10 Best Energy Efficient Space Heaters 2026 in the United States

The Rinnai EX38DTP is a propane-powered direct vent wall furnace designed to heat indoor spaces up to about 1600 square feet with a strong heating capacity of 36,500 BTUs. It uses advanced modulating technology to maintain consistent warmth without cold spots, which helps improve energy efficiency by adjusting heat output precisely to your needs. This makes it a smart choice for those looking to reduce fuel consumption and save on heating costs.

Safety is a key focus here, with features like a cool-to-the-touch cabinet and self-diagnostic electronics adding peace of mind, especially for families with children. Because it’s wall-mounted and fairly compact, it saves floor space and fits well in places like bedrooms, offices, or garages. Noise is reported to be minimal, contributing to a quiet heating experience.

The unit weighs over 100 pounds and is fixed to the wall, so it is not portable and not suitable if you want a heater you can easily move around. It also lacks smart home connectivity, which might be a downside if you prefer controlling your heater remotely via apps. This heater provides steady, efficient heat safely in a fixed installation, making it ideal for homeowners or renters who want a reliable, low-maintenance heating solution but don’t require portability or smart controls.

The Rinnai EX22DTP is a propane-powered direct vent wall heater that offers strong heating capacity at 20,700 BTUs, suitable for spaces up to around 1,600 square feet. Its advanced modulating technology helps maintain a consistent, comfortable temperature while avoiding cold spots, making it a good choice for bedrooms, home offices, or studies. The unit emphasizes energy efficiency by adjusting fuel use to match your heating needs, which can help reduce heating costs over time.

Safety is well-covered, featuring a cool-to-the-touch exterior and self-diagnostic electronics, which is reassuring for families with children. Noise-wise, it operates quietly thanks to its fan and forced-air heating method, contributing to a peaceful indoor environment. Being wall-mounted and compact, it saves floor space and fits nicely in modern homes, although at 67 pounds it’s not something you'd move around frequently.

While it lacks portability compared to plug-in heaters, its programmable thermostat and smart tech integration (including Wi-Fi compatibility) add convenience for personalized temperature control. Installation requires professional setup due to its propane fuel type and direct vent system, which may add upfront costs. If you want an energy-efficient, safe, and quiet solution for heating medium-sized indoor spaces and don't mind a fixed heater, the Rinnai EX22DTP is a solid option with strong warranties on parts and labor.

The Rinnai EX08DTN is a natural gas wall-mounted heater designed for indoor use, delivering 8,000 BTUs of heat which is suitable for spaces up to around 1,600 square feet like bedrooms or home offices. It stands out for its energy efficiency thanks to a 7-stage modulating gas valve and electronic thermostat that helps maintain temperatures between 60 and 80°F without wasting fuel. This model is quiet in operation, making it a good fit for areas where low noise is important.

Safety-wise, it features a cool-to-touch cabinet, child lock, and self-diagnostic systems that monitor performance and automatically shut down if issues arise, offering peace of mind especially in family homes. However, it requires professional installation due to its natural gas connection and venting needs, which adds to the initial cost and complexity compared to plug-in electric heaters.

The heater is wall-mounted and compact, making it space-saving but not portable, and is best suited for permanent placement. It comes with a strong warranty (10 years on the heat exchanger), reflecting Rinnai’s confidence in durability. If you’re looking for a reliable, energy-efficient gas heater for a fixed indoor space with quiet, safe heating and precise temperature control, this is a solid choice. Those needing a portable or electric option should look elsewhere.