DeKALB, Ill. — If you are a contractor up to speed on such subjects as geothermal, variable-frequency drives, setback and reset controls, economizers, sensors, and the like, then you are a big player in efforts to make buildings green and hold down costs while doing so.

The role of air conditioning and heating contractors — as well as those in the refrigeration sector — also played a big part in a seminar called “Going Green and Paying for It: Green Tools for Municipalities” presented by the Illinois Chapter of the United States Green Building Council (USGBC) and held in the Engineering Building on the campus of Northern Illinois University.

Although portions of the seminar centered specifically on issues related to funding and construction in Illinois, large portions of the presentations focused on topics that had national applications for HVAC contractors.

Reduce, Recommission, Renew

For example, Josh Greenfield, associate vice president for Primera Engineers, noted HVACR tasks such as changing filters, coil cleaning, and duct sealing are the “fruit on the ground” in terms of an extremely low-cost way that building owners can improve efficiencies to save energy costs.

Greenfield discussed this during the “Renew” part of a talk he called “Reduce, Recommission, Renew,” with HVAC showing up in all three parts. According to Greenfield, “Buildings represent 40 percent of the natural gas and 70 percent of electricity used in the United States. Approximately 86 percent of building construction expenditures relate to renovation of existing buildings, not to new construction. It is estimated that over the next 30 years, about 150 billion square feet of existing buildings (roughly half of the entire building stock in the United States) will need to be renovated. New construction only represents about 2 percent of U.S. commercial building stock.”

Next Greenfield discussed recommissioning, which he described as the “low-hanging fruit” or the “coconuts.” Continuing his fruit analogy, Greenfield noted that coconuts “are somewhat hard to get but worth it.” Then he applied this to HVAC, and noted that examples of this include “equipment efficiencies, outside air quantities, setback/reset controls, economizers, and humidification/dehumidification.” Also in the mix in many buildings are “refrigeration, motor efficiencies, and controls.”

In the category of “Renew,” Greenfield pointed to more “coconuts” such as “solar photovoltaic, solar thermal, solar ventilation, horizontal axis wind turbines, and vertical axis wind turbines.”

He also touched on ground source systems, asking, “Is ground source geothermal renewable?” For an audience made up mainly of architects, engineers, and municipality officials, Greenfield went into more detail regarding geothermal technology that many HVAC contractors are involved with.

“Vertical fields are ideal in urban environments because they utilize a smaller footprint when space is at a premium. A common well field consists of several vertical bores that are about 6 inches in diameter spaced 20 feet on center. Spacing between bores maintains a stable ground temperature throughout the life of the field. The actual depth of the wells usually varies from 300 to 600 feet deep, depending on the contractor and site conditions. The depth of the field, grout type, and soil conditions will affect the amount of energy delivered to the building. For every 130 to 200 feet of borehole drilled, a building will gain 1 ton of cooling.

“Lake or pond loop systems involve coils of pipe, or a submersed heat exchanger placed in a body of water. This type of system can be very economical when a large body of water is available.”

In terms of which to choose, he said, “All geothermal systems consist of two parts: the ground loop heat exchanger (or well for pump and dump systems), and the heat pump and the distribution system inside the building.

“Regarding ground loop heat exchangers, there are significant state and local restrictions and there is potential for damage since the loop system could be exposed to boats, animals, etc. Horizontal loop requires a large area, the installation is disruptive, and the horizontal systems are more affected by soil type and moisture content. Vertical loop is the most expensive type of ground source heat exchanger system and can be even more expensive in areas where rock drilling is required. However, it requires the least amount of area to install and therefore can work in almost any situation.”

Facility Improvements

A presentation by Becky Werra, account executive — energy and environmental solutions for Siemens Industry Inc., focused on procurement and financing options for facility improvements and also factored the HVAC contractor into the equation.

Citing funding through the Illinois Clean Energy Foundation, she noted ILCEF recognizes energy efficiency through “model energy-efficient systems, high performance green buildings, design and commissioning, and existing building energy efficient improvements.”

Within the category of innovative HVAC, there was recognition for “air-to-air heat recovery dehumidification, high-efficiency dehumidification HVAC systems, and high-efficiency modular centrifugal chillers.”

Another funding assistance source, the Department of Commerce and Economic Opportunity (DECO), recognized “new standard incentive program categories including HVAC, water heaters, and motors” as well as “increased incentives for electric air conditioning equipment with new incentives added for natural gas furnaces and boilers and ground source heat pumps.”

Publication date: 01/09/2012