By SUSAN JONES
The first of several workshops on sustainable practices for your home office — part of the Pitt Green Home Office Challenge — focused on energy efficiency and how to find out if and where your home is leaking air.
“One of the things that we really realized is that if we throw out this Green Home Office Challenge to campus, people are going to have questions about how do I do better,” said Aurora Sharrard, director of the Office of Sustainability.
The Green Home Office Challenge lets Pitt employees take a survey on energy usage and other sustainable practices in their homes to find out their carbon footprint.
Upcoming events include a backyard composting lunch-and-learn from noon to 1 p.m. Nov. 12 (sign up here) and a Recycling 101 lunch and learn from noon to 12:30 p.m. Nov. 17 (registration info coming soon).
Home office energy efficiency
At the first session on home office sustainability on Oct. 30, Lucy de Barbaro, of Rebuilding Together Pittsburgh, talked about why energy efficiency in the home is important and where to make the most cost-effective changes.
Rebuilding Together Pittsburgh is a nonprofit working to preserve affordable home ownership and revitalize neighborhoods by providing critical home repairs, accessibility modifications and energy-efficiency upgrades to those in need, at no cost to them.
When assessing homes, de Barbaro said one of the services Rebuilding Together provides is an energy audit. She recommended using a Building Performance Institute certified energy auditor or Home Performance with Energy Star contractor. An energy audit run around $400 for a typical house. Information on Rebuilding Together's audit program can be found here.
Home energy audits use a blower door to help determine where air is leaking out of the house. The blower is mounted inside the front door frame. Air being blown in pressurizes the house and then the auditor takes measurements to see where the leaks are.
Thermal infrared cameras also are used to “reveal things that that you wouldn’t see with your naked eye,” she said, such as if insulation has settled down to the bottom of the wall, leaving areas uninsulated.
Air also often escapes around rim joists in the basement or into the attic through unsealed light fixtures. These areas need to be sealed before new insulation is put in place, because insulation alone can’t prevent air leaks.
In Western Pennsylvania, insulation should be 16 to 18 inches deep with an R-49 rating. Cellulose insulation, which is made from recycled newspaper, is considered the greenest, Sharrard said, and she said it works better than fiberglass. Another green choice is mineral wool insulation.
Air conditioners with a seasonal energy efficiency rating (SEER) of 10 are 50 percent less efficient than those with SEER of 16. The SEER also will decline with age.
Older furnaces with Annual Fuel Utilization Efficiency of 0.7 use 30 percent more energy than those with an AFUE of 0.95. De Barbaro said Rebuild Together recommends direct vent, sealed combustion models that will bring air in from outdoors and exhaust to the outdoors, to reduce any chance of contaminants being present in your home.
Hot water heaters are responsible for 18 percent of home energy use. A typical tank has an energy factor of 0.5 to 0.6. A condensing sealed combustion gas hot water heater has an energy factor of 0.86 to 0.89. A tankless (1 gallon) gas hot water heater can save 30 percent of energy compared to a conventional model.
Replacing windows is the least cost-efficient way to save energy. They are expensive and if you have ceilings that leak, you’ll still be losing heat. Instead, getting low-e storm windows over your current windows is much less expensive and disruptive.
Susan Jones is editor of the University Times. Reach her at firstname.lastname@example.org or 724-244-4042.
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