Overview

Concurrent with a district-wide Capital Improvement Plan initiative, Entech performed a Preliminary Energy-Use Analysis for the Parkland School District. The EPA Energy Star Portfolio Manager was used to determine the benchmark performance of each building and to recommend level 1, 2, or 3 energy audits accordingly.

The Parkland School District is comprised of eight elementary schools, two middle schools, and one high school, totaling approximately 1.5 million square feet. The annual utility expense for these facilities from July 2010 through June 2011, was $2.69 million. This corresponds to an expenditure of $1.81 per square foot annually for utilities, indicating a significant amount of available savings. Of the annual $2.7-2.9 million utility expense, 72% was associated with the two middle schools and the high school, which represent only 58% of the total facility square feet. This high-energy use intensity is reflected by Energy Star scores of 3, 16 and 47. Entech recommended a Level 3 Energy Audit for each of these three buildings to provide a detailed analysis of annual energy, and operating cost and savings associated with potential energy improvements.

Existing energy usage for each facility was recreated using water, HVAC, lighting, and miscellaneous energy usage models. Energy Conservation Measures (ECMs) were evaluated by modifying the existing models to determine the estimated energy savings associated with each ECM. As the audits were completed, economically viable ECMs were incorporated into the Capital Improvement Project.

Solution Details

Parkland High School (478,000 SF):
The existing annual energy consumption from July 2010 through June 2011 was 51,536 mmBtu, at an annual cost of $523,114. We recommended 12 ECM projects with an energy usage reduction of 44% or 22,688 mmBtu. The estimated cost to implement the recommended projects was $719,576, with an associated savings of $342,663 annually. The 12 ECM projects recommended provide a cumulative payback period of 2.1 years.

Orefield Middle School (201,000 SF):
The existing annual energy consumption from July 2010 through June 2011, was estimated to be 26,546 mmBtu, at an annual cost of $660,363. We recommended nine ECM projects with an energy usage reduction of 68%, or 18,041 mmBtu. The estimated cost to implement the recommended projects was $1,869,379, with an associated savings of $432,753 annually. The nine ECM projects recommended provide a cumulative payback period of 4.3 years.

Springhouse Middle School (218,000 SF):
The existing annual energy consumption from July 2010 through June 2011, was estimated to be 12,247 mmBtu, at an annual cost of $270,465. We recommended eight ECM projects with an energy usage reduction of 21% or 2,528 mmBtu. The estimated cost to implement the recommended projects was $677,315, with an associated savings of $73,491 annually. The eight ECM projects recommended provide a cumulative payback period of 9.2 years.

The majority of ECM savings at each of the various buildings was recognized through a combination of some of the following significant factors: the installation of minimum 92% efficient hot water condensing boilers; the installation of high-efficiency air source heat pump unit ventilators; and the implementation of control changes, including time of day scheduling, optimum start/stop, static pressure reset, VAV minimum reduction, CO₂ controls, and ventilation reduction.

Summary:
We employed a strategic approach to identify buildings with the greatest potential for energy and cost savings, while maximizing the client’s investment dollars, both in engineering and design fees. Through our efforts, we were able to assist the client with the implementation of a number of ECMs and complete building renovations, as part of their Capital Improvement Plan project.