Commercial brokers must be knowledgeable about many different disciplines: law, construction, engineering, finance, negotiation, and more. This week, we continue our “Going Green” series with an expert post by a HVAC expert. Stay tuned, next week, for information about commercial cleaning.

The following is a guest column by George Peters, LEED® AP, Senior Mechanical Engineer for the H.B. McClure Company.

“Green Building” is a broad term which has many different interpretive definitions, depending on one’s professional perspective.  Mechanical contractors are often asked to provide green options to clients.  This poses some difficulty in meeting that expectation, without first reaching collective agreement on the goal.  Our challenge is to help building owners meet today’s advanced comfort needs without ignoring tomorrow.

Generally speaking, most mechanical goals fall into two categories;:reducing energy use (expense) and conserving water. Owners’ financial budgets and their personal motivations combine to determine ‘how green’ a particular project will be. In most cases as you slide up the green scale the installed cost increases while the annual operating expense decreases. This balance between first cost (budget) and operating expense (payback), when coupled with owners’ expectations, is the equation that needs solved for a project to be successful.

To some, ‘green’ means employing renewable energy technology provided by geothermal or solar equipment.  To others it simply means approaching the project to maximize efficient energy usage.  In today’s economic conditions it is imperative that we look at the entire building, as system.  Building insulation and envelope, lighting strategies, and the mechanical system design all play a role delivering to clients a property that is environmentally responsible, comfortable and financially efficient to own and operate.

Not every construction budget can afford THE most efficient system.  But there are several incremental steps that can be taken on even the most basic HVAC system approach to enhance operational performance and achieve some measure of sustainable, green building objectives.

First, consider upgrading from the base low-bid equipment.  Most manufacturers offer high-efficiency alternatives to conventional rooftops and split systems.  For a very modest additional cost, investing in equipment that exceeds ASHREE/DOE minimums can yield large savings over the life of the system.    Increased comfort and much lower operating costs can be achieved in the use of multiple-stage equipment that matches the demand load during non-peak conditions.

Next, explore the benefits of integrating a controls strategy into the system.  Huge operational efficiencies can be gained by staging and/or modulating equipment when applied to an intelligent Building Automation System (BAS).  Temperature setback, thermal averaging, and zone priority offset are a few strategies employed to reduce peak electric demand and limit energy expenses.  Demand fresh-air ventilation control provides excellent comfort and indoor air quality (IAQ) at lower operating costs. Also remember to consider the space set-point temperatures. Raising an AC set-point 1 degree not only saves operating expense, but might allow a reduction in the overall capacity of the unit, thus reducing the first cost.

Owner-occupied projects typically can be approached differently than those being built by 3^rd party real estate investors.   A client with a shared interest in not only the long-term debt service for construction costs, but the on-going building utility expenses as well as is more likely to look at the life-cycle costs of system ownership.  Schools and senior-living projects are examples of this type of project.

In these instances, a compelling case can often made for investing in high-end renewable energy systems such as geothermal.  In viewing these systems on a cash-flow basis it is not uncommon to show that the operating cost savings exceed the additional financed expense of the upgraded costs.  When viewing the additional system costs as a return on investment (ROI), realized payback of less than five years is possible.

Long term satisfaction with any system, including a green system, requires quality control and maintenance. Quality control, also termed commissioning, helps insure that the system designed is actually installed. Maintenance, or more specifically preventive maintenance, starts with the completion of construction and continues for the life of the building, with its goal being the continued efficient operation of the systems. Neglected systems will degrade over time and increase the service and operating costs.

The ultimate selection of a ‘green’ mechanical system is a collaborative result of communication between the client and mechanical system engineer.  Energy saving components need to be financially weighed to ensure they are viable. This is the key to creating a successful strategy for sustainable design.

George Peters, LEED® AP is the senior Mechanical Engineer for the H.B. McClure Company. He has held this position for over 15 years and has been responsible for designing and building over 400 facilities that utilize geothermal energy and water sourced heating and air conditioning technologies.  George is also heavily involved with the local ASHRAE and USGBC Chapters where he contributes his time and leadership to raising the bar on efficiency in green buildings.