HVAC simulations

grasshopper honeybee
,
1

For one of my academic research topics, I was trying to simulate the performance of various HVAC systems:

1.natural gas furnace

  1. boilers

  2. PTAC

  3. Air source heat pumps.

I created a basic house model set in Philadelphia climate to compare the performance of the systems, but I came across a few doubts:

  1. The HVAC systems list does not contain a boiler option- so what is the best alternative to simulate this?
  2. The list also does not contain Air source heat pump, but I used VRF+DOAS with the heat rejection type to be air-cooled in cooling details_- is this the best way to simulate the Heat pump?
  3. The result for the VRF+DOAS showed that cooling loads for the Fall months to be quite high- higher than for the summer months- this is logically not right, so was wondering why this error would occur.
  4. All the outputs are in kWh- how is the conversion calculated for Natural gas?
  5. For the VRF+DOAS heating result- it gives multiple outputs (multiline data) but the cooling load is a single output?
    gh file
2

@Vid ,

I recommend using the new Ladybug Tools 1.0.0 that was just released last week. It has over 100 detailed HVAC templates and many of them are variations on the plant side of things, including swapping out boilers/chillers with ASHPs. Usually, when people say “air source heat pump” they are referring to something very different from a VRF. There’s also a big open question of what you are using to distribute the heat from the boiler or the ASHP (eg. are you circulating hot water generated by the boiler or ASHP through a baseboard system). Also, PTAC just refers to the AC and the heating with PTACs is usually done with a boiler and baseboard.

You can measure natural gas fuel energy in kWh; not sure what you’re asking here. You get multiple outputs for some of the detailed HVACs because there are multiple pieces of HVAC equipment consuming energy.

1 Like