Energy and water consumption has a major role in building sustainability reports.
While energy consumption involved in heating is closely examined in the reports, the issue of air consumption in air conditioning systems only very rarely comes into focus.
The following figures show that the aims of green building and building sustainability warrant an additional focus on ventilation and air conditioning systems: About 25,000 buildings in Germany have (at least) one air conditioning or ventilation system; about 400,000 ventilation and air conditioning systems are installed; the total area of these air conditioned buildings is about 350 million square metres; the total ventilation and air conditioning costs are about € 6 billion; and the heating, cooling and flow of conditioned air generates an annual CO2 emission in Germany of about 18 million tonnes.
However, these contributions to costs and the environment are rarely examined. This is due to the fact that ventilation and air conditioning systems use other media to help them provide the desired temperatures and volume flows, resulting in ventilation consumption being lumped together with the costs for power, water and heating. For instance, air flow is produced by fans using electric power; air conditioning requires refrigeration systems that consume electric power and are monitored separately; and air is mainly heated via heating circuits, the costs of which show up in the heating budget. Ventilation costs can therefore best be described as ‘hidden costs’.
Ventilation costs are determined in buildings by taking the investment costs, maintenance costs and pro rata power, water and heating costs into account. However, this total cost is then allocated to the individual tenants according to the percentage of real estate surface they have rented. Such an allocation by area is felt by many to be unfair. On the other hand, individual tenants do not have consumption transparency and thus have no incentive to save.
Measuring technology manufacturer Halstrup-Walcher has introduced the P26, an air meter designed for installation in the air entry duct of any leased area. Similar to an electricity or water meter, the consumption values can be read directly on the air meters. The readings can also be transferred to a central metering point, enabling equitable calculation and allocation of ventilation costs commensurate with each tenant’s share of consumption.
Along with the consumption-based invoice, recording air consumption also results in an effective saving incentive; displaying consumption motivates users to conserve, resulting in savings of 20-30%.
Bestech Australia is the exclusive distributor of Halstrup-Walcher products in ANZ.