Buildings currently account for 72% of the nation's electricity use and 40% of our carbon dioxide emissions each year, 5% of which comes directly from air conditioning. Current building cooling systems run on electricity and use synthetic fluids, leading to large energy consumption and greenhouse gas emissions. Thermally driven absorption heat pumps—which transfer heat energy from one location to another in a cooling and heating system—offer independence from electricity supply constraints because these technologies can be powered from the combustion of natural gas and solar and waste heat. In addition to providing efficient space cooling and heating, these heat pumps can heat water. However, development of these systems has been hindered by low energy efficiency and bulkiness—due to the limited sorption capacity of the adsorbent material—resulting in increased assembly time and high system costs.
Project Innovation + Advantages:
Pacific Northwest National Laboratory (PNNL) is designing more efficient adsorption chillers by incorporating significant improvements in materials that adsorb liquids or gases. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, an adsorption chiller has few moving parts and uses almost no electricity to operate. PNNL is designing adsorbent materials at the molecular level that have at least 3 times higher refrigerant capacity and up to 20 times faster kinetics than adsorbents used in current chillers. By using the new adsorbent, PNNL is able to create a chiller that is significantly smaller, has twice the energy efficiency, and lower material and assembly costs compared to conventional adsorption chillers. PNNL received a separate award of up to $2,190,343 from the Department of the Navy to help decrease military fuel use.
If successful, PNNL would produce a smaller, lighter, and cheaper air conditioning unit for commercial buildings.
Waste-heat or solar-heat-based air conditioning could reduce on the demand for fossil-fuel-based electricity and help strengthen U.S. energy security.
Finding efficient and cost-effective ways to incorporate waste heat into cooling systems in addition to sources like solar and natural gas could decrease fossil-fuel-based electricity use and harmful emissions from coal-burning power plants.
Widespread use of this technology could save consumers money on their energy bills by reducing the amount of energy required to cool homes and businesses.