Download: Adam Joseph Lewis Center - A Paler Shade of Green
Source URL: http://hpac.com/air-conditioning/adam-joseph-lewis-center-paler-shade-green
Sunday, July 6, 2014
Net Zero Energy Buildings
This is a recent article from HPAC Engineering that
describes the history of one of the most famous Zero Energy Buildings (ZEB) in
the country. The Adam Joseph Lewis Center (AJLC) on the campus of Oberlin
College in Oberlin, Ohio was designed in 1998 and put into operation in
2000. This 13,600 ft2 building has been widely publicized as
the first and most significant net zero energy building in the US. The article
describes just how difficult it is to design and operate a low energy building
and moreover how very difficult (I mean approaching impossible) it is to design
a ZEB if the energy production systems remain within the footprint of the
building. It also indicates just how “optimistic” energy use simulations
can be when the designers are charged with reaching an unreachable goal.
As such, it is a commentary on human nature and the desire of many in our
industry to make our work seem better than it really is. As you will
read, the devil is always in the details.
Download: Adam Joseph Lewis Center - A Paler Shade of Green
Source URL: http://hpac.com/air-conditioning/adam-joseph-lewis-center-paler-shade-green
Blog Post Written By: Jerry Williams
jwilliams@8760engineering.com
Blog Post Posted By: Michael Mosbacher
mmosbacher@8760engineering.com
Download: Adam Joseph Lewis Center - A Paler Shade of Green
Source URL: http://hpac.com/air-conditioning/adam-joseph-lewis-center-paler-shade-green
Wednesday, July 2, 2014
Fan Heat and Pump Heat
I originally became interested in fan heat in about 1975. As a young engineer of 27, I found myself assigned to do testing work on an existing high-rise office building in downtown St. Louis. I was attempting to determine why the design discharge air temperature of 55°F could not be achieved on the leaving side of a certain air handling unit. The unit was a high pressure draw-thru unit with roll filters, heating coil, cooling coil, and supply fan serving a two-pipe induction system with induction terminals in the building perimeter offices. While I was making temperature readings to quantify the problem, the chief engineer at the facility saw me working and stated bluntly that he already knew the source of the problem. However, since he had no degree in engineering (or as he put it – no sheepskin), no one would believe him.
Though I was not in the mood for his advice, I had no choice but to listen since at this point, I was a captive audience. The chief engineer proceeded to tell me that the source of the problem was the high pressure drops across the filters and coils. These pressure drops, because of the friction taking place, was causing the air to heat up in transit through these devices, raising the supply air temperature. Though this argument was not correct, I had neither the patience nor the inclination at the time to try to explain why.
As an instructor in the ASHRAE Professional Development Seminar “Air System Design and Retrofit” starting in 1982, many questions arose with regard to the source of fan heat and where in the duct system this heat appears. These questions were asked by competent mechanical engineers, thus indicating the confusion on this issue in our industry. After I grew weary from presenting the same explanation at seminar after seminar, I published the first paper on the topic in the January 1989 issue of Heating Piping and Air Conditioning magazine entitled “Fan Heat: Its Source and Significance”. Now I could simply use it as a handout at each seminar.
The articles to follow were printed again in HPAC Engineering magazine (the new name of the same publication) in August and September of 2005 with the title “Fan Heat and Pump Heat: Sources and Significance”. Pump heat was added here because although the processes seem quite similar, the end results are not. One thing good about articles like this is they are relatively timeless; the physics and thermodynamics of a process simply do not change over time. Enjoy!
Article Author: Jerry Williams
jwilliams@8760engineering.com
Blog Post: Michael Mosbacher
mmosbacher@8760engineering.com
Though I was not in the mood for his advice, I had no choice but to listen since at this point, I was a captive audience. The chief engineer proceeded to tell me that the source of the problem was the high pressure drops across the filters and coils. These pressure drops, because of the friction taking place, was causing the air to heat up in transit through these devices, raising the supply air temperature. Though this argument was not correct, I had neither the patience nor the inclination at the time to try to explain why.
As an instructor in the ASHRAE Professional Development Seminar “Air System Design and Retrofit” starting in 1982, many questions arose with regard to the source of fan heat and where in the duct system this heat appears. These questions were asked by competent mechanical engineers, thus indicating the confusion on this issue in our industry. After I grew weary from presenting the same explanation at seminar after seminar, I published the first paper on the topic in the January 1989 issue of Heating Piping and Air Conditioning magazine entitled “Fan Heat: Its Source and Significance”. Now I could simply use it as a handout at each seminar.
The articles to follow were printed again in HPAC Engineering magazine (the new name of the same publication) in August and September of 2005 with the title “Fan Heat and Pump Heat: Sources and Significance”. Pump heat was added here because although the processes seem quite similar, the end results are not. One thing good about articles like this is they are relatively timeless; the physics and thermodynamics of a process simply do not change over time. Enjoy!
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