Mülheim an der Ruhr, 15 March 2017 - In addition to room air exchange, the main purpose of an air handling unit is temperature control of the outdoor air volume flow at a supply air temperature that is comfortable for the user. As a rule, the required cooling duty for summer cooling of supply air is provided by a compression refrigeration system that uses fluorocarbons (FC) as refrigerant, which demonstrates direct and great global warming potential (GWP). As an alternative, natural cooling technologies based on indirect evaporative cooling often, however, fail to reach sufficient cooling capacities, and are considered only as supplements for the cooling duty provided by compression refrigeration systems.
Menerga Adconair AdiabaticzeroGWP – FC-free supply-air cooling
Menerga proves that effective cooling can take place without compression refrigeration systems. This is possible with its new carbon-neutral AdiabaticzeroGWP cooling technology, on the basis of its proven Adconair heat-recovery system. These hybrid evaporative cooling systems reliably cool hot summer outdoor air to as low as 18 °C. By combination of the technologies of indirect adiabatic evaporative cooling with dewpoint cooling – combined for the first time by Menerga in one air handling unit – it is possible to discharge high thermal loads outside the air conditioned rooms and to assure constantly low supply air temperatures.
Adconair AdiabaticzeroGWP – FC-free supply-air cooling
Menerga Adconair AdiabaticDXcarbonfree – thermally driven FC-free climate control
To prevent high power consumption during the summer cooling season, Menerga has developed its new thermally driven AdiabaticDXcarbonfree cooling technology, which is likewise based on proven Adconair heat recovery.
The cooling supply is provided by a closed adsorption refrigeration unit integrated into the air handling unit – which supplies the heating coil, used for supply air heating in winter, with cold water for cooling during the summer. Unlike a compression refrigeration system, no electric power is needed to drive this operation. Instead, heat at a temperature level beginning at 60 °C is employed – which is in any case available for heat supply during winter operation.
The recooling function of the adsorption refrigeration unit, which is integrated into the air handling system, assures very low recooling temperatures, even in high summer, and thereby enables a high energy efficiency ratio (EER). Furthermore, the water refrigerant used, R718, has a GWP of zero: which means that it has no direct carbon footprint, and that – unlike other natural refrigerants – it is neither flammable nor toxic.
Adconair AdiabaticDXcarbonfree – thermally driven FC-free climate control
With both systems, system owners and operators accordingly protect the environment by their FC-free supply air cooling, also outside the cooling season. In addition, the elimination of the coils otherwise required for refrigeration systems or coolers in the air handling unit means a reduction in fan power consumption by up to 10 % over the entire year. This benefit allows even further reduction of indirect greenhouse-gas emission by the air handling unit. From an economic standpoint as well, investment in the new carbon-free cooling technologies AdiabaticzeroGWP and AdiabaticDXcarbonfree pays off for the plant owner. Low power consumption reduces operating costs. Furthermore, elimination of maintenance of a compression refrigeration system, as well as no regular leakage testing otherwise necessary for FC-filled refrigeration systems (and stipulated in the F-Gas Regulation), reduce maintenance costs sustainably. With these new developments, rising costs for refrigerants containing FC – as a result of official quantity limitation (phase-down) for marketing of FC until the year 2035 – pose no cost risk for the later maintenance of these air handling units.