SPACE COOLING

This 2004 guide by the Rocky Mountain Institute (RMI) provides homeowners with strategies to reduce space cooling costs and energy use. It advocates for a hierarchical approach: first minimizing heat gain through passive measures, then utilizing low-energy ventilation, and finally selecting the most efficient mechanical cooling systems based on climate and budget.

• Space cooling and heating represent 45 percent of total home energy use, costing a typical family $677 annually. Space cooling alone typically accounts for 13 percent of total energy use, costing $197 per year, though in hotter climates this can exceed 20 percent of energy use and cost more than $350 per year.
• Passive cooling measures—which control heat gain without electrical equipment—can reduce energy bills by up to 40 percent. Effective measures include natural ventilation, minimizing indoor heat generation, weatherization, insulation, window shading/glazing, roof whitening, attic ventilation, and strategic landscaping.
• Fans are presented as a low-cost cooling option. Ceiling fans can allow homeowners in hot climates to raise their thermostat by as much as 4ºF while maintaining comfort. Whole-house fans are described as a cost-effective method for moderate climates, though they can cause dangerous backdrafting from combustion appliances if there is insufficient ventilation.
• Evaporative coolers are highly efficient in dry climates, using less than one-quarter of the energy of conventional air conditioners. However, they are ineffective in humid climates, such as most eastern U.S. states and much of the Midwest. They can increase annual water bills by $15–20, using between 3.5 and 10.5 gallons of water per hour.
• Geothermal heat pumps are more efficient than air-source heat pumps, using 23–44 percent less energy. According to the EPA, they can save homeowners 20 to 50 percent in cooling costs and 30 to 70 percent in heating bills, potentially totaling over $400 in annual savings.
• Conventional air conditioning is often the most expensive and energy-intensive cooling method. Efficiency can be improved by sealing ducts (saving up to $300 annually), setting thermostats to 78ºF or higher (each degree below increases consumption by 8 percent), and raising the thermostat by 10–15ºF when away to save 5–15 percent on bills.

APA

Yardi, R., Smith, A., & Wang, K. (2004). SPACE COOLING. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB3SpaceCool.pdf

Chicago

Yardi, Ramola, Andy Smith, and Katherine Wang. SPACE COOLING. RMI, 2004. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB3SpaceCool.pdf.

Wikipedia

{{cite report |last1=Yardi |first1=Ramola |last2=Smith |first2=Andy |last3=Wang |first3=Katherine |title=SPACE COOLING |publisher=RMI |date=2004 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB3SpaceCool.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{yardi2004space, author = {Yardi, Ramola and Smith, Andy and Wang, Katherine}, title = {{SPACE COOLING}}, institution = {RMI}, year = {2004}, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB3SpaceCool.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }