Take Charge of Your HVAC Design for the Good of the Environment

This summer, we have seen record-high outdoor temperatures, drought, and numerous wildfires throughout the world. Little concern is given to these issues, and they are not receiving the attention they should get from our government now or in the past. Listening to a scientist “tell it like it is,” he said, “It is too late to reverse climate change. We can only stop climate change.” So, this got me thinking back to when the energy crisis was identified in the early 1970s. I chose to be proactive and responsible.

Back then, I was the design engineer for a major new high school project scheduled through a design-bid-build delivery. No construction manager or estimating consultant was assigned to assist with the project budgeting in the design phase. Back then, the design engineer was responsible for producing the HVAC budget estimate. I also knew that any HVAC “frills” (aka embellishments) would not go over well with the lead architect because any funding for such frills would be used for aesthetics and not a more energy-efficient mechanical system, even though we were experiencing an energy crisis for the first time. If I wanted to present energy and/or environmental savings, I would have to submit an analysis based on an acceptable return on investment (ROI) before the lead architect would possibly consider the idea(s).

In the years leading up to this specific engineered solution for the high school project, I routinely listened to mechanical contractors on “what design engineers did wrong,” e.g., design sheet metal layouts requiring an excessive number of fitting, transitions, etc. I was told by a sheet metal estimator that, when estimating a job, he would carry as much as 35%-40% sheet metal waste from cutting/fabricating transitions and reduction pieces. A piping estimator told me if he could, he’d maximize the gallons per minute (gpm) flow within a pipe size before moving up to the next pipe size. This was especially important when going from screwed pipe to welded pipe. A third recommendation was to “package the equipment” whenever possible, basing equipment selections on what a select few equipment manufacturer representatives sold rather than basing individual HVAC equipment from various equipment vendors. This would allow the mechanical contractor to negotiate the bulk of equipment through as few manufacturer representatives as possible, allowing the contractor to get the best price in the buyout.

I applied these lessons learned and, in turn, incorporated the following energy-conserving equipment into my design based on two estimates I generated. The first estimate was a traditional estimate using budget values. The second estimate was based on “value-engineered” costs and the inclusion of the following:

• Five energy recovery wheels that preconditioned the summer and winter season outdoor air. Today, these enthalpy wheels are standard HVAC features when it comes to energy conservation. No ROI is needed; and
• Surround each kitchen hood perimeter with continuous linear supply air makeup at the hood, allowing the outdoor air to be introduced at cooler heating season supply air temperatures and warmer summer air temperatures. A byproduct of this configuration was the air-curtain effect that contained the heat from the grilles and prevented it from radiating this heat into the occupied space. The cook also had access to a temperature controller to adjust the supply air temperature for personal comfort.

These two major energy conservation measures, along with other cost savings engineered solutions, resulted in a budget estimate at approximately the same total estimated cost as traditional design engineering. When the final contractor bids came into the architectural firm, the energy-conserving design was less than 1% over the tradition price, and the lead architect still did not know what energy-saving features were in the project.

From this job, I wrote my first published case study article, “Energy Conservation Through Value Engineering,” in 1976. The story was picked up and published in a book, titled, “Handbook of Energy Conservation for Mechanical Systems in Buildings” in 1978.

So, what is my point? Take charge of your HVAC design for the good of the environment. Make the project’s engineered solution be responsible through value engineering rather than as an HVAC alternate based on an ROI. Be proactive and a leader. Do the responsible thing and not the traditional thing.