Code Classroom
Ron George, CPD President, Plumb-Tech Design & Consulting Services, LLC
M
Green codes and standards: Which ones should you use? floor and the maximum allowable pressure on a lower floor in order to eliminate the use of pressure reducing valves and re-pressurization pumps that waste energy. I also asked whether he would be covering high-rise domestic hot water system circulation. The speaker had a “deer in the headlights” look and said, “This is how the developers and contractors I work with want to do it, because it’s cheaper. If I don’t do it their way, they will go to someone else.” Establishing pressure zones would eliminate pressure reducing valves, which are a maintenance nightmare, on all the lower floors. The energy savings from eliminating these valves, which I refer to as “energy wasting valves,” pays for itself in a few short years. Having one booster pump at the base of a fifty-story building, using pressure reducing valves on all the lower floors, is like driving your car down the street with your foot firmly pressing the gas pedal all the way to the floor and controlling your speed with the brake pedal. The pump is like the engine; lots of fuel will be used if the accelerator is on the floor. The pressure reducing valves are like the brakes, which will wear out fast and often if the car engine is always racing at full speed. When the brakes wear out, the speed increases or, in this case, when the pressure reducing valve wears on the seat there will be increases in pressure well above the code-allowed 80 pounds per square inch. A single pressure booster system wastes an enormous
any new building projects are being advertised in the various trade publications as being sus- tainable, as receiving an award for meeting the
requirements for an environmentally friendly building or for being green. Being “green” means different things to different people. Kermit the frog is green in a different way, although he probably lives a pretty green lifestyle. Our ancestors and the American Indians could be classi- fied as green. They lived in log cabins and teepees, and they used only the rainwater they collected and whatever resources they needed to survive. They had a very small carbon footprint. Looking at pictures of the buildings that are receiving
awards, I notice that they often have a lot of large, open spaces, with almost all glass on the exterior walls and, many times, with curved exterior walls. The articles always explain that, because of the amount of glass on the exterior, these buildings save money on lighting costs. I wonder whether the calculated amount of energy saved on lighting is more than surpassed by the addition- al heating and cooling loads that would be required for a building with properly insulated walls and normal sized windows. I have worked on many buildings with curved walls
and corridors. It seems that in almost every one of them there is lots of wasted and unusable building space that must be heated and maintained over the life of the build- ing. There are also additional costs associated with the unusual design features; odd angled corners in rooms leave lots of wasted space that doesn’t seem to work out for furnishings or the building’s piping, ductwork and equipment layout. It seems that a significant portion the square footage of these so-called “green” buildings is wasted with inefficient floor plan designs. The object of the award points systems is to encourage
energy efficient designs for buildings that will cost less to build and operate. Builders get points for using local materials and energy efficient equipment. One project I worked on utilized a central chilled-water distribution system for a housing project, just because the builder would get points for using a chilled-water system. No chilled water, no points. In that case, the points system was driving the design. I sometimes scratch my head and wonder how builders came up with the designs, and I wonder about the points system that allows a few of the higher award winners to be such obviously inefficient designs. I remember attending a seminar on high-rise plumbing
design. The speaker was explaining how he had designed a recent high-rise building. I asked whether he would be covering such issues as booster pump selections, the maximum allowable pressure zones in a high-rise build- ing based on the minimum desirable pressure on the top
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amount of energy. A more efficient design is to install a pressure booster for each pressure zone, which would be four or five stories, depending on the floor-to-floor height and the available street pressure. A four or five zone system can reduce the horsepower consumption by about 75 percent with triplex or quadraplex booster pump packages. Multiplexing pumps significantly reduces the horsepower of the pumps needed to meet demand. Adding additional pumps to each booster pump system allows smaller pumps. The speaker said, “Cost was the driving factor. The developer does not care about energy or operating costs.” The building design was not addressing energy savings and the additional building maintenance costs for the life cycle of the building; it was only covering first cost for the developer, so that he can get it built cheap, sell it and move on and let the buyer and tenants deal with the poor design that will lead to excessive energy use, poor per- formance and high maintenance costs. Most points systems for energy efficient buildings do
not cover many of these high-rise plumbing design issues. I have seen terribly inefficient high-rise building designs marketed as green and environmentally friendly. It seems like it’s all talk or marketing hype and no action. Whether it’s part of a green or environmentally friendly
Continued on page 22 October 2011
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