Monday, February 14, 2011

Existing Buildings Guide

I recently received an e-mail from the chair of TC 2.1 (Thermal Comfort), advising us of a review on an energy Efficiency guide, prepared by a collaboration of The American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE). It came with this announcement:

Attached, please find information from the EEG-EB-TG Project Monitoring Committee regarding the Peer Review for the 60% Draft of the Energy Efficiency Guide for Existing Commercial Buildings: Technical Implementation.

The information includes the review input form and instructions along with a copy of the 60% Draft document. The document can also be downloaded from the AEDG web page on the ASHRAE web site ( starting Monday, February 14, 2011. The peer review period will be from Friday, February 11, 2011 through Friday, February 25, 2011.

After a quick glance through this guide, this version has yet to make any reference(s) to human comfort and/or Standard 55 (Thermal Comfort). While the guide is geared towards making an existing building more energy efficient, some proposed changes are likely to impact human comfort by incomplete and yet-to-be-developed recommendations under the “Proper (Reduce) Ventilation”, “Air systems distributions”, and “Lighting” sections on pages 41, 46, and 52, respectively.

There is a real potential for the occupant to suffer in the name of energy savings. As I point out in my recent ASHRAE Journal article (December), the cost of occupant salary is on the order of two magnitudes greater than the cost of energy in a building. The savings that can result in measurable energy reduction may be three orders of magnitude less than occupant salaries.

Those of us that remember the EBTR of 1979 (I was chair of 2.1 then) remember that actual energy savings from that ill conceived plan actually resulted in an increase in energy. The report from the DOE that discovered this fact has been successfully buried and was never published.

Non-validated energy model calculations can likely prove whatever the researcher wants to prove, especially where part load calculations come into play. It is distressing to learn that there are no references to comfort in the document. In the quest for Net Zero buildings (a term which I understand is being changed, much like “global warming” is now “global climate change”) we are likely to wind up with Net Zero Acceptability.

I strongly suggest that readers who are interested in good air distribution design, occupant comfort, and productivity take the time to read and review these proposed guides. Please note the review period.

Authored by: Dan Int-Hout, Chief Engineer Krueger

Wednesday, February 9, 2011

ASHRAE Winter Meeting Update

Another Winter ASHRAE meeting is behind us. I never made it to the show, as I was fully involved in technical meetings the whole time. Some actions that were taken on the committees I am involved in:

ASHRAE 62.1: Proposed changes will strengthen the requirement that ventilation must be added to VRV and fan coil units in apartments, multiple room dormitories, and multi room hotel spaces. It seems that ventilating a hotel room by sucking air from the corridor under the door by using the toilet exhaust isn’t all that effective.

VAV systems will be required to modulate the outdoor air damper to maintain the minimum ventilation rate at all times. It seems likely that measuring outdoor air quantity will be required in 62.1, as it is already required in 189.1. This should resolve issues some have had with VAV systems that they don’t provide proper ventilation at part load.

ASHRAE Standard 55 (Comfort): We are moving towards a form of mandatory language and better understanding of what is required for compliance. So far, the mandatory language will only be for design, not for current conditions. Mandating clothing and metabolic rate is of course, problematic.

TC 2.6 (Sound and Vibration) - Duct insertion loss being reevaluated for lengths longer than 10ft, in a research project at UNLV, which some of us toured on Tuesday morning. They have a very impressive facility, and are completing a study on inlet effects on diffuser performance.

TC 5.3 (Air Distribution) – Several Handbook chapters are being updated. If you haven’t looked at the ASHRAE Handbook chapters on Air Distribution in the past few years, now would be a good time. Lots of new stuff has been posted there.

TRG7 (Underfloor Design Guide Rewrite Task Group) – We have about 90% of first drafts in hand. Section ‘captains’ will be working towards closure on these drafts over the next few weeks. It is hoped we can have a final draft at the Montreal meeting in June.

As usual, the ASHRAE technical meetings could just as easily be held in a basement in Dubuque, as I seem to spend a lot of time locked in windowless rooms. Las Vegas was a fun place in the evenings, of course. The 6AM breakfast meeting was a challenge on Sunday, though.

It was great to see all the Krueger Reps at the Ghostbar on Sunday night!

Authored by: Dan Int-Hout, Chief Engineer Krueger

Monday, February 7, 2011

An Engineering Showcase

I was visiting an Engineer’s office in Scottsdale to do a lunch and learn. They had just moved into a new space, designed by them. So new, in fact, that one of the conference rooms had yet to have the table installed. But what impressed me was the use of innovative technologies in the air distribution. Cases in point:

1) Conference room 1 utilized a set of variable flow linear grilles discharging against the inside (glass) wall, with returns located above the windows. This would “roll the room” and in fact, could be considered displacement ventilation, as the air enters the occupied zone at the floor, horizontally (the occupied zone is defined as starting 2ft from any wall).

2) Conference room 2 utilized 4 displacement diffusers located on the interior wall (not glass!) between the doors at each end of the room, for cooling, and floor grilles at the perimeter for heating. Again, the returns were above the window.

3) Closed offices, each with a glass wall and sliding glass door, surrounded three sides of the open office which had 4ft sound dividers and a 20 foot high open ceiling. Closed offices had a plaque diffuser in each.

4) There was no ductwork above the open cubicles. The open office area was conditioned by drum louvers located on the wall above the closed offices on three sides, with West facing glass on the 4th side. The drum louvers were adjusted to spread the air across and over the low partitioned offices. The drum louvers nearest the window wall conditioned that space from either side.

All too often I find Engineers’ offices have lousy air distribution systems. This was an exception to the rule, and should provide a showcase for different technologies for their prospective customers.

Authored by: Dan Int-Hout, Chief Engineer Krueger