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LEED/ASHRAE 90.1 airsource heat pump min OA Temp

asked Nov 19

Greg Estep's avatar

updated Nov 19

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 Nov 20

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  ( Nov 20 )

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Asked: Nov 19

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Last updated: Nov 20 '24