The standard calculations that HVAC contractors use to size heating equipment are an obstacle to electrifying the space heating sector. The reason is that they consistently project much higher heating loads than most homes ever experience, causing contractors to install much larger equipment than is necessary.
That practice isn’t a big problem for natural gas furnaces. Larger furnaces cost only a bit more than smaller units. They may operate a bit less efficiently, but those contractors aren’t paying the utility bills. But for heat pumps, larger units cost significantly more than smaller ones and oversized equipment can run much less efficiently.
How can contractors and homeowners ensure that heat pumps are accurately sized? New calculation methods are emerging that use data freely available in existing buildings, from utility bills and smart thermostats, and have the potential to be not only faster and cheaper than the standard calculations, but also produce more accurate results.
There are some imposing barriers holding back the widespread use of these new data-based calculation methods. There are few studies demonstrating their accuracy, no national standards for their application, and no model building codes that explicitly approve them. The good news is that researchers and advocates are working to overcome all of these barriers.
To learn more about data-based heat pump sizing calculations, how to apply them, and the researchers studying them, click below.
https://energytechnologyrevolution.com/for-heat-pumps-size-matters/