Monday, May 23, 2011

Mid-Year Predictions Follow-up

In the interest of full accountability, I have provided an update to my January top 10 predictions, as we are half way through the year.

1. LEED 2012 will be approved, pretty much as it is in its first public review.
Update: Second public review due out in a couple of weeks. Nothing major proposed different - ventilation will likely be a restaurant menu – 1 from column A….

2. The ASA Classroom acoustics recommendation (essentially NC=26, ANSI 12.60 ) will become a requirement in many local codes and may be a part of the next IBC. It will also be a requirement of the ADA governing bodies, forcing a redesign of many school HVAC systems
On track. Good news is that AHRI 885 is designated as a primary method of estimating sound levels in schools and other places as well.

3. Over my objections, the ASHRAE Thermal Comfort Standard (55-2010) will be rewritten into code language. I predict this will result in gross misuse and misinterpretation of the requirements and will make lots of money for trial lawyers. (I hope I’m wrong on this one.)
A sub committee has been formed to implement this proposed change. I volunteered to be on it.

4. With any luck, we will get a rewritten ASHRAE UFAD Design Guide out of committee at the summer meeting. The current manual has been pulled from the ASHRAE bookstore following complaints, most noticeably from the GSA, over lack of discussion of the potential negative issues with this design concept.
Final first draft has been assembled and we will review it at the Montreal meeting. Really good news is that I will move to Vice Chair after the June meeting.

5. Displacement Ventilation will see significant use in classrooms (it’s quiet, see item #2 above).
This trend continues.

6. Chilled Beams will continue to be the “darling” of innovative engineers. We will not see validation of the calculated energy savings from this relatively new technology. That will not, however, prevent estimates of significant energy savings, resulting in LEED points.
Still no peer reviewed data on energy savings with this technology. Developing AHRI and ASHRAE test methods should put to rest some unfounded performance claims.

7. For the umpteenth year in a row, BOMA will state that the number 1 reason for not renewing the lease in high rise buildings is “occupant dissatisfaction with the building environment” (ie: comfort). See item #3 above.
Still waiting for the 2010 data from BOMA.

8. The market for HVAC components will continue to be relatively flat with local ups and downs.
It's looking better in some places, still flat in others. Fortunately, no major downturns seen, but pricing pressure is pretty grim everywhere.

9. VAV overhead air distribution will continue to be (by far) the most used system in new buildings.
Unchanged. While some other systems are seen in some specifications, most continue with the tried and true overhead VAV designs.

10. The Cowboys will continue to disappoint their fans.
I can’t even predict if there will be a season this year.

Authored by: Dan Int-Hout, Chief Engineer Krueger

Tuesday, May 17, 2011

Observations of a Canadian LEED Certified Building

While I was in Canada a couple weeks ago, I was given a tour of an almost completed Quebec Government building. The building was an extension of a combined train station / administrative office complex. The addition was the equivalent of the Department of Transportation in the US (I have no idea how to translate that into French).

Language barriers aside, our tour guide was a manufacturer’s rep who had sold all of the air distribution in the new addition. We even got to meet the lead design engineer, as the building was going through the commissioning process, and he was overseeing that process. I was impressed with several things in the new building:

1) The addition was a very fast track construction project, completed in what may be record time, with 6 floors of offices and a parking garage. People were working in the building before it had been commissioned!

2) The open plan office had no closed offices at the perimeter, all conference rooms and executive offices were located in the core, resulting in excellent visibility.

3) There were no desks against the windows, and the spaces near the windows were all corridors.
Partitions were low height, except for some separating operational areas, and these 6ft partitions were all perpendicular to the window wall, allowing excellent daylighting into the interior.

4) The south facing wall had exterior shading and an interior light shelf (with a gap to allow airflow down the windows), again to increase daylighting into the interior.

5) The HVAC system was ECM powered fan coils with VAV boxes controlling ventilation air into the fan coils. The lead engineer said the result was less than 1Watt/SF load, and there were no true air handlers, only DOAS units bringing in and conditioning outside air.

6) The zone air distribution was European style fully adjustable radial pattern 2x2 fixtures with 2’cube plenum boxes on top. These constant volume air devices have very high induction and resultant short throws, and appear to minimize jet collision and resultant downdrafts. Air flow rates were relatively low, less than 1cfm/sf in interior zones.

There were also some issues:

1) It was also reported that the combination of ECM motors and digital lighting ballasts resulted in a building power factor of 0.85! As there is a power station in the basement, power was re-conditioned on site.

2) The air outlets have relatively high pressure drop (0.5”) and are at least 5x the cost of typical office diffusers in the US. This cost is typical in Europe, but would be considered prohibitive in most US designs. There is little data on the performance of this style of diffuser in terms that are comparable to US designs; nevertheless, we will be testing a unit to get comparable performance data.

Authored by: Dan Int-Hout, Chief Engineer Krueger

Monday, May 9, 2011

Comfort & Energy Savings

I was asked to post some thoughts to my fellow presenters at the upcoming Greenbuild, in October, in Toronto, on my part where we are doing a "yes, you can have comfort and energy savings" talk. Here is what I sent them:

I've been stuck in rainy Quebec province, with limited internet access, and time, but I've been noodling the subject of the somewhat diluted 30% proposed ventilation credit (for LEED 2012)and the "same degree of ludicriness as bicycle racks" comment we got from one of the energy mavens.

I won't try to come in on naturally ventilated buildings as I suspect they represent about 1% of available spaces.

I am of course concerned about the low comfort scores LEED buildings are getting, as its hard to argue for the availability of comfort options if we can't seem to be able to achieve it anyway.

I fear that part of the problem has been the emphasis on energy at the expense, or just plain ignorance of, comfort requirements. Nonetheless, I believe there are innovative options available to both improve energy efficiency and achieve a level of comfort. I am concerned that the calculations of energy savings are greatly overplayed, and never surprised when they aren't realized.

The reality is that when folks are not comfortable they don't just "make do". They bring in heaters, and sometimes fans, to increase their comfort level. Both are huge energy wasters, as the energy they use generates heat which then goes to the chiller, costing twice the energy used by the stopgap measure.

All that aside, I'd like to focus on the potential for innovative systems to maximize ventilation when outside conditions permit, minimize it when it doesn't, and ensure that economizer isn't mis-applied (pushing the economizer envelope resulting in high humidity in the space, as was alluded to by C Dorgan in one of our recent phone calls). At the same time, the real issue, I believe, is building operations in part load conditions (which are likely 90% of the time).

System design is not an unknown science. We know how to design for effective part load operation, but seem to get lost in design load strategies. Energy costs about $2/sfy in most climates (likely less in California). Saving half the energy (probably unlikely) has a really long payback in a building that costs $10/sf extra to build. At $30/sf, the payback is 60 years. Yet building owners continue to sign up for silly stuff. I suggest we get real, and discuss opportunities to design buildings without added first cost that actually work.

Radical, huh?

Authored by: Dan Int-Hout, Chief Engineer Krueger