Zone VS Central

[bennyk]

I work for Energy management company and a rookie looking forward to head on this industry.

The building has VAV each floor. But for AH AC request on 1 floor , It takes on 5 floors at a time. It may be simple for folks , what would be the cheapest solution to reduce energy . Please suggest me.

[sysint]

VAV systems are typically more energy hogging especially if they have reheat. You may look into some case studies Trane did on lower temp systems with reduced fan requirements. Otherwise, you are better looking at a VFD if it has none and also ERV for the OA requirement.

I would also suggest reading up on VAV as you don't seem to understand it very well by your post. Search this site for Honeywell's Gray manual and that's a start.

[bennyk]

Thanks . I would for sure

[tlp261]

Does the air handling unit serve 5 floors? It has to run if any one VAV is requested on, so that could account for 5 floors having air supplied. The individual VAV's that are not requested on should remain at an Unoccupied setpoint though even if the AHU starts.

[bennyk]

One of the reason may be I am still lacking detail on the building. As the details I have received, It got 16 compressors at mid level plant room which supplies to 16 VAV each floor. But suprisingly it adds no vacant floor isolation. BMS used is TAC pacific Inet 7. My interest is " shouldnt it be possible to isolate floors ' without any change on hardware (extra bucks on hardware) , so only online floors get conditioned.

Sorry guys , I am amateur on this industry and trying really hard to move into it.

[tlp261]

Isolation can probably be done by commanding VAVs closed on unoccupied floors through any DDC system, but that may not have been a requirement of the original design.

[bennyk]

Thanks. That could answer 50% of my question.

[bennyk]

What Parameter would it look. If it is function of temperature on the floors , cant it be possible that equipment left ON would call cooling?. Or will it be time function?