Modeling Indirect-Evaporative Cooling with Winter Heat Recovery

edit

I've modeled this before using OpenStudio. OpenStudio 1.5 or later offers a lot of flexibility by allowing direct or indirect evaporative coolers to be placed on the outdoor air exhaust/supply nodes. One option would be to place an indirect evaporative cooler on the supply node along with a HX coupling the exhaust and supply air streams. Another option would be to place the direct evaporative cooler on the exhaust stream with a sensible HX.

If you want to model a direct/indirect evaporative cooling system you could place a direct evaporative cooler on both air streams and couple the streams with a sensible HX. There is a measure that automates this available through the BCL.

For the indirect/direct evaporative cooling objects you can specify sensible and latent effectiveness's respectively. For the air to air HX you can specify both a sensible and latent effectiveness at various airflow rates for heating and cooling.

I have modeled indirect evaporative cooling in the VE before. My system had two stages of evaporative cooling on the exhaust side that then runs through a heat exchanger. I ended up having to model the evaporative cooling with cooling coils rather than the spray chamber component. The possible controlled variables for the spray chamber were too limited. I controlled the cooling coils via heat transfer using the value from the manufacturers materials for each stage. I used an 80% sensible effectiveness for the heat exchanger. The cooling coil controls staged on and off based on the supply side leaving DBT off the heat exchanger. I hope this helps even though it's a bit late.