Battling the complexity of designing government facilities: Sustainable buildings/energy efficiency
The government can be a tough customer, and the projects that state, municipal, federal, and military entities approach engineers about are highly complex. Here, engineers with experience tackling such tall orders offer advice regarding sustainable buildings/energy efficiency.
Mohamed Abdelmoneim, PE, Peng, LEED AP BD+C, Senior Electrical Engineer, EYP, Washington, D.C.
Raymond Krick III, PE, LEED AP, Project Manager, RMF Engineering, Baltimore
Allen Poppe, PE, MBA, Principal Mechanical Engineer, Mechanical & Chemical Group, Manager, Stanley Consultants, Muscatine, Iowa
Rick H. Troberman Jr., PE, LEED AP, CBCP, Mechanical Engineer, EEA Consulting Engineers, Austin, Texas Lindsay
Zanders, PE, PMP, Sr. Project Manager/Director of Projects, Primera Engineers Ltd., Chicago
CSE: Energy efficiency and sustainability are often requests from building owners. What net zero energy and/or high-performance systems have you recently specified on government, state, municipal, federal, and military facilities (either an existing building or new construction)?
Zanders: New construction typically has an increased ability to apply power generation and energy efficient design. Applying power generation, such as photovoltaic (PV) cell placement, is limited by existing structures and available space (typically roof). Likewise, energy-efficient design starts with the envelope, and most renovations focus on the interior only. We recently worked with the city of Chicago to build a new public library and a new fire station on a shared block of property. The buildings had opposite HVAC demands (the library was cooling-driven while the fire station was heating-driven), and were able to capitalize on a shared geothermal well field located in a mutual parking lot between the buildings. Land in Chicago is at a premium, so the geothermal well field had vertical piping reaching depths greater than 500 ft. Although the municipality was the common owner, the different agencies needed to find agreement among the shared infrastructure.
Poppe: Our designs have included DOAS, VRF systems, water-source heat pumps, magnetic bearing chillers, and chilled beams.
CSE: Many aspects of sustainability (power, HVAC, etc.) require the building facility team to follow certain practices to be effective. What can an engineer do to help increase the chance of success in this area?
Troberman: We are often the prime consultant to the owner as an MEP engineer. In these circumstances, we have more control over getting the stakeholders together early in design. If you can get buy-in by the facilities group for different systems being specified, there is a higher chance of the systems working the way they were designed. If the engineer is acting as a subconsultant, it is still a good practice to encourage the prime to include the facilities group in the discussions early on.
Krick: Sustainability is not a bolt-on item, so to be successful in this area the entire team must be on board from the beginning of the project. To allow for proper selection of all MEP systems, thorough coordination must occur. I would also recommend doing a full review of the applicable energy-savings codes or standards with each project, as some of the requirements listed in the fine print often get lost in the shuffle.
CSE: What types of renewable or alternative energy systems have you recently specified to provide power for such projects? This may include photovoltaics, wind turbines, etc. Describe the challenges and solutions.
Poppe: UFC 1-200-02 includes a requirement for domestic hot-water solar heating. We have implemented these systems for military facilities in Texas, Hawaii, and Japan. These systems are a good solution for barracks with high service-water heating loads. We have a Department of Energy project under design that includes PV. While these systems are costly, there are significant LEED points available for EA Credit 2 Renewable Energy and EA Credit 1 Optimize Energy Performance.
Zanders: PV systems are more frequently discussed during design. Ignoring the cost of the product, which may be subsidized by various grants or stimulus incentives, the major challenge with applying PV systems in new construction and renovation projects is the open, available space. In urban environments, PV systems are typically located on the roof. Even with highly efficient buildings, the amount of usable area on the roof can house a PV system capable of supplementing only a fraction of the total building energy use. Wind turbines are another renewable energy source we’ve explored. These systems are best applied to wide open areas. The challenges presented when applying wind turbines to government buildings is that they are typically located within cities. Adjacent, inconsistent building size, height and length, and mixes of urban green spaces with nearby developments all disrupt the airflow.
CSE: What types of water reuse or conservation systems have you specified into government, state, municipal, federal, and military facilities? Describe their performance and savings over the course of 1 year.
Troberman: When I worked for the U.S. Army Corps of Engineers, I was project team member on a 1-million-sq-ft hospital project where nonchemical treatment for the condenser water was specified. This allowed the cooling tower blowdown water to be used in the landscape irrigation system. Also, the condensate from the 100% outside-air units was captured and used to supplement the condenser-water make-up system. The annual water savings on this project was calculated to be greater than 5 million gal.
CSE: What are some of the challenges or issues when designing for energy efficiency for government, state, municipal, federal, and military facilities?
Zanders: Energy efficiency is dictated by code. The primary challenge that consultants face to achieve energy efficiency goals beyond code requirements is budget constraints. Designers must keep the budget in mind when making selections-increasing the construction cost is rarely an option, as it requires an appeal to a legislative entity. Government owners do have the 100-year plan in lieu of a 5-year plan, so they are very open to energy efficiency ideas with slightly longer payback periods.
Troberman: Many times, the federal/military projects want tried-and-true systems for energy efficiency, but the latest-and-greatest systems may be better for saving additional energy. This can be challenging when trying to find the best fit.
Poppe: Often, not all of the stakeholders are on board with the energy efficiency requirements. Projects are budgeted as traditional HVAC systems. Even if high-performance HVAC systems are lifecycle cost-effective, the budget may not allow for the upgrade. Many projects are scoped as a traditional HVAC system, such as VAV reheat or using an air-cooled chiller. Often, this is the system that the stakeholder wants and expects. There is resistance when a change to a nontraditional HVAC system is proposed. The water-cooled system may be resisted due to operational and maintenance considerations. When the baseline system in an energy model is a water-cooled system, it is a challenge to meet the baseline system’s energy consumption, let alone exceed it. Some challenges are due to the unique nature of military facilities. We designed a LEED Silver air-traffic control tower. The Green Business Certification Inc. reviewer did not agree with our assessment on the number of floors because some of the floors were very small. Therefore, the baseline HVAC system type changed and the ASHRAE 90.1 Appendix G energy model had to be revised.
CSE: What types of high-performance and/or smart buildings have you recently designed for a government contract? Describe the facility.
Troberman: Many government buildings are now considered "high performance" simply due to the federal energy and sustainability requirements. Projects we have designed include a fire station and the unaccompanied enlisted personnel housing project at the Joint Base San Antonio-Fort Sam Houston.