The fans approved for use with A3 refrigerants in accordance with EN 60335-2-40 are available in various axial and centrifugal variants. Motor and fan specialist ebm‑papst offers an alternative specially designed for use in air-to-water heat pumps. For EC fan drives in size 55, 74 and 84, the electronics circuits have been modified such that they correspond to EN 60335-2-40 for heat pumps with flammable refrigerants. This means that, in the event of a fault, the maximum surface temperature must be at least 100 Kelvin below the ignition temperature of the refrigerant used. Propane, which is very well suited to new buildings and building renovations due to its good heat transfer capacity and its low GWP value, has an ignition temperature of 470 °C. The electronic assemblies, which have been tested and certified accordingly, ensure that their maximum surface temperature always remains below 370 °C, even if a fault occurs, and as a result they do not become an ignition source.
Energy efficiency and noise characteristics also play an important role when selecting fans for heat pumps. The driving force behind the fans are modern EC motors that have a high efficiency and can be controlled as required thanks to their integrated electronics. For example, if the speed at night is reduced by just 100 rpm, it is possible to reduce the noise by more than half. To reduce the noise level, the fans can usually be combined with the FlowGrid guide vanes.
The fans approved for use with A3 refrigerants in accordance with EN 60335-2-40 with maximum fill quantities of up to 1 kg or 5 kg (depending on the installation site) are available in many axial and centrifugal variants, covering the widest variety of applications for air-to-water heat pumps for outdoor and indoor use.
