Heat meter
A heat meter (also called a thermal energy meter or BTU meter) measures how much heat a system provides. It does this by measuring the flow rate of the heat-transfer fluid and the temperature change between the supply and return lines. This lets building owners bill tenants based on actual heat use (submetering). Heat meters are common in district heating and other shared systems, and they’re also used in industry to measure boiler output or process heat, and in solar thermal systems to verify energy collected.
A typical heat meter includes sensors, a flow meter, and a calculator that converts flow and temperature change into energy use. For remote readings, many meters use the Meter-Bus standard. In Europe, meters used for energy transfer must meet the Measuring Instruments Directive (MID) Annex VI MI-004.
Terminology and history: In the United States and Canada, these meters are usually called BTU meters and have been available since the 1950s. They’re less common today but interest is growing with higher energy costs. The European Union promoted per-tenant metering starting in 2002 and made it mandatory in 2012 for many multifamily buildings with district or central heating.
Regional notes: Northern China installed millions of heat meters in cities with district heating by 2015; by 2024 charging per household based on heat use was not yet widespread but was increasing. Russia has a large district-heating network, with meters in a portion of private and public buildings.
This page was last edited on 2 February 2026, at 14:05 (CET).