The heating cost bill comes once a year. Awaited by many with mixed feelings, it is in fact an important tool for tenants to help them save energy and therefore money as well. But why is that so? We went in search of the reasons.
Tenants in Germany have received an individual annual bill for their heating since the beginning of the 1980s. Those who get money back from their monthly payments are delighted. But those who have to pay extra are less pleased. In any case it is worth taking a closer look at the heating bill. For since its introduction, each household only pays for what it actually consumes. And that pays off: the European Commission estimates the energy-saving potential of heating cost billing in the building sector to be 15 to 25%.
“This transparency is a huge benefit for tenants,” explains Ralf Schäfer, product manager at the real estate service provider ista. “It is easy for people to see their own energy use behaviour from the heating bill. They only have to compare their current consumption with the previous year’s figure. People who see they have used a lot more in the last year tend to use energy more sensibly in the future and therefore save money.”
Impossible without heat cost allocators
One way of billing a large number of tenants is to measure heat consumption directly in the apartments. To do this, ista mounts on every radiator a so-called heat cost allocator that measures the radiator surface temperature and the length of time heat is emitted. The devices are equipped with a scale or a digital display. But remember: the figures displayed are not the amount of heat consumed but merely abstract measurement readings.
In order to allocate consumption properly, these readings have to be assigned to all the tenants in a particular ratio. To do this, the individual meter readings are first multiplied by a conversion factor that takes the capacity and design of the particular radiator into account. Each apartment’s share of the total heating costs of a building can then be determined.
Electronic + Wireless = Added Value
Generally speaking, heat cost allocators operate in different ways. The analogue type of device operates using the evaporation principle. A liquid in a small tube evaporates faster or more slowly depending on the temperature. However, the heat cost allocators used nowadays are almost all electronic ones where heat consumption is measured using temperature sensors. They show the measurement readings very accurately and can also be readily used with modern low-temperature heating systems.
Furthermore, real estate service providers are continually developing the electronic heat cost allocator. For example, today ista focuses on wireless devices that can be read remotely. The big benefit for the tenant: this does away with the need for the meter reader’s annual visit. In addition, automatic readings on a fixed cut-off date increase transparency because it is easier for tenants to compare costs and consumption with the previous year.