Dear list, I have been asked to model a package of ECM's that include both air side and water side economizers. The model utilizes PSZ air side system with Dx cooling via water cooled condensers. Are these two types of economizers mutually exclusive? Can water side economizers be modeled without the presence of a chiller to bypass?
Thanks, Jacob
The technologies are technically mutually exclusive as there is no reason to have both as they generally perform the same function.
You don't have to have a chiller connected to a water side economizer. Just make sure to shut off the chilled water pump when the water side economizer isn't able to meet the load.
That said, if you're putting in a chilled water loop, a condenser loop, pumps, and a cooling tower, then you might as well buy a chiller and avoid buying the DX units. Unless of course you're using a dry cooler as your water side economizer. Even then you'll have a cooling coil with water and a cooling coil with DX. That will increase the pressure drop and consequently the fan power.
In reality it would be simpler to have a DX unit with an air-side economizer or a chiller with a water side economizer as it's the least amount of equipment to install and maintain.
Hope that makes sense.
Comments
@jakestrick please tag the modeling tool you plan on using so that users can better answer your question