Heat cost allocators for the determination of the consumption of room heating radiators. Appliances with electrical energy supply|Radiators, Heaters, Rooms, Hot-water central heating, Central heating, Space-heating systems, District heating, Energy consumption, Costs, Meters, Heat measurement, Temperature measurement, Temperature-measuring instruments, Thermal output, Thermal measurement, Electrically-operated devices, Environment (working), Probes, Performance, Errors, Ratings, Maintenance, Heat ageing tests, Testing conditions