As expected, air source heat pumps are super efficient. Energy use in the building seems to be down on an annual basis from 83 kbtu/sqft in 2016 to 58 kbtu/sqft in 2019 - a nearly 31% reduction! ***
Other benefits:
Tenants are now on their own heating systems. They can control temperature in multiple rooms and also control their heating costs.
Everyone has cooling!
No more daily maintenance of the boiler.
We have a community solar subscription for the house common meter and unit three. With that and the solar PV coming from our roof powering the common areas, the building's carbon footprint has plummeted. From 2016-2019, ghg's fell from 145 metric tons annually to 30 metric tons annually - an 79% reduction!
***Methodology - I have been using Xcel's benchmarking tool to track consumption, which I set up prior to the ASHP install and the re-metering of the building. However, the tool only captures electric consumption of units 1-3 but not the house meter. For the house meter, I am using data from our Egauge device that was installed with our PV system. The accuracy of this is somewhat questionable, but seems on an annual basis to be within 5% of the data we see on our Xcel bills. Therefore, it's likely safe to say that the these results have a +/-5% accuracy range. As of 2020.05.17, I am working with Xcel and Egauge to narrow down the accuracy of the data.