I am modeling a building served by water source heat pumps, the first option was to serve the outside air by DOAS, an alternative design is introducing the OA directly to the WSHP. When I used the DOAS the outside air was delivered at a constant rate and fluctuates between the minimum OA and 0 based on the operation schedule of the DOAS as shown in the first image. However when the outside air is delivered directly to the WSHP it seems to fluctuate randomly and never reaches the minimum OA rate as shown in the second image, I was expecting the OA in this case to be constant 24/7 since there is no schedule governs the operation of the WSHP. Any ideas what is causing this?
Thank you,
