FAQs
Last updated: October 29th, 2026
COP
Why do some heat pump vendors advertise a COP of 8 or higher, and why doesn’t that number apply to most real industrial applications?
COP (coefficient of performance) is essentially the overall efficiency, or “fuel rate,” of a heat pump, and it plays a big role in a project’s overall economics. But a very high COP, like 8, usually shows up only when the “lift” is small. The lift is the temperature difference between the heat source (where you are absorbing heat) and the heat sink (where you are using the heat). If a heat pump is raising the temperature by just 5 degrees Celsius, the COP can reach 30 or more, but there aren’t many applications where that is valuable to a customer.
AtmosZero is built for the other end of the spectrum: high-lift applications that create real value for customers. For example, consider taking heat from a chilled water system at 55°F, where you must reject heat for the system to work, and then using that same heat to make steam at 300°F. That is a valuable use case we see commonly across industries, but the lift is 245°F. In a high-lift application like that, the COP physically cannot be 8. A better way to compare heat pump technologies is Carnot efficiency, which measures how close a system gets to what is physically possible. COP numbers depend heavily on the application and how much temperature lift is required, so Carnot efficiency is the fairer yardstick.
Why does AtmosZero’s COP change with pressure and temperature lift, and is that normal for any heat pump?
Yes, and it’s what you should expect from any heat pump. In a steam system, pressure and temperature are directly related. At 15 PSI, steam is 120 degrees Celsius. At 60 PSI, it’s 150 to 153 degrees Celsius. The exact numbers shift with altitude, but the relationship between pressure and temperature is direct.
The heat source side can move too. If you’re sourcing heat from outdoor air, for example, your lift changes throughout the day. Because the source temperature and the steam pressure both shift, a heat pump produces a range of COP values rather than one fixed number. That’s why we show COP as ranges and on a graph. Performance comes down to the lift and how much electrical work the compressors are doing.
Electric boilers
What’s the real difference between AtmosZero and an electric resistance boiler?
An AtmosZero heat pump moves heat from point A to point B. An electric resistance boiler converts electricity into heat. That is the fundamental difference, and it shows up in efficiency.
An electric boiler runs at about 98 to 99 percent efficiency. A heat pump’s efficiency is its COP multiplied by 100, so a COP of 2 means a 200 percent efficient process. A heat pump gets past 100 percent because it moves heat rather than converting one form of energy into another.
When does a heat pump make more economic sense than an electric boiler, and when doesn’t it?
Electric boilers have a place in the market, and so do heat pumps. There is some overlap, but the two generally suit different applications. The deciding factor is how your heat demand behaves.
A very volatile demand, such as needing a lot of heat for one hour and then none for the next 23, is a strong electric boiler application. A hospital sterilizer is a good example: instruments go into the autoclave, it runs for a couple of hours, and then it sits idle until the next surgery.
A heat pump is the opposite. It wants to run all the time, and the more operating hours it accumulates, the better the return on investment. A food and beverage manufacturer with a line running 24 hours a day, and steam needed across ten different processes, is a good heat pump application.
More questions? Send them our way: info@atmoszero.energy