With a window of just five days to reach 40% energy savings, the retrofit work continued today, despite the rain in D.C. The dedicated HVAC crew overcame slippery roofs, cramped closets, and decades old equipment in installing new, high performance heat pumps. Old heat pump units had a nameplate cooling efficiency rating of 13 and 10 SEER, and were expected to have even lower efficiency performance due to the age of the equipment and lack of regular maintenance. In fact, one of the units had a date of 1979 on its wiring diagram, which just happens to be the same year that Sony released the Walkman. Time for a change out, anybody?
The new units are rated at over 17 SEER in cooling, with a heating season performance factor of almost 9. While both interior and exterior units are set in place, there are a couple more details to finalize before the new heat pumps are up and running: installation of condensate pumps (as required by code), digital programmable thermostats (allow you better resolution than a +/- 5 degrees Fahrenheit set point), and drain pans.
We also completed the installation of state data loggers on each window within the home – over 30! The loggers will record window open/closed operation, which can be overlaid with heat pump energy use to determine if the building is being managed efficiently (i.e., no heat pump operation when windows are open), or if there are opportunities for greater energy savings through better window management. And no, unfortunately the loggers do not beep or ask, “Do you live in a barn?” when tripped.
After a long day of work, Sasha Bruce and the Home Builders Care Foundation hosted a reception to provide some education on the project and give us an opportunity to thank Walmart, HomeAid America, and the Department of Energy for their generosity in making this project a reality. Staff were excited to hear that they could realize up to 45% energy savings at the home once the retrofit is completed. And the residents were especially excited to eat
brownies before dinner.
On deck: Tomorrow should see the completion of the ASHP installation and the beginning of air sealing efforts. It will be interesting to see what we find in the attic, as part of this home was constructed before the turn of the century. Yes – that’s the 19th century, kiddos. We’ll keep you posted.