Are Gas Furnaces and Boilers the New Diesel Cars?

The age of diesel and petrol cars is ending. It’s time to do the same for fossil fuel heating.

It's hard to convince anyone in North America about the evils of gas furnaces (or boilers, as they are called in Europe where most people heat with hot water) when gas is so cheap and the industry has done such a good job of brainwashing us about how clean it is. And it is true that it is lower in CO2 emissions than any other fossil fuel.

Energy Information Agency/Public Domain

However, it still pumps out 117 pounds of CO2 for every million BTUs of heat generated, and the US burned 4.78 quadrillion BTUs for residential heating, hot water and cooking in 2016. That's a lot of zeros and a lot of CO2. Gas furnaces and boilers also last a long time, so if any change is going to be meaningful, it has to happen soon.

Writing from Brussels, Adrian Hiel asks Are gas boilers the new diesel cars? He notes that his old diesel car is no longer allowed on streets where he lives, thanks to new Low Emissions Zones (LEZ), and wonders if the same kind of action needs to be taken with gas appliances.

In the Netherlands they have a clear deadline for getting out of gas by 2050. According to our Dutch members this has greatly helped, and slightly complicated, the conversation with their citizens. Gone are the discussions about simply trying to make current systems more efficient and in their place is a clean slate of new and transformative options.

Basically, he is calling for Low Emissions Zones for buildings as well as cars. But as I found with my own house when I renovated five years ago, you can't just swap out a gas boiler for an electric heat pump without your energy costs going through the roof. He points to a post by Jan Rosenow, who replaced his gas boiler with a heat pump and notes:

It is important to note that installing a heat pump in isolation in existing, and often inefficient, homes is not advisable. I have made the argument elsewhere for aligning energy efficiency and heat decarbonisation to maximise carbon reduction and avoid oversized heating systems. This is why we invested in energy efficiency measures in our Victorian 1880s home alongside the heat pump. We insulated the floor throughout, installed mostly triple or double glazing and insulated the attic.

My super-efficient gas furnace/ Lloyd Alter/CC BY 2.0

This gets expensive, which is why I didn't do it. Instead, I bought the most efficient boiler I could find and got some new storm windows for the leakiest old windows. I realize now what a short-sighted decision that was, given that I am now "locked in" to gas for the foreseeable future.

Back in Brussels, Adrian Hiel writes that we need a neighborhood or "renovation wave" approach to fixing our homes and changing our heating and creating Heating LEZs.

Heating LEZs and the Renovation Wave are complementary. Fitting a heat pump or building a district heating network for drafty and under-insulated homes is not resource efficient. With a neighbourhood approach to the Renovation Wave property owners can get the support they need to upgrade their buildings and then make the switch to a heat pump or other low-carbon heating options. The virtuous circle here is that the Renovation Wave should also include the expansion of community energy programmes to power heat pumps with local green energy and make a significant local socio-economic contribution in addition to driving emissions down further still.

The age of diesel and petrol cars is ending. It’s time to do the same for fossil fuel heating.

One can see this being done in cities like New York or Chicago for multifamily buildings, but the cost of fixing all those sub-standard single-family houses would be huge. And would it make that much difference? Looking back at that graph for residential consumption, residential buildings are now consuming more electricity for cooling than they are gas for heating.

Energy Information Agency/Public Domain

Meanwhile, the American electrical grid is still 65 percent fossil fuel-powered, and won't be switching away from gas for a while when the frackers can't give the stuff away.

As architect Sheena Sharp has noted, the electricity that comes into our house can get cleaner over time. Where we both live in Ontario, there is no more coal burned and just a little bit of gas burned in peaker plants. So a first step might be to ban all installations of new gas boilers or furnaces in new homes.

But just as we have said that switching all our cars to electric doesn't solve some of the fundamental issues with cars, the fact remains that just switching all our furnaces to electric heat pumps doesn't solve the larger problems of density, urban design or overall energy consumption. Unlike Brussels and other older cities, North Americans live in places that appear to be designed to promote burning energy, from the car dependence to the five exposed sides of single-family houses.

Or as I noted in an earlier post, we have to Reduce Demand. Clean up electricity. Electrify everything.