An Example of a Sustainable Light Commercial Building
An Example of a Sustainable Light Commercial Building
By Bill Lydon - Editor
It makes business sense.
There can be some great lessons learned from professionals when they put their skills and knowledge to work. I saw this when visiting a 34,100 square feet light commercial building where technology and knowhow were applied to create an efficient, sustainable, and productive environment. The building is a notable exception when contrasted with the typical light commercial building built for lowest first cost resulting in high energy cost, extra maintenance, and an uncomfortable environment.
Environmental Systems Inc. (ESI), a system integrator located in Brookfield, Wisconsin, needed more space and made the decision to be in a sustainable building and utilizing the technologies they apply in a wide range of buildings. ESI was established in 1986 and provides solutions for control & automation, systems integration, security, life safety, energy services and building operations.
Paul Oswald, president of ESI, took the initiative and worked with Hunzinger Construction Company and Stephen Perry Smith Architects in a collaborative design build process to construct a new office space known as Gateway West Sustainable I. Goals for the facility include achieving a LEED rating - the building is currently tracking the LEED Platinum level.
Design decisions were made based on a number of criteria, but chief among these, was that every design decision had to provide a positive, bottom line impact on the business. Some design decisions were not the lowest initial cost, but provided cost savings to the business over their life cycle, and therefore were justified in the final cost of the building.
The results are impressive. The building operates 36 percent more efficiently than current building codes require. ESI occupies 10,000 more square feet than in their previous location, yet the utility costs in the new building are 30% less.
The building is designed with no roof obstructions enabling installation of a photovoltaic (PV) array. This spring an 18 kilowatt PV array is planned for installation producing 8 percent of the overall energy requirements, which can be expanded at a later date. Overall energy efficiency will improve to 44 percent better than code with this addition.
The facility uses an open office design that takes advantage of natural light from windows. Light pipes are used in the interior. The system utilizes Tridium Vykon JACE Controllers with integrated I/O outputting 0 to 10 V to modulate dimmable lighting ballasts to maintain 20 foot candles of ambient lighting based on light sensors. Fluorescent task lighting is used for desk and workstation areas. Building occupancy from the access control system is used as part of the lighting control strategy. If any employee enters the building in off hours their task and egress lighting are enabled. The pen office design allows easy adaptation of next generation lighting technologies when available and practical.
Open office space features efficient lighting and noise masking
Mechanical system capacity requirements were reduced due to the high performance building envelope design. This resulted in a reduction of over 330,000 btu/hr of heating and 14 tons of cooling which would have been required in a conventional design. Heating is provided by a 750 MBH, 88% efficient hot water boiler utilizing hydronic baseboard heating and VAV boxes with reheat coils.
Air Handling Unit
The system also features a 5,000 cfm energy recovery unit. The HVAC equipment is located in the building to provide easy access for maintenance and keep the roof clear for solar arrays. The decision to use an air handling system as opposed to the more common practice of using roof top units is an example of a design decision with a higher first cost, but provides a 106% ROI over the life cycle of the equipment. Based on my experience this should also extend the effective life of the HVAC equipment.
Air distribution utilizes VAV boxes with hot water reheat
The system monitors to ASHRAE 55 Thermal Comfort Standard (www.ashrae.org), calculating the comfort index based on temperature, humidity, and CO2. Roland Gutknecht, ESI Director of Operations, told me the index has always been above 90%.
Systems in light commercial buildings are usually forgotten unless people complain about the temperature being overly hot or cold. In the meantime, energy is wasted before the complaints. This building’s systems are continuously monitored and if equipment is drifting out of proper operating parameters there is an alarm. Problems that can waste energy are indentified early so corrective action can be taken. The alerts are linked to their maintenance management system via BACnet to generate work order.
Vykon JACE Controllers with Integrated I/O Modules
In addition to access control, the building incorporates eighteen cameras inside and outside the facility. Video history is stored for 30 days.
Fire Monitoring & Alarm
The building features fire alarm systems connected via BACnet to the Building Automation System to monitor all initiation and annunciation devices that are part of the fire alarm systems. In addition, the system monitors fire extinguishers for proper pressure and that they are physically in place.
Fire extinguisher pressure status is monitored
The lobby features a large flat screen monitor displaying real-time information about buildings performance.
A number of parameters are monitored and calculated; including energy metering, energy analysis, sub-metering, HVAC, lighting and plug load. Information on the lobby display includes:
- Year to Date savings over conventional design energy model.
- Year to Date savings of Gateway’s actual energy consumption over design model.
- Equivalent tons of CO2 emissions eliminated.
- Equivalent trees planted.
- Equivalent cars removed from the road.
Other design features include minimizing water usage and environmental impact through high efficiency lighting, sustainable landscape design, reducing heat island effect through less paved surface in the parking lot, and implementing the reuse of several construction materials within the overall building design. Noise masking was also done to enhance the fully open office work environment.
The access control system information is used to keep an electronic in/out board up to date.
LEED EB (Existing Building)
ESI has made the commitment to maintain LEED status with an in-house team of 8 people. LEED for Existing Buildings addresses whole-building cleaning and maintenance issues; including chemical use, recycling programs, exterior maintenance programs, and systems upgrades. The LEED for Existing Buildings Rating System is used to measure operations, improvements and maintenance on a consistent scale, with the goal of maximizing operational efficiency while minimizing environmental impacts.
Break the cycle…
The big lesson illustrated here is that you can break the cycle of inefficient design and have a great outcome. There are a number of sectors in the buildings market that have been consistently building to lowest first cost which actually is a bad business decision based on short term economics. Maybe this is starting to change.
Productivity of a working environment has not been used as a return on investment measure in building design even though it is a real economic factor. All of us have likely spent time working in facilities that had bad temperature, lighting and other environmental issues. The National Institute of Building Sciences Whole Building Design Guide suggests that there is a productivity gain to be considered by improving the work environment.
This facility illustrates what can be done with knowledge and, more importantly, a conviction to do things differently. The results are real and make economic sense. Certainly ESI did this building to showcase their skills, knowledge, and knowhow as an experienced systems integrator. They also have a very comfortable and efficient building.