Subject: Air Doors and Energy Savings

From: Thaddeus Ballantine <[email-masked]>
Date: 19 Oct 1995 04:25:38 GMT

We have been battling with a few of our clients over the use of air door 
for retail stores with winter design temperatures in the ASHRAE 99% of 
less than 30 degrees F.  Our client, through other consultants, states 
that this saves money by reducing infiltration.

The air doors are installed typically on two sets of two 3'0" doors so 
that we end up with two 72" air doors with 72" in length and 16KW of 
electric heat.  The doors are typically 3'0" byt 8'-0"

We feel that the best solution to cold climate conditions esp. in retail 
environment is to have a vestibule.  The vestibule would provide a 
stepped temperature transition between the exterior environment of -5F 
to say 40F and the 70F in the store. We also feel that the use of an air 
door might actually entrain more air into the space than may come in from 
normally temporarily open doors due to the velocity of the air created by 
the air doors.  

Has anyone done any research on this subject?  We do not believe 
manufacturere's statements regarding energy savings.  In addition the 
sound levelsl produced by these devices are generally above NC50.  
Such volume levels start to dramatically compete with the background 
music provided in stores.

-- 
Thaddeus Steven Ballantine
ENCON-Energy Conservation Company, Inc.
4940 El Camino Real
Suite 200
Los Altos, CA 94022
[email-masked]