In the business of energy efficiency, many often preach about taking care of the “low hanging fruit” first. “Do the low- and no-cost fixes and you will start to see results in energy and money savings right away.” These fixes are often easier and don’t cost a lot, so the facility manager is more likely to get buy-in – and money – from the building owner/board/investor. I have written previously about the low and no-cost fixes, most notably in the article “HVAC Gains with No Budget Pains.”
There is a catch, however: To get the most bang for your buck and the greatest long-term value for your efforts, do not do those low-cost fixes. Not unless you combine them with larger, higher value fixes that may cost some time and capital.
When we do energy audits of commercial buildings, industrial facilities, hospitals or schools, we often find a lot of these smaller, low and no-cost energy efficiency improvements that can be easily made. These might include changing incandescent light bulbs to compact fluorescent or changing from T12 fluorescent lamps to T8s, adding programmable thermostats and lighting sensors, minimizing drafts around doors and windows, moving furniture to improve air flow, etc. - all in an effort to reduce the overall amount of energy the building needs to run.
But sometimes we see major mechanical and HVAC equipment issues, such as faulty valves and steam traps, or dampers that don’t work properly. Sometimes there are relatively simple equipment issues such as Variable Frequency Drives (VFDs) left in bypass, dirty filters, or fans running backwards after a motor change. We often find that the coils in air handling units are so plugged with particulate that they not only restrict air flow and heat transfer, but also may be pouring toxic molds into the ventilation system, making people sick. Coil cleaning can have a dual purpose that benefits everyone.
How do you know if you should hold off on the low hanging, low-cost fixes? If you’ve had a building energy audit done within the last five years but don’t know what else you were supposed to do, or where it is, or what the results meant (these are common!), contact a professional energy efficiency consultant. Preferably one with a background in HVAC and mechanical systems, who is familiar with ASHRAE Standards such as 90.1-2010 and 189.1-2011 as well as ASHRAE Procedures for Commercial Energy Audits – 2011 - and has experience with energy analyses of building systems. (See this article on How to Hire an Energy Auditor.)
If you have not had a recent audit, have an ASHRAE Level 2 energy audit by a certified energy auditor, or an ASHRAE Building Energy Quotient (bEQ) review by a certified Building Energy Assessment Professional (BEAP). Your final report should include all the low-hanging fruit, as a well as recommendations for medium and higher cost items and a ranking of combinations of the lower and higher cost energy conserving modifications (ECMs).
That doesn’t always mean new equipment. One of the most valuable tools we have is retro-commissioning HVAC equipment so it works like new, or in the best manner for the building as it is used today. If your building does require new equipment, you’ll want to make the building energy efficient first, so you may be able to get away with smaller equipment, saving money in both capital and energy costs.
Retro-commissioning, and new equipment if required, have a longer ROI than the “low-hanging fruit.” When you combine these larger investments with the less expensive investments, the overall ROI is more attractive.
Don’t wait. Doing something is always better than doing nothing. But for the biggest impact, do the right thing, and do it today.