Choosing Baseline HVAC-System in climate zone 1b

Johannes Hopf

LEEDuser Basic Member

2 thumbs up

October 23, 2012

Hi, 90.1-2007 confuses me a little. Our project (4 story, 9000 m²/90000 ft²) is located in climate zone 1b. The proposed building is heated by an electrical heatpump. There is no fossil fuel source. Is the baseline system system 5 or system 6? I would chose system 6 "electric resisstance". Right? The other point is, that G3.1.2.6 Economizer requests one for system 3-8. Table G3.1.2.6A recommends no economizer for climate zone 1 b. Table G3.1.2.6B instead list a shut-off-temperature. Do I need to model an economizer? Probably there is an error in the table, because all climate zones in table A are moist (a) and all climate zone in table B are either dry (b) or marine (c). Thanks a lot! Johannes

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Tue, 10/23/2012 - 13:43

If the building's heat source is electric use system 6. Correct. You do not need to model an economizer in the baseline in climate zone 1B. The prescriptive requirements in Section 6 do not require an economizer in 1B and the User's Manual is consistent with Table G3.1.2.6A. I could not find anything in an errata or interpretation correcting the inconsistency in the tow tables so I would also assume it is an error.