Thursday, May 25, 2017

High Performance Air Systems

Almost a year ago I wrote a blog about the new code in Washington State. AMCA objected to the wording of the code through several avenues, and was essentially ignored. As I said then, the code mandates “the use of decentralized ventilation systems using dedicated outdoor air systems (DOAS) to deliver 100 percent outside air independent of heating and cooling systems.” This code, in effect, prohibits central station air handlers.

It seems reasonable to assume that the authors of the code were heavily influenced by proponents of “non-ducted” systems, including VRF, WSHP, and Chilled Beams. All these systems require that outside air be carried through ducts to every space, so “non-ducted” is a pretty poor definition.

AMCA had already formed an ad-hoc committee on “High Performance Air Systems”, issuing a white paper this past January. I presented an HPAS webinar on May 4 (2017) to discuss this white paper and an article in HPAC “Specifications for High-Efficiency VAV Systems,” which outlines the requirements and exceptions to the code. The two documents spell out the advantages of “ducted” systems as well as the disadvantages of the other types. Earlier in 2014, I presented a two part HPAS webinar before the Washington code was in place. Both recorded webinars are available on the Krueger website.

I’m a bit surprised that this isn’t front page news. I am more surprised that after visiting engineers in Phoenix, Rochester, Saskatchewan, and Sacramento, there was no awareness of this code change. I have been predicting that one day we would see a code requiring direct measurement and control of ventilation air into all spaces --- and here it is. As it turns out, the “chilled box” I have been touting for the past few years meets most of the requirements of the identified alternates in the Washington State code. As you might guess, I mentioned this in the webinar!

Wednesday, April 5, 2017

A Look Back

I’ll be doing another ASHRAE talk, this time in in Sacramento, CA. As I prepared for this trip, I started to think back to when I lived there for a year right out of college, going to the USAF Navigator School at the (now closed) Mather Air Force Base, which is about a mile from where I’ll be giving my talk. What I couldn’t believe is that it has been 50 years!

I served 5 years in the USAF, separating in 1972. A year later, I entered the building construction industry, working for Owens Corning Fiberglass (OCF) in their Product Testing Laboratory, in the same Ohio town where I went to college. Within a year, I reopened their Air Lab to study an issue with a specification on room air motion. It was then that I became involved in ASHRAE and the Air Diffusion Council to better understand air distribution, thermal comfort, and applicable standards.

At OCF, for any claim we published or advertised, we were required to have actual supporting test data (conducted in accordance with established test methods). I have carried that “rule” with me ever since, for 44+ years.

At Krueger, we have a set of folders on the server that hold performance data for every VAV terminal unit and air device for all our printed and electronic catalogs, dating back to 1983, when Excel became available on computers running MS-DOS. We learned in the early 80’s that it was not possible to develop an electronic catalog from printed data. Rather, what we found was that the printed data needed to be produced from the same equations and data used to create an electronic catalog. Krueger’s KEC (Krueger Electronic Catalog) was released in 1984 in MS-DOS. It is still able to run, be it painfully, as it doesn’t use a mouse or function keys (neither of which had been invented yet).

As I train new Krueger employees in the art of data gathering, regression, and catalog preparation (printed and electronic), I hope to instill the spirit of traceable and verifiable performance data that I learned all those many years ago.     

Thursday, March 30, 2017

Getting Caught Up

Well, it's March of 2017 and I haven’t posted a blog in 6 months. I guess it’s time.

I last posted a summary of the ASHRAE Journal articles I have had published way back in 2015.

- June 2013 - Slots are Adjustable
- July 2013 - Comfort vs. Energy
- August 2013 - VAV Research Validates Low Airflow Comfort
- September 2013 - Balancing Factors
- October 2013 - You Have to Prove It
- December 2013 - Hospital Operating Room Air Distribution
- January 2014 - Reheat Coil Issues and Answers
- February 2014 - High Bay Air Distribution
- March 2014 - High Performance Air Distribution Systems
- April 2014 - Compliance to Standard 55 (Comfort)
- May 2014 - The Deal about Duct Lining
- August 2014 - The VAV DOAS Fan Powered Terminal
- November 2104 - Proper Selection of Chilled Beams  
- January 2015 - Variable Volume Series Fan Box

Since then, I have had three more published, two in the Journal and the final one in the on-line version of the Journal.

- July 2015 - Basics of Air Distribution - This article provided a basic understanding of how well mixed air distribution works in a space.

- October 2015 - History of Fan Powered VAV Terminal Units - Co-authored with another industry colleague, this article traced the history of the fan powered terminal unit in commercial office systems.

- October 2016 - Part of Making Connections - In this, I described how three technical paths, all starting in the 70’s, progressed to finally come together in 2016 to allow new designs to be employed for improvement in acoustics, energy, and comfort.

Planned for this summer are three ASHRAE Journal papers. They will summarize a significant amount of information gained from a study of series and parallel fan powered terminal units performed by ASHRAE and AHRI. These will be co-authored with other industry colleagues.