431.110—Energy conservation standards and their effective dates.
Each commercial storage water heater, instantaneous water heater, unfired hot water storage tank and hot water supply boiler 1 must meet the applicable energy conservation standard level(s) as follows:
Code of Federal Regulations
Footnote(s): 1 Any packaged boiler that provides service water, that meets the definition of “commercial packaged boiler” in subpart E of this part, but does not meet the definition of “ hot water supply boiler” in subpart G, must meet the requirements that apply to it under subpart E.
| Product | Size | Energy conservation standard a (products manufactured on and after October 29, 2003) b | |
|---|---|---|---|
| Minimum thermalefficiency | Maximum standby loss c | ||
| Electric storage water heaters | All | N/A | 0.30 27/Vm (%/hr) |
| Gas-fired storage water heaters | ≤155,000 Btu/hr>155,000 Btu/hr | 80%80% | Q/800 110(Vr) 1/2 (Btu/hr)Q/800 110(Vr) 1/2 (Btu/hr) |
| Oil-fired storage water heaters | ≤155,000 Btu/hr>155,000 Btu/hr | 78%78% | Q/800 110(Vr) 1/2 (Btu/hr)Q/800 110(Vr) 1/2 (Btu/hr) |
| Gas-fired instantaneous water heaters and hot water supply boilers | <10 gal≥10 gal | 80%80% | N/AQ/800 110(Vr) 1/2 (Btu/hr) |
| Oil-fired instantaneous water heaters and hot water supply boilers | <10 gal≥10 gal | 80%78% | N/AQ/800 110(Vr) 1/2 (Btu/hr) |
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Code of Federal Regulations
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| Product | Size | Minimum thermal insulation |
|---|---|---|
| Unfired hot water storage tank | All | R-12.5 |
| a Vm is the measured storage volume and Vr is the rated volume, both in gallons. Q is the nameplate input rate in Btu/hr. | ||
| b For hot water supply boilers with a capacity of less than 10 gallons: (1) the standards are mandatory for products manufactured on and after October 21, 2005, and (2) products manufactured prior to that date, and on or after October 23, 2003, must meet either the standards listed in this table or the applicable standards in Subpart E of this Part for a “commercial packaged boiler.” | ||
| c Water heaters and hot water supply boilers having more than 140 gallons of storage capacity need not meet the standby loss requirement if (1) the tank surface area is thermally insulated to R-12.5 or more, (2) a standing pilot light is not used and (3) for gas or oil-fired storage water heaters, they have a fire damper or fan assisted combustion. | ||