Off the Shelf
Many building features contribute to exceptional energy efficiency. The building exceeds the requirements of ASHRAE/IES Standard 90.1-1989 "Energy Efficient Design of New Buildings Except New Low-Rise Residential Buildings".
The building has relatively long north and south walls, with shorter east and west walls. This creates energy efficiency due to the fact that the winter sun will penetrate the south wall throughout the day. The summer sun is higher in the sky, which creates more reflection of the midday sun's heat off of the south facing surfaces. The late afternoon and evening sun will broadcast onto the shorter surfaces.
The building's atrium glass has a low-emissivity to allow visible light to enter while reflecting larger percentages of infrared light. The windows throughout the building, also low-e rated, are inset and shaded by the building walls and light shelves. These shelves reflect light upward across ceilings, thereby projecting the light to interior spaces which increase their attractiveness and creates more comfort. The canopy and trees shade the west entrance of the building.
The atrium design allows most of the office space in the building to receive natural light. The natural lighting effect is enhanced using light shelves.
Open office areas use indirect lighting with task lights. The general lighting level is ±25 footcandle at the desk surface, rather than 50 footcandle typically used in most office buildings. Because illumination is a squared relationship, 0.52, or only 25% of the general light is required, and only 25% of the heat needs to be removed by the cooling system.
All occupied spaces utilize motion sensors to detect occupants for the control of the general lighting. There is one sensor per 1000 square feet. The general lighting uses a more energy efficient T-8 fluorescent bulb with electronic ballast.
Some incandescent lighting is used to highlight conference and training room walls because it is more aesthetically pleasing and the light dimming control will be more precise. In order to conserve energy, the building's exterior lighting is on timers.
A state-of-the-art building automation system offers computerized monitoring of the energy related information throughout the building and controls equipment accordingly.
A chilled water system and central air handling system, located in an equipment room immediately underneath the domed roof, provides cooling for the building. Two large rotary screw chillers, 231 kilowatts each, use environmentally friendly refrigerant (HFC-134a). A constant volume primary chilled water loop feeds variable frequency drive secondary pumps, and these provide water to the coils in the four large air handling units (AHUs) serving all five floors of the building.
The four AHUs have variable frequency drive fans with 200,000 cubic feet per minute (94,400 liters/sec) total capacity. The supply air system has variable air volume (VAV) boxes with a maximum 2000 sqare feet of building area served per box. Cool air is provided at 55 F to 65 F as determined by the building automation computer to supply effective cooling for all spaces and to minimize energy consumption.
The perimeter boxes have fans that can either draw from the supply air ductwork, or the ceiling plenum, and push air through electric heating coils that have a minimum of two stages of heat. The large conference rooms and training rooms have two boxes and dual setting thermostats that stage the boxes on a one-at-a-time basis. Approximately eight separate exhaust systems provide normal exhaust for the large conference rooms. Toilet rooms have separate exhaust as required by code. Garage levels one and two are ventilated with 6 air changes per hour in order to remove the accumulation of any dangerous combustion products. Sensors provide input to the building's automated computer system so that safe operation is monitored. The atrium's smoke evacuation system requires 280,000 cfm be exhausted. The return air fans provide two-thirds of the smoke evacuation and dedicated smoke evacuation fans accomplish the remaining one-third. Balcony doors open automatically to facilitate make-up air.
|ELECTRIC VS. GAS
The building was initially intended to be heated with natural gas. During building design, Koll Development Company teamed-up with the Board of Public Utilities, Kansas City, Kansas, and structured an Economic Development Rate Rider for this building. This rider offers a 5-year, stair-stepped discount on the cost of electric service and its application will result in an estimated energy and maintenance cost savings of $1,200,000 during the 10-year EPA lease. Electric utility companies across the nation are being urged to use low sulfur coal and to use environmentally friendly technologies to generate green power. The Federal Government is leading our nation in buying green power where it is commercially available.
WATER CONSERVATION / QUALITY
Low flow faucets reduce the amount of water used, and that reduces the energy required to heat hot water.
The EPA Green Rider for the Kansas City Regional office required, "water conservation, through low flow shower heads and toilet room fixtures, landscaping with native species and drip irrigation systems."