Gas engine-driven heat pumps can be mounted on either the roof or ground for cooling and heating in residential or commercial applications. Blue Mountain Energy, Southwest Gas, and the U.S. Department of Energy developed the 10-ton propane engine-driven heat-pump rooftop unit, which will serve as a platform for additional propane-based, engine-driven, heat pump, power, and combined heat and power products.
Fact Sheet
Propane Engine-Driven Heat Pump 

• Auxiliary Propane Heaters on School Buses
• Docket 12070

Propane-fueled auxiliary heaters heat engine coolant and recirculate the heat to warm bus engines and interiors without idling the engine. Researchers explored the use of auxiliary propane heaters on school buses as a clean, low-cost alternative to diesel-fired auxiliary heaters or prolonged idling of the engine. Through this effort, researchers examined health benefits, characterized the market, and conducted a life-cycle cost analysis.
Fact Sheet
Propane Heaters for School Buses 

• Combined Heat and Power Applications
• Docket 10954, 10637

Combined heat and power systems provide heat and generate electricity with higher efficiency and lower emissions levels than conventional heating and power generation alternatives. Researchers have evaluated and demonstrated an engine-driven, propane-fueled power generation set and microturbine, addressed CHP market uncertainties, obtained market share data, and explored the fuel flexibility and system performance of a propane-fueled unit in comparison to a natural-gas-fired system.
Project Report
Propane CHP System Demonstrations at University of Maryland, Chesapeake Building 

• Gas Cooling Technologies Study
• Docket 11957

Propane-fueled cooling technologies efficiently reduce indoor humidity and cool indoor air. In this study, researchers assessed the current state of fuel-fired cooling technologies that can be used as propane-fired cooling systems, outlined the technical challenges to improving efficiency and cost, and suggested a course of development and demonstration.
Project Report
Assessment of [Propane Fired Gas Air Conditioning, Heat Pumping, and Dehumidication Technologies 

• Heat Pump Pool Heater
• Docket 10866

Propane heaters can warm pools and spas more quickly than electric heat pumps, and can maintain heat better in cold weather. Researchers developed and tested propane-fueled heat pump pool heater prototypes that produce 100,000 British thermal units of heat, completed a final heat pump design, and certified the unit’s safety.

• NovelAire Desiccant Dehumidifier
• Docket 12569, 11552

NovelAire’s ComfortDry 400 system is a propane-fueled desiccant dehumidifier that controls indoor humidity in a cost-effective and energy-efficient manner. As part of the development process, NovelAire thoroughly tested the system and quantified its market potential. NovelAire is working to commercialize the ComfortDry 400 through securing Energy Star certification, developing a marketer sales guide, and demonstrating 20 units in four states.
Fact Sheet
Improving Indoor Air Quality: Propane-Fueled Dessicant Dehumidifiers 

• Residential Integrated Space and Water Heating System
• Docket 11110, 10181

A residential integrated space and water heating system fueled by propane is a high-efficiency air distribution technology that offers increased cost and energy savings and meets the space requirements of HUD-code manufactured homes. Researchers developed specifications for a propane-fueled unit for water and space heating in manufactured homes, and estimated heating loads for homes of various sizes in three heating zones.
Fact Sheet
Combination Space/Water Heating Systems Fact Sheet

• Rinnai Tankless Heater System
• Docket 15213

The Rinnai Tankless Heater System is a propane-fueled combination heat pump and tankless water heater. Researchers tested the efficiency and performance of the Rinnai system and compared it to two standard electric heat pump/water heater systems of like capacity using realistic water heating and space heating laboratory simulations.

• Road Construction and Maintenance Study
• Docket 15208, 15207, 12201

Road construction and maintenance activities require a reliable and portable fuel source. For this study, researchers examined the technical and economic feasibility of using propane heat to assist in drying wet subbase in transportation earthwork projects, surveyed state highway agencies to identify markets using the hot in-place recycling method for road rehabilitation and reconstruction, and determined the feasibility of using propane for other transportation applications, including snow removal.
Project Report
Feasibility Study of Propane Utilization by Transportation Agencies Report

• TEMP-AIR Heat Treatment for Bedbugs
• Docket 12221

Propane-fueled heaters can serve as a non-chemical approach to controlling bedbug infestations in hotels, residences, schools, and hospitals. Researchers tested bedbug response to heat and heat transfer in mattresses to validate the efficacy of TEMP-AIR heat treatment process in killing bedbugs. Researchers also developed heat transfer models to determine if temperatures lethal to bedbugs can be achieved.
Project Report
Fundamental Research on the Efficacy of Heat on Bed Bugs and Heat Transfer in Mattresses Report