Hospital interstitial space
Hospital interstitial space
(OP)
I am currently working on a renovation in a hospital, original design from the 70's. I'm taking over design from a prior mechanical enegineer, as the HVAC portion has failed. This design included taking substantial amounts of supply and return air from the interstitial space. The interstitial space has supply and return from four different AHU's on the floor, and rebalance of all four units is not within the contracted scope.
I am not familiar with any criteria, ICC, ASHRAE, AIA, etc, that dictates the amount of air to and from the interstitial space, other than common sense need for moisture control. Interstitial is obviously different than mechanical, not included in ASHRAE 62.1-2007 for allowable recirculation. Any recommendations or criteria source that can be provided would be greatly appreciated.
I am not familiar with any criteria, ICC, ASHRAE, AIA, etc, that dictates the amount of air to and from the interstitial space, other than common sense need for moisture control. Interstitial is obviously different than mechanical, not included in ASHRAE 62.1-2007 for allowable recirculation. Any recommendations or criteria source that can be provided would be greatly appreciated.





RE: Hospital interstitial space
The IMC Chapter 4 gives you minimum outside air requirements that the plenum could supply for each air handler and the exhaust plenum can be used for relief air to keep the building slightly positive and prevent exterior doors from standing open.
Don Phillips
http://worthingtonengineering.com
RE: Hospital interstitial space
Given the fact that the interstice space carries a number of other services, I'd sure want avoid using the space as any kind of open air plenum which might mix air to/from the occupied spaces below, and would likely want to keep it at a slight nagative air pressure to insure that any leaks of services (med gases, plumbing) are contained within the interstice space, and not able to contaminate the clean occupied spaces below.
RE: Hospital interstitial space
Don Phillips
http://worthingtonengineering.com