VVT vs VAV
VVT vs VAV
(OP)
Is a VAV system better than VVT system ? Which is more expensive ? What are the advantages/disadvantages? I have a new single level office building (offices, lockers, meeting rooms, computer room, lunch room. Total 6000 sq ft) to design in the west coast.
thanks in advance.
thanks in advance.





RE: VVT vs VAV
With the VVT system the zones vote on what the RTU is doing (heat/cool or ventilate), so there may be times (depending on the similarity of zones) where the space has no airflow to avoid overheating or overcooling. If most of the zones on the RTU have similar exposures then the VVT system will likely not cause the RTU to "flip-flop" between settings.
With the VAV system your air handling unit will have some means of providing a variable air volume, with a relatively constant discharge air temperature (depending on the control strategy you may reset the discharge temperature to ensure higher air volumes in the zones). The VAV terminals will adjust from Max to minimum depending on space demand. Your system may have reheat or not (or perimeter radiation for heating).
In either case your computer room may have a separate cooling system to avoid high cooling demand on the system.
Eg.VVT Zone-All see http://www.zoneall.ca/
RE: VVT vs VAV
On heating, you're stuck heating rooms requiring cooling.
RE: VVT vs VAV