Munters Energy Recovery Purge reduces running costs and CO2 emissions
Frederikshavn Ice Rink, Denmark, was founded in 1964 and houses Frederikshavn Hockey Club, one of Denmark's oldest ice hockey clubs, that for years has been among the best ice hockey clubs in the Danish league.
In 2002 the facilities in Frederikshavn were extended to offer more space for other ice sports. In connection to the existing area a smaller and connected arena was built for training purposes. The original arena, seating 2,800 spectators, was originally equipped with dehumidification of non-Munters brand.
Over time it became obvious that the dehumidification capacity was insufficient, as the building's timber structures were being demolished because of the high humidity and following condensation.
Dehumidification ensures improved climate
With the installation of Munters dehumidifiers IceCentre North experienced significant improvements. Condensation on the transparent protective shields did not occur any longer which was highly appreciated by spectators. There was no longer any hazing across the ice during the game, and the degradation of the building’s wooden construction stopped. Improvements to the delight of both the athletes, spectators and the arena’s maintenance staff.
In relation to a more extensive energy optimization project in 2012 Energy Project Manager Johannes Thaarup from the Municipality of Frederikshavn contacted Munters for discussion on possible energy updates of the 2 Munters dehumidifiers.
More excess heat is now recycled
Most of the excess heat generated by the compressors used for ice production in the arenas was previously exhausted to a cooling tower before it was exposed into the open as waste heat. A big share of this excess heat is now instead led to a heat exchanger and recycled. In order to make use of this waste heat for the operation of the two dehumidifiers, those got equipped with a preheater for the regeneration air.
This conversion saves approx. 2/3 of the energy that was previously used by the electric air heater for heating the air stream for regenerating the rotor.
An internal heat recovery sector, the so-called PowerPurge, was additionally built into the MXT7500. Power Purge recycles a part of the air stream from the rotor’s regeneration zone, preheating the main regeneration air stream thus reducing the need of external heat supplied.
Pay back time at only 1½ year
The estimated energy saving of the above updates grants a payback time of less than 1 ½ years and a reduction of CO2 emissions of 40 tons/year. As IsCenter North furthermore could benefit from a local public energy saving pool, the payback time was reduced to only 9 months. Already now, less than a year after the updates, the real energy savings seems to exceed the expectations. A full months extra
operation this summer was conducted without increasing the expected total energy consumption.
The energy optimization project also included an update of the central CTS system. Today the CTS system controls all key functions in the arenas, including ventilation, dehumidification, lighting, ice production, ice temperature, heating etc.
The free excess heat from the heat exchanger is first of all used to heat the domestic water, secondly for operation of the dehumidifier's preheaters and last but not least for the ventilation systems. In case of periods with insufficient amount of excess heat, the preheaters on the dehumidifiers will be run by district heating.
Savings are returned to the users
In order to increase the incentive to implement energy optimization in municipal institutions, the city of Frederikshavn recently launched an "incentive project". The project ensures that half of the money saved on energy optimization is returned directly to the specific institution and can be used according to own wishes, e.g. for a new ice machine.