By Carolyn Goldthwaite | Wed, June 16, 21
Mittens, where are my mittens - I’m freezing!
That might be a familiar refrain during winter months in New England, but this time, it was Memorial Day weekend! I woke up at my parents’ house in New Hampshire to a cool 43 degrees – on May 29! Thankfully, they have air source heat pumps that are keeping the house warm, and I soon forgot about my mittens and focused on a hot cup of tea.
Fast forward to June 7 and I was back at my cottage in Maine and it was already 80 degrees out at 8:00 a.m. That cool ocean air didn’t save me on that day. I put in the window AC unit.
On the morning news, schools across Southern Maine dismissed students early or canceled school altogether. As the number of 90-degree days steadily climbed in the region, cooling centers began to open as a way to help people cope with the heat — a serious health threat, particularly for the elderly. And it’s still not even officially summer.
Weather Roulette
45 – 90 – 60. The weather in New England this spring has felt like a game of roulette – spin the wheel to see where the temperature lands. We experienced a low of 45 and a high of 93 in the span of a single week. We went from heating to cooling and back to heating. As strange as it is, this is becoming the new normal for many of us this time of year.
According to the Environmental Protection Agency (EPA), the rising global average temperature is associated with widespread changes in weather patterns. Scientific studies indicate that extreme weather events such as heatwaves and large storms are likely to become more frequent or more intense with human-induced climate change.
In order to combat climate change, President Biden has set a goal of lowering U.S. greenhouse gas emissions 50-52 percent below 2005 levels by 2030. Meeting this target will require rapidly converting as many fossil fuel-powered activities to electricity as possible. New heating and cooling strategies are an important piece of the puzzle. An air source heat pump can provide efficient heating and cooling for homes, but is that the solution for everyone?
Do Window Units Have a Role in the Future of Cooling AND Heating?
I want more from my window AC. This is something I have been wondering about for the last few years. In my cottage, I have a window AC for cooling and a small propane stove for heating. Why isn’t there an affordable solution for something that heats AND cools? Why can’t a window unit or a portable AC unit provide heating too? I know portable ACs and window units are not the most efficient solution, but for some, it may be the only solution.
Now before you freak out and yell – Carolyn, split system heat pumps! – let’s think about this for a moment. Yes, split system heat pumps are a great solution for many applications. I get it, NEEP has spent a great deal of time working to educate and expand the split system heat pump market. I have mini-split heat pumps in our house in Massachusetts. In 2018, we did a deep energy retrofit – gutted the house, opened up all the walls, added spray foam insulation, new windows, updated electrical, plumbing, and added heat pumps as our primary heating source. I love how quiet they are, the money I am saving, and that they provide cooling too (something that was missing in my old home). But this process wasn’t affordable. And it’s not a practical choice for everyone.
An Alternative to Split System Heat Pumps
There are three things necessary to install split system heat pumps – space, an electrical system that can handle the capacity, and the funding to have them installed. This can be an impractical choice in urban settings filled with apartment buildings. We’ve all seen them – the high-rise city buildings with window AC units all over the place.
Emerging in the market is the idea of replacing existing window cooling-only units with heat pump window units that can cool AND heat. Creating these units would be a small jump in cost but deliver a new electrification opportunity. Currently, there are virtually no heat pump versions for existing window AC units – but there could be.
We’re already seeing a similar movement with the packaged terminal air conditioner (PTAC) market. PTACs are the units often found in hotels that sit under the window. Historically, these products would provide cooling and heating, but the heating relied on very inefficient electric resistance. Leading manufacturers have recently begun designing these system to operate as heat pumps. Window AC units could also be manufactured to include efficient heating. This represents a small piece of the market right now but could offer a more equitable solution, especially for those in historically marginalized communities.
In New York City, 65 percent of apartment buildings use central HVAC systems but many do not have working air conditioning. Retrofitting our older building stock is expensive and in many cities like NYC, there often isn’t space to run or install complex systems. It’s a high cost to replace these systems so in go the window AC units.
It’s time to innovate and think differently about how we heat and cool our homes and buildings. We need affordable solutions for all.