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  HCE Designs Advanced Systems For Las Vegas Springs Preserve

Can Las Vegas become a city "of" the desert instead of a city "in" the desert? Can dangerously high water usage and energy consumption be reversed or at least slowed? Can "turf area" be reduced and "native vegetation" successfully substituted? And what will such ambitious transformations cost?†

Answers to these questions and more are the focus of a unique and timely project called the Las Vegas Springs Preserve, which is now in the early design stages. According to Project Mechanical Engineer Kent Bell of Harris Consulting Engineers (HCE), a company with more than 19 years of experience providing heating, ventilation and air conditioning (HVAC), electrical and plumbing solutions in the greater Las Vegas area, this is "a project with many challenges and vast potential."†

"This is a new type of project for Harris and a new type of project for this part of the country. Growing as fast as we are, for the most part, it has been how quick can you build something and how cheap can you build it. Now we have this long-term project to not only save valuable resources, but to educate homeowners and home and commercial builders on green technology. That makes this an interesting and important project for the Las Vegas market at this time."†

HCE is designing the mechanical, plumbing, electrical and passive systems for the Desert Living Center portion of the Las Vegas Springs Preserve (LVSP) Project for Lucchesi, Galati Architects, Inc. The LVSP is owned and operated by the Las Vegas Valley Water District (LVVWD). It is a major link in the delivery system of potable water to much of the greater Las Vegas metropolitan area and is listed on the National Register of Historic Places. One of the goals of the project is to preserve and showcase the historic value of the property.†

"The water district actually has a number of goals," said Bell. "One is to set up a base of operations for the scientists they employ as well as the water conservation staff. Another is to create a headquarters for the desert demonstration gardens being designed to encourage more natural, water-tolerant planting. And, most importantly, they want to demonstrate and promote green building technology and conservation of both energy and water."

According to Bell, Lucchesi, Galati Architects is introducing passive solar heating and cooling technologies into the shell or envelope of the building. So HCE is designing the HVAC as an auxiliary system, including indirect/direct evaporative cooling technology with an auxiliary chilled water backup system. The building is designed to operate in three stages: Passive mode, indirect/direct evaporative cooling, and chilled water mode.†

"Portions of the year, the occupants of the building will have the option of running the building in the totally passive mode. On each end of the buildings will be a cooling tower, a tall column where air is passed through an evaporative cooling medium near the top. As the air cools it becomes denser so it naturally falls and moves into and through the open spaces in the building. At the other end of the building will be a tall solar chimney heated by solar radiation that will draw the air through the building and up into the atmosphere. This will provide a natural cycling ventilation system with minimal use of electrical fans."†

As far as costs go, always a major concern to homeowners and home and commercial builders, Bell thinks the new technologies initially will drive costs up for this project, as compared with more traditional design, but that over time, as with all new technology, costs should come down. By educating people and promoting the idea of conservation it could actually accelerate the use of these new technologies and, correspondingly, increase research, development, and manufacturing by green technology companies. An interpretive planning group is working on the costs/savings aspects of the exhibit in conjunction with the building design team. Also, studies will be done on long-term savings based on the decreased use of energy consumption. This could be the biggest factor in widespread acceptance of green building design in Las Vegas.†

The heating system HCE is designing also features a solar component with a natural gas backup. Approximately fifty percent of the heating load for the building will be directly gained from solar radiation. This concept works well with the desert climate because of the low heat requirement and the high solar radiation levels. This could be a building concept that catches on quickly. HCE is also working with the design team on a plumbing system that emphasizes water conservation.†

"One of the items identified by the design team," said Bell, "was the idea of reusing gray and black water from the building. Basically, the water leaving the building is treated through a solar aquatic wastewater treatment facility utilizing natural enzymes and then an ozone purification to be reused for nonpotable water uses, including the conservation gardens.†

Lighting, another major energy consumer in any building, is also being addressed. Natural lighting, or "daylighting", will be a major component in this design. Supplemental lighting systems will be designed and controlled to use the smallest amount of energy possible.†

"In general," continued Bell, "the building is thermally massive. Most walls are going to be in excess of eighteen inches. What the architects have done is to chop the building up into smaller modules that allow us to get each of the interior areas closer to the exterior of the building. That allows them to build light shelves into the skin of the building that will bounce natural light further into the interiors. The lighting control system will automatically take that into consideration."†

Besides studying green building technology for energy and water conservation, the water district also hopes to get residential consumers to limit the amount of turf area they have. Significant portions of the water Las Vegas uses now goes directly to watering lawns as new residents try to make the desert look like something other than the desert. One of the initiatives is to get people to put in water tolerant landscaping instead of turf and to leave some areas as natural desert. A direct benefit for everyone is that water use reduction will mean power use reduction. Currently, the water district is the power companyís biggest energy user.†

From a public standpoint, the projectís exhibit space will be used to promote conservation of water and energy through interactive displays. Individual homeowners will be able to observe an exploded house that they can walk through and see what green technology is, and what an environmentally friendly house would look like if it had all the pieces and parts. It will include water efficient plumbing fixtures, dual flush plumbing fixtures, environmentally friendly carpets, and other building product materials such as straw bale and rammed earth construction. The idea is that maybe each person walking through can see one or two things that they can do fairly easily and incorporate into their house.†Return to Top of Page

The second aspect is to promote green building technology to the local construction and building design community. Architects and other design professionals can actually see all these technologies incorporated into a "working" building.†

Bell said a lofty goal of the HVAC system -- and the project, as a whole, is to pursue Accreditation from the LEED (Leadership in Energy & Environmental Design) Green Building Rating System. "LEED awards points for different technologies or different areas of an ecologically friendly building. For example, using renewable materials such as the straw bale construction gives opportunity to meeting or achieving the criteria, as does the use of solar radiation for energy reduction. The LEED Accreditation System does not allow the use of any HCFC refrigerants. Only refrigerants with zero ozone depletion potential are acceptable. There are four levels of certification -- certified, silver, gold, and platinum -- depending on how many criteria are addressed.†

"The goal of the design team is to reach a platinum level of certification. To do that it must address green building and energy conservation across the board on all aspects of the construction and design. We are striving to reduce the energy consumption of the building below ASHRAE 90.1 (the industry efficiency standard set by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.) by 50%. The platinum level is a very aggressive goal especially in a climate like Las Vegas. To my knowledge this would be the first platinum accredited building in the State of Nevada."†

Bell was quick to add, though, that this is not just to prove that a project like this can be done once, but is an ongoing effort. "It doesnít do us any good to demonstrate technology thatís already outdated. So, the building is being designed to be easily upgradable. We are trying very hard to limit mechanical aspects of the building that cannot be removed. For example, the photovoltaic panels will be designed to be readily replaced as the technology improves. It really allows the Water District to keep the project current indefinitely."†

Design approval is scheduled for completion by August 2002. The construction of the Desert Living Center from that point is approximately two years. Bell said the design development package is currently being reviewed against the project budget to determine the maximum HCE and the rest of the design team can contribute within the budget. "Itís important for us to get as many of the technologies into the budget to show people what can be done. A lot of work has already gone into this important project, but there are a lot more challenges to come."

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