ASHRAE Golden Gate Chapter

OCTOBER 2011 DINNER MEETING

Why Enthalpy Economizers Don't Work
Steve Taylor, PE, Taylor Engineering
Thursday, October 13 (5:30 pm to 9:00 pm)
Scott's Seafood, Jack London Square, Oakland (map & directions)

Agenda:

	5:30 pm		Registration and Social Hour
	6:30 pm		Dinner, Announcements and Introductions
	7:45 pm		Break
	8:00 pm		Main Program
	9:00 pm		Adjourn

Speaker(s):

Steve Taylor, PE, Taylor Engineering
Steve Taylor is the principal of Taylor Engineering, Alameda, CA. He is a registered mechanical engineer specializing in HVAC system design, control system design, indoor air quality engineering, computerized building energy analysis, and HVAC system commissioning. Mr. Taylor graduated from Stanford University with a BS in Physics and a MS in Mechanical Engineering and has over 30 years of commercial HVAC system design and construction experience. He was one of the primary authors of the HVAC sections of ASHRAE Standard 90.1-1989 and 1999 “Energy Conservation in New Non-residential Buildings” and California’s Title 24 Energy Standards and Ventilation Standards. Other ASHRAE project and technical committees Mr. Taylor has participated in include Standard 62.1 Indoor Air Quality (chair), ASHRAE Standard 55 Thermal Comfort (member), Guideline 13 Specifying DDC (chair), Guideline 16 Economizer Dampers (chair), TC 1.4 Controls (chair), and TC 4.3 Ventilation (vice-chair). He is immediate past vice-chair of the USGBC LEED Indoor Environmental Quality Technical Advisory Group, a member of the CSU Mechanical Review Board, and a member of the IAPMO Mechanical Technical Committee administering the Uniform Mechanical Code.

Presentation
Summary:

Why Enthalpy Economizers Don’t Work
The topic includes a discussion of how economizer high limit controls work theoretically and how they work in practice including sensor error. Our energy simulations conclude that differential enthalpy economizers will never work better than a simple outdoor air drybulb switch in any climate even if extremely accurate sensors are used and maintained in calibration. I conclude with recommendations for what type of high limit devices should be used and what their setpoints should be in each ASHRAE and California climate zone.

Download Presentation (6.4mb PDF)