Could you please provide some advice to the following case (the building belongs to System 7):
1. Proposed project is arranged with water cooled chillers and dry coolers (cooling towers of close type). They coolers were chosen because the chiller plant is supposed to operate at minus outdoor temperature conditions. Also following this approach there is a heat exchanger separating the dry coolers and condenser circuit, whereby the dry cooler loop is filled with a glycol/water mixture in order to prevent freezing.
2. The Baseline plant, as per app. G should have cooling tower. It has not been specified whether this cooling tower is of open or closed type and it has been prescribed a fix pump power value of 19 W/gpm.
The question is:
Should we model the Baseline also with dry coolers and glycol loop. There should be such option because in climate zones 6, 7 and eventually 8 and also by System 7, an open cooling tower will face problems and therefore a comparison between items 1. and 2. above will be made at not equal operating conditions.
You advice on the matter will be highly appreciated.