Total Building Commissioning

I received some feedback from a reader, Daryl,  the other day that was great and I’d like to share it with you.

From Daryl…

I would like to talk about HVAC air flow engineering with you some just for fun. I have some text book errors to share with you.

I am an end user in the science field but with a strong mechanical background in a new California College with 4 small labs and a hall which is used as a prep area that divides the four rooms.

I disagree with using diversity in an educational setting. Maybe in a research lab but not in an educational setting. Why? Because we have a 3yr old lab in which diversity was used and we have rooms that are stuffy and fume hoods that do not work because the engineer figured only some of the fume hoods would be used only some of the time. Now the exhaust fans are undersized along and the air handler is too small.

Check this out. I was looking above the ceiling tiles and noticed that each room has its own exhaust fan to serve the fume hoods in that room which is good. Here is the bad part. They installed a smoke fire damper in each fume hood exhaust system which is a major mechanical code violation the Nation over correct? If students ever make smoke in one of the fume hood the system will see this as a fire and slam the damper shut.  Then the room will have to be evacuated for sure and the ducting on the other side of damper could collapse due to extreme and excessive exhaust fan static pressure.

Here is another short cut I do not like to see in building HVAC engineering. Using the space above the ceiling tiles as the return plenum. Yes it saves $$$$ by not having to duct return air, but the removal of heat is very poor and because of the tremendous static pressure it takes to try to pull the return air back to air handler.

Here is one more winner that I see. The air handler on the science building was not specified as a 100% outside air make up unit. Thus every winter the complete filter bank freezes up solid. As you know science buildings are special, air cannot ever be recycled or returned.

Thanks for sharing Daryl.

Feedback from building users, such as Daryl,  is invaluable and we can improve our delivery to our clients if we will just sit down and talk with them. Sometimes it takes knowing the right questions to ask to get them going, but once they get going…sit down, be quiet and write as fast as you can.

Lessons learned from somebody else’s experience, like Daryl’s,  is a lot less painful than learning it on our own. I really appreciate the people that have shared their words of wisdom with me so that I can improve what I am doing without having to take the hard knocks myself.

I will be sharing a few lessons learned (Dec. 2010) with the Utah ASHRAE Chapter when I give a presentation called “Who Stole My High-Performance Building”.  It will be a fun and informative presentation, and I will share parts of it in the future on this blog.

Todd Rindlisbaker, P.E., QCxP, LEED AP, HBDP, CCP, has been in the HVAC/plumbing design and commissioning business since 1993. He has extensive experience in project management, HVAC design, and energy studies and specializes in hydronic heating and cooling systems, controls optimization for comfort and energy efficiency and in commissioning. He has been involved in the design, installation, and commissioning of mechanical, plumbing, and building management systems throughout the United States and internationally.