Tuesday, July 3, 2012

ASHRAE San Antonio Summer Meeting

Another ASHRAE meeting is now behind us. It was in San Antonio, TX which would have been brutal in June, except that the hotel / convention center are located on the river walk, so it was actually pleasant, even in the heat of the day.

I attended a number of Technical meetings; here is a summary of issues covered and developing:

-- Standard 62.1 has been considering the issue of a minimum humidity limit. Standard 55 (Comfort) eliminated the lower limit in 2004, as there simply wasn’t enough compelling evidence to support a lower limit for comfort. Standard 62.1 is finally coming to the same conclusion on air quality data. Manufacturers of humidifiers, of course, are disappointed. There may well be data to support the need for humidification for health reasons, but the data is not very ‘robust’, and is mostly anecdotal.

-- Standard 55’s issue with a limit of 40 fpm for proper use of both the graphical and PMV methods was discussed. I accepted the assignment to provide alternate wording to the section to indicate the correct use of a 40 fpm value. It is acknowledged that any space, no matter the method of comfort control, or even passive conditions, is sure to exceed 40 fpm at some location, due to convection from local heat sources.

-- The ASHRAE Standard 130 (VAV Box Method of Test) acoustical requirement for pure tone qualification of the reverb room doesn’t make sense if the measurement requires only broadband measurements. A member will look for wording in line with current, existing standards to see if they can come up with a more logical requirement. Much of the existing VAV box data was collected in broadband qualified facilities. The wording then may be applied to Standards 70 and possibly others which have a similar issue.

-- End Reflection data was discussed again. There is an ASHRAE Journal statement from AHRI on the subject in the latest issue. We will post it our site soon. I also covered the issue in previous Blogs.

-- The ASHRAE research project 1515 has been reported to be nearly complete. The significant finding from this research conducted at Yahoo’s facility in California is how low loads are in today’s modern buildings, below 6 BTUH/SF for long portions of the day. Most interior zones are designed with about 22 BTUH/SF as a default interior load. The measured load is close to the minimum ventilation and latent control requirement, indicating that systems that manage outside air most efficiently are likely to be the most efficient and that complicated/expensive systems controlling sensible loads are likely not being used in most interior spaces.

-- I have rejoined the Technical Activities Committee (TAC), this time responsible for managing the new Multi-disciplinary Task Groups (MTG’s). These are composed of representatives from different TC’s who are coordinating cross-committee issues, meeting only by conference calls, much like the USGBC committee I have been involved with for the past 18 months. There is some very interesting work taking place here. I reported earlier that when the Handbook Committee of TC 5.3 (Air Distribution) met with the Standard 55 Committee (Comfort) in Chicago, members had to be introduced, as they hadn’t met before. I suspect there are a lot of other opportunities for interplay between committees.

The next meeting is here in Dallas, next January.

Authored by: Dan Int-Hout, Chief Engineer Krueger