Learning objective: Designing K-12 schools: Energy efficiency
In K-12 schools, technological advancements, code requirements, and other demands placed on engineers are consistently increasing, while limitations like budget restraints remain a challenge. School districts are demanding energy-efficient, sustainable buildings.
- David Ellis, PE, CEM, LEED AP Senior Vice President of Engineering Allen & Shariff Engineering LLC Columbia, Md.
- Nestor Ortiz Senior Construction Engineer, Project Officer Parsons Brinckerhoff Long Island City, N.Y.
- John C. Palasz, PE, HFDP Mechanical Engineer Primera Engineers Ltd. Chicago
CSE: Energy efficiency and sustainability are often the No. 1 request from building owners during new building design. What is your experience in this area?
Palasz: My experience is that to achieve excellence in energy efficiency and sustainability, the designers need to work with building owners and approach it as a team effort. Prior to building occupancy, new buildings are being fine-tuned to balance system controls and flow rates to provide comfort with the designed operation. Adjusting systems often needs to occur for months and requires adjusting for the heating season as well as the cooling season. I believe that striving for improved efficiency should be an ongoing effort that should not stop once the building is occupied. To do this, it is necessary to have energy meters to establish a baseline and to track the system operation improvements or denigration from year to year. This information is also critical in determining corrective actions for equipment replacement and/or operational adjustments to achieve cost savings.
Ellis: Energy performance and other sustainability practices have been involved in the majority of K-12 projects in the last few years, and going forward are to be a part of all projects based on the implementation of the new codes, in particular the IgCC.
CSE: Many aspects of structure sustainability (power, HVAC, maintenance, etc.) require building personnel to follow certain practices in order to be effective.What, if anything, can you as an engineer do to help increase chances of success in this area?
Ellis: Unique systems that are unique or complex, such as the renewable system types,are often outsourced for their maintenance.
Palasz: My thoughts are that that communication and collaboration between the owner,the commissioning agent, and the design engineer early in the project can greatly improve the chances of success by outlining a process and requiring relevant training and procedures. When the specifications clearly identify the required training, the commissioning agent verifies that the systems are operating as designed, and facility management personnel are trained appropriately, it is very likely that the systems will operate and be maintained to operate as designed. Quite often, after project completion, complex systems are adjusted to simplify the system operation to the level of the building personnel's understanding. Changes in maintenance staff as well asseasonal adjustments may augment the issues and result in systems being temporarilyor permanently bypassed. For these reasons, proper training and systems manuals become critical components to ongoing success.
CSE: Could you please share any experience you have using sustainable heating/cooling tech, such as geothermal systems?
Ellis: VRF systems combine well with a ground-coupled approach for energy performance, which combines energy stored from summer cooling for winter heating,with low energy transport during periods of simultaneous heating and cooling on the same refrigerant run. VRF systems save the energy transfer resistance associated with refrigerant to water and then water to air, as common with four-pipe terminals, and refrigerant terminal delivery of conditioning saves energy compared to all air conditioning delivery, such as with variable air volume (VAV) systems. Solar thermal systems are advantageous for domestic hot water and can be used for supplemental pool water heating.
CSE: Please describe your experience with high-performance building projects in the K-12 arena.
Ellis: While renewable and high-performance systems have been employed, to date we haven't been tasked with delivering a net-zero project, which should be the definition of a high-performance facility.