ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Engineering III Building
40,000 gsf
Completed 2002
Designed and constructed
in two phases due to budget
limitations
Phase I Engineer:
Affiliated Engineers
Walnut Creek
Phase II Engineer:
Brummell Myrick
San Luis Obispo
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Project Phasing
Phase I:
Building shell
Major equipment
Main supply/return/exhaust ductwork
Phase II:
Interior finishes
Terminal units & zone ductwork
Controls
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Differences in Design Approach
Building systems:
VAV reheat system
2 AHU’s
Offices and labs – heating, cooling, and economizer
 Shop spaces – heating only, 100% outside air

Constant volume fume hoods, variable volume exhaust
Phase I designer approach:
Common exhaust system serving all lab fume hoods
Makeup air damper on exhaust fan to ensure minimum stack velocity
Phase II designer approach:
Concerned about fume hood chemical compatibility
Separate dedicated exhaust fans for each fume hood
Results in main exhaust fan being oversized
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Phase I Design - System Schematic
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Phase II Design - System Schematic
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Project Goals
Convert constant volume fume
hoods to VAV
Develop project proposal, scope of
work, plans, and new sequences of
operation
Calculate project cost, energy
savings, and payback
Obtain utility rebates from PG&E
and So Cal Gas
Propose to campus, and get
approval for necessary funding
Install and commission
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Design Issues to be Evaluated
Leave hoods on dedicated fans or
reconnect to main exhaust system?
Are all materials used in hoods
chemically compatible and safe to
mix?
What is the best control approach?
Aircuity vs. Siemens? Pheonix valves
vs. butterfly valves?
Are there any other operational or
commissioning issues that need to be
resolved?
Evaluate capital cost, payback, and
life cycle cost of each option.
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Next Steps
Building tour next week – Thursday Jan 14 at 11:00 – meet in Eng III
courtyard
Study building plans and sequences of operation
Talk to building technician, lab users, and EH&S about hood user needs
and chemicals used
Talk to building engineers about building operational issues regarding
temperature control, building pressurization, maintenance issues
Determine analysis and design tasks that are necessary
Survey system, record equipment data, take measurements
Organize teams and delegate tasks
ASHRAE Club Project
VAV Fumehood Retrofit - Engineering III Building
Resources
Building plans:
http://www.afd.calpoly.edu/facilities/maps_eplanroom.asp?pid=7
HVAC zoning and locations of equipment:
http://www.afd.calpoly.edu/facilities/maps_floorplans.asp?pid=7
Facility Services
Brummel Myrick Engineers
Rumsey Engineers
George Yardley Company (Aircuity and Phoenix)
Siemens