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Gas heat pump with variable speed compressor

asked 2015-03-05 15:01:19 -0500

rkbest's avatar

updated 2015-11-14 16:12:07 -0500

I am new to openstudio and just working on my first model to use a gasheatpump that has vapor compression operation with one external unit and multiple indoor AHU's. Can some one help me figure out how& which system to reflect the closest. The GHP i use are 16 TR with four scroll compressor for VRF operation.

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@rkbest, welcome! Add 'openstudio' and/or 'energyplus' (or whatever tool you are using) as a tag in future questions to help with email routing.

__AmirRoth__'s avatar __AmirRoth__  ( 2015-03-05 15:11:11 -0500 )edit

@rkbest, what makes it a "gas" heat pump? Is the compressor driven by a gas combustion, or is auxiliary heating coil a gas furnace?

Neal Kruis's avatar Neal Kruis  ( 2015-03-06 11:34:32 -0500 )edit

The compressor driven and IC engine that uses piped natural gas as fuel. Something like this

rkbest's avatar rkbest  ( 2015-03-06 14:47:03 -0500 )edit

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answered 2015-03-06 15:46:29 -0500

Archmage's avatar

updated 2015-07-14 05:47:34 -0500

I think you would want to use the regular VRF system and set the type of fuel to be natural gas in the outdoor unit. See the Input/Output reference for ZoneHVAC:TerminalUnit:VariableRefrigerantFlow and AirConditioner:VariableRefrigerantFlow. There is an input field called "Fuel Type" in the AirConditioner:VariableRefrigerantFlow object that can be used to model a gas powered VRF system.

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Is there any other tool which can model GHP and work with Energyplus.

rkbest's avatar rkbest  ( 2015-07-10 16:10:18 -0500 )edit

My system is VRF heatpump and does not provide heat recovery and simultaneous cooling/heating. My system is close to VRF system + VRF zone terminal. You suggested terminal unit and airconditioner:VRF are these same as my selection.

rkbest's avatar rkbest  ( 2015-07-23 15:08:19 -0500 )edit

yes, it appears so.

Archmage's avatar Archmage  ( 2015-07-23 16:54:30 -0500 )edit

By changing the Fuel type, can I have variable efficiency for the gas to energy conversion? What conversion Energyplus takes when the fuel type is natural gas for cooling or heating. Is it constant efficiency and can that be modified based on experience?

rkbest's avatar rkbest  ( 2015-07-30 16:43:26 -0500 )edit

It is not constant efficiency. The VRF model has a large number of performance curves that adjust capacity and efficiency of the system, you will have to look at the documentation.

Archmage's avatar Archmage  ( 2015-07-31 06:26:14 -0500 )edit

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Asked: 2015-03-05 15:01:19 -0500

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Last updated: Jul 14 '15