by David Lester
If you have shopped at the Co-op in the recent months, you have probably felt a bit like a mouse in a maze trying to find the cheese. With the Water Street Park project and construction crews using the parking lot, we realize that it hasn’t been an easy task to get into our store. But it is all necessary work, and best of all, some of the work has been focused on reducing the Co-op’s energy usage and reducing our carbon footprint.
In March of this year, with the help of Andy Johnson at the Winneshiek Energy District, I created an account with the Environmental Protection Agency’s Energy Star Program. The Energy Star program has been rating appliances, air conditioners, furnaces and other equipment for years, and now has a designation for buildings. A Portfolio Manager account had to be created for our building which includes more than eighteen months of energy data (electrical, gas, water), building data (square feet, # of employees, # of freezers and refrigeration units, computers, etc.), and a written explanation of work that has been done on the building to make it more efficient. The last step was to have all of this data confirmed by an Engineer and/or Certified Architect and then the building is ready for the application process.
Our building was approved for Energy Star status in early May. We are in the Grocery Store category and we are the only Co-op in Iowa with this status and only one of four grocery stores in the state with this status. We achieved a score of 98 out of a possible 100 with only one HVAC unit and an un-insulated roof! Our store practices make us a very efficient grocery store, but we weren’t satisfied with a building envelope that didn’t hold our heat or conditioned air. The staff and I wanted the Co-op to be a leader in our community for energy efficiency as well as be prepared for continued rising energy costs.
One of the benefits of working with the Winneshiek Energy District on this project was getting a professional energy auditor into the store who can help pinpoint “the low hanging fruit.” These are the items that we could implement easily to reduce energy usage and to present a plan to make our building more efficient with the most payback. After the audit, it was obvious that our heating and cooling system was undersized and needed to be upgraded. We now have two new efficient roof-top units providing the store with heat and cooling. We can monitor and control these units through a website and I receive alerts to my email and cell phone when there is a problem or issue with the system. Within a few seconds, I can make changes to the system from anywhere in the world, as long as I’m near a computer with internet access.
Two other issues were building envelope/insulation and our tunnel-heat recovery system. Those of you who have been in our store during the summer know about the negative air pressure that we have had to deal with, which is especially noticeable in the entryway and the rear entrance to the building.
We just completed the new roof project, which happened to coincide with the hottest week of the year so far. Our old roof consisted of one-inch of plywood and a gray rubber roof membrane. The R-value was minimal, probably single digits. We chose a roofing contractor that would impact the environment as minimally as possible and provide us with quality materials and offer this service at a good price. We did not tear off the old roof and basically built a 7-inch, insulated roof on top of the old one (R-value of 42). Our contribution to the landfill was very minimal (about half of a dumpster) and we had one member reuse all of the old tin flashing pieces that came off the old roof. The insulation itself was reclaimed from other building projects that ordered too much and would have gone into the landfill or not used. The roof membrane used is a pure white, rubber membrane that was sealed with heat instead of adhesives or glues.
As for the store vacuum situation, I have to thank Co-op member, Dale Kittleson, for his ingenious thinking about this issue. After meeting with Dale I contacted Casper’s Plumbing and Heating about our idea to let more air into our tunnel-heat recovery system that houses most of our freezer and refrigeration compressors. To make a long story short, it works. There is no more air being sucked out of the store and the doors leading to the hot, humid conditions outside do not open. Whew.
I am happy to report that during our last billing period (June 15-July 15) we used 6,900 KWH less of electricity compared to the same period last year, about 11% less. We used 90 ccf (hundred cubic feet) less of gas during this same period compared to last year, about 18% less. Things seem to be working like we planned and I look forward to tracking this data through the Energy Star site.
Now that these projects have ended and our store is a more inviting and comfortable space, the path to the cheese is a lot easier. Thank you for still shopping with us during this construction period and I look forward to seeing you in the store.