Finding Balance Between Energy, Infrastructure, and Capital Investment

By Roger Koppenheffer, Principal – Certus Consulting Engineers

In today’s ever-changing world, the balance between energy consumption, building infrastructure, and capital investment could not be more important. As the cost of energy increases and existing buildings age, the cost of maintaining and operating equipment rises. The average life of major equipment such as water-cooled chillers outlined by The American Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) is 25 years. A vast majority of the operating buildings in the DFW area are well beyond this age and many are in need of equipment replacement and upgrades. The replacement of such equipment requires a large capital investment that does not provide any direct revenue to the Owner. Accordingly, many Owners tend to choose first cost over long-term value, attempting to minimize the capital investment needed to replace aging equipment. 

At the same time, the population of the DFW area is growing quickly and consistently year after year. The United States Census Bureau cited the DFW area with the largest numerical growth of metropolitan cities in the United States between 2016 and 2017 with an increase in population of nearly 150,000 in a single year. The state of Texas boasted six of the 10 largest growing counties in the US while the DFW area included four of those counties; Tarrant, Dallas, Denton, and Collin. This consistent growth shows little sign of slowing down. With the increased population growth and associated building construction, the load on the electric utility generation and distribution grid is ever increasing highlighting the need for collaboration and technical services focused on energy efficient and cost-conscious engineering solutions   

At Certus, we understand the challenges owners face with balancing capital investment capabilities against aging equipment and rising energy costs. We are able to  provide detailed analysis with a multitude of possible solutions to suit our clients’ needs. Through our energy efficient engineering solutions, owners can leverage the best of both worlds. 

The following is an example analysis performed for a typical hospital located in North Texas for the replacement of aged chiller equipment and the expected resulting energy savings. 

Project Scope:

·     325,000 square foot full-service hospital 

·     1,350-ton peak cooling load

·     3-500-ton water cooled chillers

·     3-500-ton induced draft cooling towers

·     Variable speed chilled water pumping

·     Constant flow condenser water pumping

Our team began the assessment by conducting an hourly load analysis using local weather data and coordination with equipment manufacturers to determine initial capital costs of equipment. This assessment provides a basis to evaluate multiple options that will meet the owner’s particular needs. As part of the assessment, multiple chiller efficiency options are being evaluated to determine the best value to the owner. The new chiller options include three options; 1) standard efficiency machines meeting the minimum energy efficiency standards outlined in the 2016 International Energy Conservation Code (IECC), 2) high efficiency machines, and 3) magnetic bearing machines. Each of these options result in an incremental increase in efficiency and cost. The operating costs of each option are evaluated on a yearly basis. The results of the analysis are outlined in the table below, comparing the energy performance and first cost of each option. The return on investment (ROI) represents the simple payback in years needed for the increase in efficiency to offset the increased up-front equipment cost.

This example analysis shows that a strategic selection of more efficient equipment can have a relatively quick payback and continue to save the owner in operational costs over the remaining life of the equipment.

Our goal is to provide the owner with all the tools and explanation necessary to evaluate multiple options in order to determine the best approach for their specific circumstance. At Certus, we are committed to the individual needs of our clients and partner with them to evaluate and implement the technical, energy efficient solutions that provide them the best long-term value.