DN20 Ultrasonic Heat Meters (3/4”)

DN20 is the most commonly used heat meter size in apartment installations with manifolds. On this page you can compare the DN20 ultrasonic models of seven brands side by side.

DN20 Heat Meter Dimensions

DN20 corresponds to a 3/4-inch pipe size. All DN20 models with a technical table give a nominal flow rate (Qn) of 2.5 m³/h, a body length of 130 mm and a 1” connection thread. Because these dimensions are the same across brands, an old DN20 meter can easily be replaced with a model from another brand; we still recommend measuring the length of the meter to be removed. The real differences in selection come from the application (heating only or heating/cooling), the communication and MID approval.

Models and Key Differences

• Novus Digitermo DTL-DN20 – made in Türkiye, heating/cooling, M-Bus
• Minol Zenner C5 IUF DN20 – M-Bus or RF (wM-Bus) selectable, heating/cooling
• Calmet PM02-DN20 – heating/cooling, M-Bus
• Cem CM-HR DN20 – made in Türkiye, heating/cooling, M-Bus
• İntegral UK-PLUS DN20 – built-in wired M-Bus
• Danfoss SonoSafe 10 DN20 – heating only, M-Bus, battery 16+1 years
• Honeywell DN20 – heating only, M-Bus

Other sizes: DN15 · DN25 · DN32 · DN40 · Large diameter (DN50–DN300) · DN20 mechanical

Frequently Asked Questions

How many inches is a DN20 heat meter?

DN20 corresponds to a 3/4-inch pipe size; the connection thread on the meter body is 1”, and the meter is connected to the installation with unions.

Can a DN20 heat meter of a different brand replace the old meter?

Yes, if the body length and connection thread are the same; the technical tables on our site give a DN20 body length of 130 mm. In buildings with remote reading, the communication type of the new meter (M-Bus or wM-Bus) must be compatible with the existing system.