Applied Four Pipe Fan Coil Measure and Pump Usage Seems Low, What may be accounting for this?

asked 2016-02-27 23:55:28 -0600

VictoriaEagen gravatar image

updated 2017-08-05 08:07:06 -0600

Applied Four Pipe Fan Coil Measure and Pump Usage Seems Low, What may be accounting for this? It should be noted that I modified Four Pipe Fan Coil to have cold/hot water loops instead of cooling tower/boiler/chiller. I also made the pumps continuous. Could it be that they are being counted as interior equipment? Could this also be due to not adding in water fixture units yet? Thanks.

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@VictoriaEagen, this post is very hard to reply to as we have no context. The first thing I would do is check that your zones are holding the setpoint because if they are then you know the four pipe fan coil is probably functioning correctly. Some more context on the magnitude of the pumping energy, pump head specified, building sqft, use type, etc. will also be helpful. Water fixtures shouldn't effect the pumping energy for a four pipe fan coil as it's almost certainly a closed loop that is used for space cooling.

pflaumingo gravatar image pflaumingo  ( 2016-02-29 17:56:38 -0600 )edit

I am working on a 5 story dormitory, used for residential purposes only (i.e. no large kitchens or workout facilities). There are two AHU's on the roof that bring fresh air into the zones. There are fan coils in each zone that condition the air. I applied the four pipe fan coil system, removed the boiler/condensing loop/cooling tower and replaces these things with domestic chilled/hot water. This seems to be functioning fine, despite a larger than expected amount of unmet cooling hours. The fans show up at about 6% of the usage and the pumps, only about 2%. I understand maybe changing

VictoriaEagen gravatar image VictoriaEagen  ( 2016-02-29 22:12:29 -0600 )edit

the fan autosized values/default values (i.e. airflow and efficiency) to the actual values may increase this. But I do not understand why the pumps would be so low. I feel like I am missing maybe another loop somewhere? I am sorry my questions may not be very direct, I have limited experience and am struggling to find the right questions to ask. The research I have done suggests maybe I am missing a service hot water transfer loop, but I cannot figure out how that gets integrated into my current setup, or to be honest, what that really entails in the open studio application. Thanks!

VictoriaEagen gravatar image VictoriaEagen  ( 2016-02-29 22:16:49 -0600 )edit