Setting COP for Heating and Cooling systems

grasshopper honeybee
1

Hello,

With honeybee legacy it was very easy to change the COP of the heating and cooling systems using the “HeatingDetails” and “CoolingDetails” components. Is there a way to similarly change the COP with honeybee 1.1.0? Is there a way to customize and see the parameters in the HB HeatCool HVAC templates?

Thanks!
-Teresa

2

Hi @t_pnw ,

You can still change several of the “high level” parameters on the detailed HVAC templates, like the economizer type and heat recovery. While I know that we supported it in legacy, just changing the rated COP of a piece of HVAC equipment is usually not the best practice as you should probably also be changing the curves that define the performance of that piece of equipment to reflect why it has a better COP. This type of curve-editing (alongside the rated COP) can be done with Ironbug, which you can use both with Legacy and with LBT via the workflow here.

For which HVAC template are you trying to edit the COP and do you have a sense of why the COP is better for the equipment you are trying to model?

3

Hi @chris,

Thanks for your response!

I am modeling a tiny house (1 zone) that will likely use a ductless heat pump for heating and cooling. I wanted to run simulations with and without a heat recovery ventilator, so I was thinking of using these templates:

  1. Residential heat pump (to simulate w/out the HRV)
  2. DOAS with VRF (to simulate w/ the HRV)

I am having a hard time finding the default specs/parameters of these templates, could you point me in the right direction? I was thinking of modeling a few different heat pump models, which is why I am interested in changing efficiency parameters.

Thanks again,
-Teresa

4

Hey @t_pnw ,

You’re welcome!

Modeling a DOAS for a tiny house might be a bit overkill as the template DOAS systems are connected to full heating and cooling plants with hot/cold water loops. If you really wanted to go that route, you could use district chilled/hot water to try to externalize the heating + cooling but most small residences would probably have enough exterior area (and corresponding infiltration) that a dedicated ventilation system is probably not necessary unless you are going full Passivhaus. So you can just use the VRF template (without the DOAS).

Most of the default efficiencies for equipment in the HVAC templates comes from ASHRAE 90.1 but, if you are looking to understand how the HVAC system is set up, nothing compares to opening the OSM file in the OpenStudio Application and going to the HVAC and/or the Thermal Zones tab. There, you can see what all of the loops and equipment are and check the various equipment parameters.