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?
Lighting
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: http://www.30minuteeit.com