[bldg-sim] Make-up air systems and heat recovery

Mike Tillou miket at etcgrp.com
Sat Aug 27 17:59:53 PDT 2005

As an aside to what Jeff Hirsch has said about this subject.

I have had good success creating an hourly schedule (8760 individual
hours) of type multiplier that can be used to adjust a process load at
the zone level to account for the effect of an ERV on a fan coil, heat
pump or other zone based system.  Using schedule type multiplier allows
you to adjust for both heating and cooling.  

It takes a little work.  The steps involved are: 1. export the necessary
variables via an hourly report 2. import them into Excel or other
spreadsheet, 3. do the necessary calculation, 4. normalize the results
to the largest value 5. write VBA macros (or do it by hand - Yikes!!.)
to do most of the work creating the hourly schedule of normalized
values, 6. past the schedule into the DOE2.2 input file, 7. use the
largest value as the actual process load and assign the hourly schedule
to adjust the load.  The hardest part is making sure that the schedule
you create matches the calendar year you are simulating. 

I don't know if you could figure out a way to do this for a dedicated
outside air system. It may work if you assign the hourly process load to
the dummy zone served by the dedicated OA system.  The OA passed to the
referenced system might pick up the load.  

If you are careful to account for the various interactions and use a
good calculation methodology you should get a reliable answer.       

Good luck,


Michael Tillou, PE
etc Group, Inc.
PO Box 7, Williamstown, MA 01267
ph. (413) 458-9870 fx. (413) 458-9875


You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 

More information about the Bldg-sim mailing list