Energy Vanguard Blog

Don't Do HVAC to Me

Posted by Allison Bailes on Thu, Aug 2, 2012

building science summer camp 2012 henry gifford psychrometric chartOne talk at the 2012 Building Science Summer Camp stood out above all the others. The last speaker on Tuesday was Henry Gifford. (Yes, that Henry Gifford!) When he was done, the majority of the audience stood and applauded. The next morning, camp counselor Joe Lstiburek told us there have been four standing ovations at Summer Camp. Henry Gifford has gotten two of them.

His talk this year wasn't about the US Green Building Council (USGBC), their LEED program, or his lawsuit against them, although someone did ask about it during the Q&A. He did start with a list of acronyms and definitions, though, which included the new designation, LEED PP, for LEED Plaque Peddler.

No, he spoke mainly about the need for radical simplicity in the world of HVAC. He showed and discussed many problems in the world of HVAC and some of the ways he solves problems for his clients in New York City.

A little background: Henry didn't come into the world of heating, ventilating, and air conditioning system design the normal way. He began as an owner of apartment buildings. A common feature of NYC buildings in winter is open windows because of overheating rooms. That bothered him, especially as a building owner.

It bothered him enough that he started solving problems so that the people in the buildings didn't have to open the windows on those cold days. Now he's one of the most highly regarded mechanical systems designers and installers in the country. In fact, I had lunch a few weeks ago with a retired engineer who wrote a book on psychrometrics, and he said he'd probably lose a debate on thermodynamics with Henry. That's high praise! (Speaking of psychrometrics, did you notice Henry's T-shirt in the photo above?)

In his talk, he spent a while discussing thermostats. "If you don't have a thermostat in every room, you're not even in the ballgame," he said about large buildings with boilers and hydronic distribution. But that's not enough because he showed plenty of examples of thermostats set up to fail: sensors installed near heat sources, set up incorrectly, outdoor sensors in the sun, and on and on.

He attributes the problem to a lack of design. No one shows on the plans where the thermostats go, so the people with the least training and pay make decisions that don't turn out well. He wasn't blaming them, though. "People stoop to the level of the expectations that society puts on them," he said. There's no expectation of how to do this properly, no guidance, and evidently most people just accept the poor results without question.

Radical simplicity. Noticing the obvious is hard to do, you know. But it makes improvement easy. That's Henry's game in New York.

He ended his session with a call for separating heating, ventilating, and air conditioning systems. He claims that when we combine these three separate functions, we introduce all kinds of problems. For cooling, he discussed ductless mini-splits and radiant cooling ceiling tiles. To be clear, Henry focuses on apartment, commercial, and institutuional buildings, not single-family homes.

This is the first conference I've ever been to where a speaker led the audience in a cheer. Near the end, Henry took us through the cheer in the slide below to hammer home his point. (Note: You have to read the words in a heavy New York accent to get the full effect.)

building science summer camp 2012 hvac cheer henry gifford

I do think separating ventilation from heating and cooling is a good idea, but here in the Southeast, if you're installing a duct system for forced-air distribution, it makes sense to use it for both heating and cooling. Of course, the type of building you're looking at makes a big difference, and some things that work in larger buildings like the ones Gifford spoke about won't work in single-family homes. Or they might work but not be cost effective.

What do you think? This is a big, important discussion. Yes, he was talking mainly about larger buildings, but it's good to take a step back and look at what's the best way to do things in different climate zones, different sizes and types of buildings, new versus existing homes, and different types of enclosures.


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Tags: HVAC, ventilation