Environmental Engineering Reference
In-Depth Information
requirements during these periods. The heat pump should also have additional
capacity to produce surpluses for these times. The special tariff is often one-third
less than the standard tariff. If a special tariff can be applied to the heat pump, the
fuel costs for the pump will normally be considerably lower than for natural gas or
oil heating. Users who want to use climate-compatible green energy to run a heat
pump will usually not benefi t from any special tariffs.
Whether a heat pump pays for itself in the long term depends mainly on the devel-
opment of gas, oil and energy prices. Biomass heating shows evidence of low fuel
prices and is another alternative to oil and natural gas heating.
www.heatpumpcentre.org
IEA Heat Pump Centre
www.ehpa.org
European Heat Pump Association
11.5 Ecology
Heat pumps are generally regarded as a positive use of the environment. But this is
not always the case. The Achilles heel of heat pumps is the refrigerant. The range
of refrigerants for compression heat pumps is broad. Chlorofl uorocarbon s ( CFC )
were often used during the fi rst heat pump boom. Because of their negative impact
on the ozone layer, their use has been banned in new systems.
Today hydrofl uorocarbons (HFC), often called CFC equivalent substitutes, are
mostly used. Although they are harmless to the ozone layer, they share another
characteristic with CFC that is negative for the environment: both materials have
extremely high greenhouse potential. As a result, even small quantities of between
1 and 3 kg of refrigerant in heat pumps for single-family homes are developing into
an ecological problem.
If 2 kg of HFC R404A reaches the atmosphere, it develops the same effect on the
climate there as 6.5 tons of carbon dioxide. This quantity of carbon dioxide is
emitted during the burning of 32 500 kilowatt hours of natural gas. The same amount
heats a standard new-build house for three years, and a three-litre house for no fewer
than nine years. The energy needs of the heat pump itself are not even included in
this balance sheet.
If a leakage occurs in a heat pump system, the refrigerants escape quickly because
they evaporate under normal environmental conditions. On the positive side, HFC
substances are neither toxic nor infl ammable. However, in terms of climate-
compatibility, the fast volatility of refrigerants turns out to be a problem. Not every
heat pump will develop a problem whereby its entire content of refrigerant escapes
into the atmosphere. However, refrigerant loss is unavoidable during the fi lling
and disposal of a system and, due to continuous seepage, during regular operation.
Nowadays standard heat pump suppliers seldom use refrigerants that can adversely
affect the climate. At the same time heat pumps with R290 or propane as the
 
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