eQUEST_4-Pipe FCU system with ASHP(heating) and chiller(cooling)
Dear all,
I am modelling a hotel with system through eQUEST as below,
•System: 4 -pipe FCU with seperate OA induction (dummy zone has been built to model the OA induction unit) •Heating source: air source heat pump •Cooling source: water cooled chiller
I encountered two problems:
1.As the ASHP can only be constructed in water side by selecting a chiller type as heat pump and attached to a 2-pipe circulation loop. I found that ASHP is supporting both heating and cooling for the building though the cooling source has been selected as chilled water loop at air-side. This does not comply with the design intention and do no good for energy conservation since the chiller has higher COP than the ASHP.
2.Another problem is that the 2-pipe circulation loop lead to some overheating unmet hours during winter when there is both heating and cooling load, even the system itself is a 4-pipe one.
I tried to set the heating and cooling schedule for the heat pump loop but somehow it gives me a 99.99% unmet when I turn off the cooling for heat pump loop. Only certain load is charged from the chilled water loop though the chiller capacity is autosizing at present...
I m totally stuck here, and wondering if anyone got any experience like this? any tips or advice is much appreciated, thanks in advance!
Allison
