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1323.0780 TABLE 7.8, PERFORMANCE REQUIREMENTS FOR WATER HEATING EQUIPMENT.

ASHRAE Standard 90.1, Section 7, Table 7.8, is amended to read:

TABLE 7.8 Performance Requirements for Water Heating Equipment

Equipment Type Size Category (Input) Subcategory or Rating Condition Performance Requireda
Electric Water Heaters ≤12 kW Resistance ≥20 gal 0.97-0.00132V EF
>12 kW Resistance ≥20 gal 20+35 √V SL, Btu/h
≤24 Amps and ≤250 Volts Heat Pump 0.97-0.00132V EF
Gas Storage Water Heaters ≤75,000 Btu/h ≥20 gal 0.67-0.0019V EF
>75,000 Btu/h <4,000(Btu/h)/gal 80% Et(Q/800+110 √V) SL, Btu/h
Gas Instantaneous Water Heaters >50,000 Btu/h and <200,000 Btu/h ≥4,000(Btu/h)/gal and <2 gal 0.67-0.0019V EF
≥200,000 Btu/hc ≥4,000(Btu/h)/gal and <10 gal 80% Et
≥200,000 Btu/h ≥4,000(Btu/h)/gal and ≥10 gal 80% Et(Q/800+110 √V) SL, Btu/h
Oil Storage Water Heaters ≤105,000 Btu/h ≥20 gal 0.59-0.0019V EF
>105,000 Btu/h <4,000(Btu/h)/gal 78% Et(Q/800+110 √V) SL, Btu/h
Oil Instantaneous Water Heaters ≤210,000 Btu/h ≥4,000(Btu/h)/gal and <2 gal 0.59-0.0019V EF
>210,000 Btu/h ≥4,000(Btu/h)/gal and <10 gal 80% Et
>210,000 Btu/h ≥4,000(Btu/h)/gal and ≥10 gal 78% Et(Q/800+110 √V) SL, Btu/h
Hot Water Supply Boilers, Gas and Oil ≥300,000 Btu/h and <12,500,000 Btu/h ≥4,000(Btu/h)/gal and <10 gal 80% Et
Hot Water Supply Boilers, Gas ≥4,000(Btu/h)/gal and ≥10 gal 80% Et(Q/800+110 √V) SL, Btu/h
Hot Water Supply Boilers, Oil ≥4,000(Btu/h)/gal and ≥10 gal 78% Et(Q/800+110 √V) SL, Btu/h
Pool Heaters Oil and Gas All 78% Et
Heat Pump Pool Heaters All 4.0 COP
Unfired Storage Tanks All R-12.5

aEnergy factor (EF) and thermal efficiency (Et) are minimum requirements, while standby loss (SL) is maximum Btu/h based on a 70° F temperature difference between stored water and ambient requirements. In the EF equation, V is the rated volume in gallons. In the SL equation, V is the rated volume in gallons and Q is the nameplate input rate in Btu/h.

bInstantaneous water heaters with input rates below 200,000 Btu/h must comply with these requirements if the water heater is designed to heat water to temperatures 180° F or higher.

Statutory Authority:

MS s 326B.02; 326B.101; 326B.106; 326B.13

History:

33 SR 1473

Published Electronically:

June 17, 2009

Official Publication of the State of Minnesota
Revisor of Statutes