225 CMR, § 22, § R408

R408.2.1 Revise the first sentence of Subsection R408.2.1 by replacing 95% with 90% to read as follows:

R408.2.1 Enhanced Envelope Performance Option. The total building thermal envelope UA, the sum of U-factor times assembly area, shall be less than or equal to 90% of the total UA resulting from multiplying the U-factors in Table R402.1.2 by the same assembly area as in the proposed building. The UA calculation shall be performed in accordance with Section R402.1.5. The area-weighted average SHGC of all glazed fenestration shall be less than or equal to 95 percent of the maximum glazed fenestration SHGC in Table R402.1.2.

R408.2.2 Delete option 1. of Subsection R408.2.2 and renumber option 2. As option 1., and option 3 as option 2.

R408.2.2 More efficient HVAC equipment performance option. Heating and cooling equipment shall meet one of the following efficiencies:

1. Greater than or equal to 10 HSPF/16 SEER air source heat pump.

2. Greater than or equal to 3.5 COP ground source heat pump.

For multiple cooling systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the cooling design load. For multiple heating systems, all systems shall meet or exceed the minimum efficiency requirements in this section and shall be sized to serve 100 percent of the heating design load.

R408.2.3 Delete option 1. of Subsection R408.2.3 and renumber option 2. As option 1., and option 3 as option 2.

R408.2.3 Reduced energy use in service water-heating option. The hot water system shall meet one of the following efficiencies:

1. Greater than or equal to 2.0 UEF electric service water-heating system.

2. Greater than or equal to 0.4 solar fraction solar water-heating system.

Notes

225 CMR, § 22, § R408

Adopted by Mass Register Issue 1485, eff. 12/23/2022.