Building Energy Efficiency: What Matters Most?
Joel Erway posted on June 03, 2013 |
3 keys to reducing energy use in commercial buildings

Greening commercial buildings is one of the most important ways to conserve energy. It’s also a major market for companies that produce low-energy products.

Facts (source: Energy Star):

                        - There are over 5 million combined commercial and industrial buildings in the         U.S. alone

                        - Combined annual energy costs for these buildings: $200 Billion

                        - Portion of energy in buildings used inefficiently or unnecessarily: 30%

The main uses of building energy are lights, heating/cooling equipment, and heavy industrial processes. So where is the lowest-hanging fruit?


An easy calculation for quick upgrades is to analyze the energy consumption of an LED (as low as 2Watts) versus an incandescent light (60W). That equates to around 1/30th the cost for electricity. Scale this for an entire commercial building and you have a major savings.

Caveat? LEDs are much more expensive on a first-cost basis, and require significant labor to replace all bulbs in an office building. That said, this is an easy cost-benefit analysis to make.

Heating & Cooling

What about heating and cooling? There are lots of ways to condition a commercial space, so the opportunity for energy savings depends on what's available. Is natural gas available for combustion heating? Is there 3-phase power for a compressor system? Is there a central chilled water plant and boiler plant?

For energy efficiency we need to look at energy recovery - using existing heat within a space to transfer to the central heating/cooling process. This reduces waste conditioning that would normally be dumped back into the atmosphere. The technology is pretty standard in new buildings, but cost-effective retrofits should be analyzed.

Construction Materials

Finally, construction materials play a major role in energy conservation. Solar gain through windows, sustainable materials, sun shades, and louvers are critical for a building's energy reduction. Are these materials readily available locally, and is there a premium for contractors who are certified to install these materials. Is it worth the premium and payback?

So, what have you found to be the most economical, reliable, and/or feasible ways to produce “green” buildings?

 Joel Erway, EIT is author of 30MinuteEIT. To read more regarding engineering, see:

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