane cylinder, which is easy to replace but not included in the purchase. With a runtime of up to 5.6 hours, it provides reasonable use time for short-term heating needs. However, its heating capacity and coverage area might not be sufficient for larger greenhouses.

The heater is lightweight and portable, making it easy to move around as needed. Despite its many safety features, the requirement of a vent area for adequate ventilation and the prohibition of unauthorized accessories may limit flexibility in certain situations. Additionally, it is not suitable for use in moving vehicles or motorized settings. For those seeking an efficient, portable, and safe propane heater for small spaces, the Little Buddy offers good value, but be mindful of its limitations in heating larger areas.