AEC TECH NEWS #15319 Oct, 2005
AEC Technology in the NewsAIA looks at post-Katrina construction;
NIST reports on airtight building design;
and DOE upgrades EnergyPlus
Institute of Architects has released a report on the effects of Hurricane
Katrina on the U.S. Gulf Coast region and the projected aftermath and longer-term
outlook. The report, "Economic and Construction Outlook in the Gulf States After
Hurricane Katrina," was prepared by Economy.com, an economics consulting
firm that specializes in forecasting regional growth patterns. It pulls heavily
from data compiled by Economy.com and from surveys of AIA members regarding
the timeline of rebuilding following past natural disasters.
Total damages of Hurricane Katrina are estimated at $150 billion to $200 billion, according to the report -- truly a staggering amount of money. Not addressed in the report is the equally staggering human toll, in terms of lives lost and those permanently disrupted. This event has been described as the single most costly natural disaster ever in U.S. history, and its effects will be felt for many years into the future.
The AIA report concentrates on residential housing stock in the region. Accurate estimates of losses to nonresidential buildings and public infrastructure are not available, but are expected to be considerable. Loss of housing stock in the region is estimated at 275,000-300,000 homes, some of them perhaps lost permanently. Equal numbers of homes are not necessarily lost but are in need of major repair.
The report breaks down projected economic impacts and population fluctuations in 2006 and 2008 by three states -- Louisiana, Mississippi and Alabama -- and assesses the potential short-term impacts on building materials and labor availability in the region. Building materials costs are expected to rise and likely result in short-term shortages of certain materials. Labor needs are likely to rise, but this coincides with a projected national downturn in residential construction, so labor needs in the Gulf Region are likely to be met by an influx of people seeking opportunities there. Except for a projected shortage of some specialized engineering disciplines, the report is not specific about the availability of building design professionals in the region -- which is somewhat surprising in a report commissioned by AIA. The full report is available using the link above.
NIST Studies Energy Impact of Building Envelopes
Another interesting report was released recently by NIST (National Institute of Standards and Technology), titled "Investigation of the Impact of Commercial Building Envelope Airtightness on HVAC Energy Use." It states that increasing the air-tightness of building envelope construction could result in significant improvements in energy use nationwide. This conclusion seems fairly intuitive and obvious: Reducing air infiltration in typical buildings should reduce the need for heating and cooling. But I found it somewhat ironic, as well.
At a time when architects and engineers have been roundly criticized for designing air-tight buildings without operable windows, this report suggests this could be exactly the right approach. Operable windows have been anathema to HVAC engineers for many years because it's difficult to quantify what humans are likely to do if given control of air infiltration. If a critical factor such as outdoor air intake is not under the designer's control, it's challenging to design for optimum economic system efficiency.
On the other hand, operable windows in some buildings could provide occasional, adequate control of the indoor temperature of many buildings, without additional energy use. Even so, solar radiation can heat one part of a building enough to require cooling, while another part in the shade requires indoor heating. What's the poor HVAC engineer to do? Assume that the human occupants will exert the proper control of the system as designed? That could result in some interesting lawsuits.
AEC technology today can analyze building design and address this specific problem. BIM (building information modeling) should eventually be able to analyze the variable factors on a more detailed, space-by-space basis and point toward the most economical system for a specific building in a specific climate. It should greatly enable finding the most economical and energy-efficient solution at an early stage in the design cycle. It's not there yet, but it's coming.
DOE (U.S. Department of Energy) recently released version 1.2.3 of the free EnergyPlus software for building energy analysis. EnergyPlus has been in development at DOE for many years -- in previous incarnations under names such as BLAST and DOE-2 -- and it has been used as the computational foundation underlying many engineering energy-analysis programs. However, it has remained off the radar screen for most architects and building designers because for most of them, EnergyPlus is of little use by itself. DOE has not developed a user interface that makes EnergyPlus very usable to anyone except a computer software engineer who can provide the necessary input format and make the output easily understood and usable.
But third-party developers have been creating user interfaces separately, and several examples are available for different purposes. Perhaps some enterprising organization is even now developing an aecXML input interface, and a direct link to a BIM model, to enable building designers to use the results in responding to the information in the NIST report about building energy use.
Download a free copy and check it out for yourself.
ABOUT THE AUTHOR
Michael L. Dakan, AIA, is an architect, author and independent AEC technology consultant. E-mail him at email@example.com.
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