Temperature is measured using PT100 platinum resistance temperature detectors to DIN 43760 class A with an accuracy of ± 0.15°C (T in Figure 1). Humidity is measured using capacitive humidity sensors, complete with sensor mounted transmitter electronics (RH in Figure 1). Two different models are

being used with a low-temperature accuracy (0-40 °С) of ± 1.5%RH and a high-temperature accuracy (40-90 °C) of ± 1.3-3%RH. Velocity is measured by a hot wire anemometer with an accuracy of ±

0.032 m/s per °С difference to 25 °С (V in Figure 1). The pressure loss over the wheel is calculated using differential pressure sensors with an accuracy of ± 12.5 Pa (DP in Figure 1).

2.1 Material data

The desiccant wheel under investigation in this work is coated with a Ferro-alumino-phosphate zeolite with an iron content of 5 mol%, named “Functional Adsorbent Material Zeolite 01” by the manufacturer and traded as FAM-Z01. The wheel investigated has a diameter of 300mm and a depth of 200mm. Material isotherms for the FAM material are shown in Figure 3. More details on the material itself are given by Kakiuchi [6].

It can be seen in Figure 3 that the adsorption capacity of FAM-Z01 is low in the low relative pressure range but increases drastically at higher relative pressures. A large amount of water can be adsorbed in a rather narrow range of relative pressures. Increasing equilibrium temperatures cause this pressure range to extend further. Figure 3 also shows the desorption equilibrium isotherm for 60 and 75°C regeneration temperature. It can be seen that there is only a small difference in the amount of water ad — /desorbed for ad — and desorption, respectively.