Public Housing Energy Conservation Clearinghouse: ECMs: Replace Inefficient Water Heaters

ECM: Domestic Water-Heating Systems

W5. Replace Inefficient Water Heaters

Description

Usually, a water heater is replaced only when it fails. But if the existing water heater is at least ten years old, it is near the end of its useful life, and it may make sense to replace it before it fails. By replacing the water heater before it stops working, the PHA may enjoy significant energy savings, in addition to avoiding a situation in which residents are without hot water while a new system is being selected. Replacing old, oversized water heaters generally yield higher savings than if the system is old but appropriately sized. In any case, if the old water heater is leaking or shows signs of heavy rust or water streaking in the combustion chamber, it should be replaced.

Applicability

Single-family and multifamily buildings with old, inefficient water-heating systems

Types

Individual tank
- gas
- electric
Central
- gas
- oil

Considerations

Energy efficiency can be compared on each unit by the EnergyGuide labels on the tank.
Consider the Energy Factor (EF) and the First Hour Rating (FHR).
When selecting a new hot water heater, an experienced professional should be consulted.
Water heaters should be appropriately sized to ensure adequate hot water and minimal energy waste.
Select models with a minimum of R-16 internal insulation.
Where electricity is relatively expensive compared to gas, the PHA may wish to consider switching to gas during replacement.

Performance/Economics

Replacing a conventional gas-fired central water heater with a high-efficiency condensing water heater saves approximately 28 percent.

Resources/Links

Selecting a New Water Heater, Part of the U.S. Department of Energy's Consumer's Guide. Discusses water heater types, considerations for selection, and costs.

Energy Conservation for Housing – A Workbook, HUD, September 1998. Pages 7-109 through 7-112 address replacing inefficient water heaters.

Energy Performance Contracting for Public and Indian Housing: A Guide for Participants, HUD, February 1992. Pages 26 and 27 address replacing inefficient water heaters using performance contracting.

Improving Energy Efficiency in Apartment Buildings, American Council for an Energy-Efficient Economy, 1995. ISBN 0-918249-23-6. Pages 104 through 115 address replacing inefficient water heaters.

Consumer Guide to Home Energy Savings, American Council for an Energy Efficient Economy, 1999, ISBN 0-918249-38-4. Chapter 6 addresses replacing inefficient water heaters.

CAUTION STATEMENT

TURN OFF UTILITIES: Turn off electricity, gas, propane, and other utilities before starting repairs, cleaning, or installations to avoid accident or injury.

BE AWARE OF LEAD-BASED PAINT HAZARDS: Many residences built before 1978 have paint that contains lead, which can pose a serious health hazard if paint, chips, and dust are not handled properly. See the U.S. Environmental Protection Agency (EPA) lead brief before disturbing painted surfaces in homes of this vintage. Follow the HUD "Lead-Safe Housing Rule" for requirements for notification, evaluation and reduction of lead-based paint hazards.

BE AWARE OF ASBESTOS HAZARDS: Homes older than 1977 may have building products that contain asbestos such as insulation, high-temperature gaskets, roofing and siding shingles, and vinyl sheet flooring. See the EPA asbestos brief before disturbing such materials.

BE AWARE OF MOLD AND MOISTURE HAZARDS: Molds can gradually destroy materials they grow on; can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people; can cause asthma attacks in people with asthma who are allergic to mold; and can cause other serious health problems. To learn more about preventing and cleaning up mold in homes, see these mold guides and the EPA brief on What to Wear When Cleaning Moldy Areas.