Keith D. Robinson, P.E.
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There are new regulations that affect any facility that may have combustible dust. What do you need to do to comply with these new combustible dust regulations? Keith D. Robinson, P.E. will present a series of talks that will help outline these new regulatiosn and how they affect you.


The System Curve, The Fan Curve, and The Operating Point

Ever wonder how fans and duct systems interact? I will be presenting a complimentary Lunch and Learn session on April 21, 2016 entitled "The System Curve, The Fan Curve, and the Operating Point". Learn the theoretical background and then take measurements on a fan system. Space is limited. Contact me at for more details and to reserve your spot. 


Is Air Changes per Hour (ACH) a valid ventilation design parameter?

One question discussed at the recent ASHRAE Winter Meeting in Orlando was whether or not Air Changes per Hour, commonly referred to as ACH, represents a valid design criterion for ventilation systems. There are several design standards that prescribe minimum ACH rates to keep contaminant levels at acceptable levels. In general, it is considered that the best way to decrease exposure to chemicals and pollutants in the indoor environment is to increase the ACH. However some research now suggests that increasing the ACH actually increases exposure rather than decreases exposure. Increasing ACH also increases the energy usage of the system due to fan energy and the need to heat or cool the incoming makeup air. So is this a valid method to use when designing ventilation systems?

The answer is an unqualified "Maybe." Each system and situation is different. Some situations, such as labs with fume hoods, need relatively still air to prevent recirculation of pollutants form entering the operator's breathing zone. Other situations, such as machinery rooms, need large amounts of air to evacuate potentially hazardous gasses if a leak occurs. Suffice it to say that it takes sound engineering judgment in cooperation with the Environmental Health and Safety (EH&S) department during the design phase to ensure that the correct design criteria are used for each specific system.


Understanding and Using ANSI/AIHA/ASSE Z9.2-2012

Keith D. Robinson, P.E. will be teaching a course entitled PDC 109:  Understanding and Using ANSI/AIHA/ASSE Z9.2-2012 at the upcoming AIHce conference. This course is intended for Environment Health & Safety (EH&S) personnel, facility managers, system operators, and engineers. 



Keith D. Robinson, P.E. • 4966 Daybreak Cir • Colorado Springs, CO 80917 • 303-746-8904