Dear all,
we’re currently involved in the LEED v4 Core & Shell certification of a new office building. This building will have a central HVAC system serving both common areas and tenanted spaces, that includes central AHUs providing ventilation and chillers/heat-pumps providing chilled water and hot water. Insided the tenant spaces, future occupants will have to install their own fan-coils at the time of the fit-out.
As the tenant fan-coils will not be installed in the Core & Shell scope of works, for purposes of energy simulation these equipment shall be considered with efficiency levels similar to baseline. However, the baseline system for this building does not have fan-coils (HVAC system type 8 – AHUs + FPBs). In this case, we are using the specific fan power considered in fan-powered boxes (0,74 W/(l/s)) to model the fan-coils fan power in proposed building. Do you validate this approach?
Tyler Thumma
7GroupLEEDuser Expert
60 thumbs up
December 16, 2022 - 8:11 am
No, the specific fan power should not be based on the allowance for fan-powered VAV boxes. If the tenant systems are modeled as fan coils, they should be modeled as constant volume using the fan power allowance for System Types 3-4 from Section G3.1.2.10. Another option would be to model the Baseline air-side system with chilled water and hot water supplied by the designed chillers/heat pumps and ventilation still supplied by the central AHUs.