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LEED/ASHRAE 90.1 airsource heat pump min OA Temp

asked 2024-11-19 10:54:20 -0600

Greg Estep's avatar

updated 2024-11-19 13:48:05 -0600

Hello all, I can't find the baseline minimum outdoor air temperature for DX heating coils? At what temperature should I cut out the compressor and have the electric resistance heating coil take over?

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answered 2024-11-20 13:04:20 -0600

Petros Dalavouras's avatar

Are you referring to Baseline modeling e.g. systems 2 and 4? If yes, according to G3.1.3.1 it is 4oC. However, if you are going for LEED 4.1 thus 90.1-2016, then they added that the heat pump needs to keep operating when the electric resistance operates.

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Hi thank you so much for your response. I'm working on LEED v4.0, which is ASHRAE-2010. Yes, the baseline is system 2 and 4. Section G3.1.3.1 has changed. In the 2010 version it says,

G3.1.3.1 Heat Pumps (Systems 2 and 4). Electric air-source heat pumps shall be modeled with electric auxiliary heat. The systems shall be controlled with multistage space thermostats and an outdoor air thermostat wired to energizeauxiliaryheatonlyonthelastthermostatstageandwhenout-door air temperature is less than 40°F.

Greg Estep's avatar Greg Estep  ( 2024-11-20 13:36:34 -0600 )edit

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Asked: 2024-11-19 10:54:20 -0600

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Last updated: Nov 20