System Balancing

[globe trekker]

Greetings to everyone!

I have a "new" medical clinic type facility in the plan review stage. On the plans, in each

restroom the plans show a postive pressure rather than a negative pressure (i.e - there

is more Supply Air coming in to each room than there is Exhaust Air going out).

QUESTION # 1: Is there somewhere in the IMC or the IECC, or ASHRAE 90.1 that

requires the system to be balanced (equal air in, ..equal air out), or as I have been taught,

in the restrooms, there should be a negative pressure effect (a vacuum effect) so as to

effectively remove any noxious odors?

As usual, no RDP has designed these submittals.

Thanks for your input!

.

 

[Gregg Harris]

Greetings to everyone!I have a "new" medical clinic type facility in the plan review stage. On the plans, in each

restroom the plans show a postive pressure rather than a negative pressure (i.e - there

is more Supply Air coming in to each room than there is Exhaust Air going out).

QUESTION # 1: Is there somewhere in the IMC or the IECC, or ASHRAE 90.1 that

requires the system to be balanced (equal air in, ..equal air out), or as I have been taught,

in the restrooms, there should be a negative pressure effect (a vacuum effect) so as to

effectively remove any noxious odors?

As usual, no RDP has designed these submittals.

Thanks for your input!

.

Just as in your bathroom scenario for negative along with lockerrooms etc. In medical applications certain rooms are required to be positive to keep contaminants out of the space.

 

[Dr. J]

IMC 501.3

"... Where mechanical exhaust isrequired in a room or space in other than occupancies in R-3

and dwelling units in R-2, such space shall be maintained with a

neutral or negative pressure. If a greater quantity of air is supplied

by a mechanical ventilating supply system than is

removed by a mechanical exhaust for a room, adequate means

shall be provided for the natural or mechanical exhaust of the

excess air supplied. ..."