Existing building thermal performance assessment methodology?

3 posts / 0 new
Last post

G'day,

Can anyone suggest other then a software program a 'methodology' for the assessment of the thermal performance of existing commercial buildings?

Determining the occupants thermal comfort levels and the air indoor quality would be beneficial but not essential for the methodology.

Thanks in advance.

Regards,
Richard

ecodesigns know the elements work with them

Richard M Sapwell's picture
Joined: 2011-10-02
Reputation: 0

Richard,

The most current publication that covers all aspects of how to rate a building's performance would be the ASHRAE Performance Metric Protocols or PMP. The PMP has three levels of evaluating the energy, water, IEQ (thermal comfort and IAQ), acoustics and lighting performance. In the PMP special emphasis was given to references for both North American and European Standards where the reader could go to learn more.

Unfortunately, assessing the thermal performance of a real building is a bit more difficult because of the compounding errors that occur when one tries to unravel the performance of the various heat transfer pathways, (i.e., the windows, walls, roof, occupants, infiltration, internal loads, etc. Furthermore, to make matters worse, the smaller the building (i.e., residential), the worse it is to decompose the thermal components, i.e., the window SHGC from the U-value, or the infiltration.

There have been some worthy attempts that have shown certain things can be coaxed out of the data. The earliest one that I'm aware of was the PSTAR by Kris Subbarao in the early 80s. This was later picked up by folks at SERI, now NREL and carried into newer analysis, for example, the recent work with BESTEST EX by Judkoff and Neymark for residential. There was also the mid 90s work by Manke and Hittle that demonstrated the use of empirical parameters, sometimes that were physically unreasonable but gave the best fit. There was also a bit of work done by Palmiter on black and gray box methods, and the "test-hut" work published by Yaeger in the late 1980s. Other works include Mazzucchi, and Kaplan, and of course the work by Hsieh et al. at Princeton. You can pick up the thread on these by reading the literature searches in one or more of the thesis on our web site by Bronson, Bou Saada, Abbas, Song, Kim and others on calibrated simulation.

Hope this helps.

Jeff S. Haberl, Ph.D.,P.E., FASHRAE

Jeff Haberl2's picture
Offline
Joined: 2011-10-02
Reputation: 0

Thanks Jeff for the great references for this 'overview' information. I thought you (or someone) might also be able to point to some overview reading regarding schematic energy analysis tools and M&V as a service.

I'm assuming that the mid-sized firm where I work is not unique regarding our challenge to learn more about actual building performance (signed the 2030 carbon challenge). We consult with engineers and in house focus primarily on architecture and landscape. So we use tools like Vasari, Revit, and Green Building Studio to approximate EUI at a massing level, then hand off the energy analysis to the pros (our engineers tend to use HAP or Trace). Our goal with these tools is to understand the relative energy performance of different massing and fenestration designs. While they are nice and simple for us architects, they don't seem to produce detailed reports that we can share with our engineers to accomplish a sense of confidence in the model. However, we are also concerned that learning more sophisticated software (IES, Ecotect, EnergyPlus, eQuest) might not actually improve our design. My question is if there is a relatively recent summary of energy analysis tools available and how they relate to schematic design? Bigger picture, what really needs to occur in the AEC industry to execute competent energy design?

The second question is similar, but regarding M&V. We have seen how third-party commissioning can have a huge impact on performance. We have also started to collect utility information from some of our clients with the intent to better understand actual performance. While we specify numerous meters to track energy consumption, we have not actually had a client follow through with M&V at the level of IPMVP (due to the cost of this service). So we are struggling to gain experience with calibrated energy models and what they can tell us about our initial design assumptions. Is M&V a service that really helps someone operating a 30,000 sf building, or is it more a way to close the loop on design in the hope of doing better next time? Is there a summary of the rationale for M&V, and best practices for delivering this service?

I appreciate that these are pretty broad questions - any reading suggestions are greatly appreciated.

Stuart Shell, AIA, CDT
LEED AP BD+C

Stuart Shell's picture
Offline
Joined: 2011-10-02
Reputation: 0