In late 2019, I finally began to upgrade my early 20th century-built, Palo Alto home. I had three goals: to improve indoor comfort, decrease energy costs, and reduce my carbon footprint. Replacing doors and windows seemed like a good place to start: my property abuts Caltrain and multi-pane windows substantially suppress sound. I contacted the City of Palo Alto’s Home Efficiency Genie group for an initial consultation and inspection, but COVID hit and inspections stopped.
During the early days of the pandemic, I was able to replace the doors and windows. I visited several local residential construction supply companies to learn about products and assess options. A colleague recommended a local contractor who had worked on his home. I chose a supply company, picked doors and windows, and we were off. This all happened during early COVID, so we took care to minimize possible exposures during installation. The work went smoothly, and I soon had a much quieter, more temperature-stable home.
Replacing my gas water and space heaters, along with my gas stove with heat pumps and induction cooktops, could decrease both my energy costs and carbon footprint. Palo Alto encourages electrification—they make it easy to cut off natural gas; there are rebates available for equipment like hot water heat pumps.
To minimize global warming impacts, I wanted to get a heat pump water heater that used carbon dioxide as a refrigerant instead of common, hydrofluorocarbon versions. (Yes, CO2 is a greenhouse gas, but common refrigerants tend to warm 100 to several thousand times as much per weight). Through the City of Palo Alto’s website, I found a list of local vendors and installers, one of whom sold and installed with CO2 heat pump water heaters. I stayed with them for the HVAC heat pump system.
Installation was delayed a few months—a new version of the heat pump water heater was coming out, and it was backordered. When the heater arrived, it, along with the HVAC unit, was installed in a bit over a week. There were a couple of problems during initial use:
- When started, the heat pump water heater would heat water to the set point and turn off but wouldn’t turn on again.
- The indoor air temperature sensor on the air conditioning/heating controller was defective.
The first problem caused considerable head scratching—it turned out there was a loose screw. A new controller solved the second problem. Since then, everything has worked fine. I also quit using my gas stove. During the 10 months since the heat pumps came online and I’ve gone all-electric, my energy costs have dropped by about a third (comparing September 2021-June 2022 versus September 2020-June 2021 costs). But the 10-month drop covers only about $300 and doesn’t include expenditures associated with switching to all electric cooking. Fortunately, my house included an electric oven. After spending around $300-400 on induction compatible cookware and an induction cooktop, I was fully operational.
Was the expense worth it? I’d say yes. The house is more comfortable and valuable; my carbon footprint is also a bit smaller. Plus, most of what I replaced was getting old. Palo Alto has a mild climate and gas/electricity rates are moderate. Where winters are cold, summer hot and humid, and/or rates higher, the savings would likely be significantly greater.
Cover image credit: Anna Haefele
