New paragraphSo far, Coefficient Of Performance (COP) and Energy Efficiency Ratio (EER) have been used to compare heat pump performances in heating and cooling respectively. In particular, gas driven heat pumps performance was calculated by using the Gas Utilisation Efficiency (GUE). However, since they consider a single measuring point( rated capacity, steady indoor temperature, outdoor temperature and humidity) these parameters are scarcely reliable. The Seasonal Performance Factor (SPF) was introduced to take into account realistic operating conditions (partial loads, on-off and defrost cycles, temperature variations) during the whole season.

Each Country proposed a different calculation method for seasonal performances. Never the less, the use of average climate-model based, statistic algorithms, which take into account a wide range of temperatures with a different impact on the final value, allows a more realistic reproduction of the heat pump operation.

The GHP can be considered an integrated energy production system, rather than a simple air conditioner. In fact, reduction of building's energy need is one of the key points to achieve European targets set by the latest international agreements.

The compressors are driven by the combustion engine and thus, GHP units can operate within a wide range of outdoor temperatures without capacity loss, whereas electric heat pumps show significant lack of performance.

The latest generation of GHP has been upgraded with specifically re-designed TOYOTA engines that have very long maintenance intervals. As a result of that, reliability is enhanced while running costs are reduced, which allows the user to redirect and optimise the invested resources.

Ecology, performance and energy saving are balanced in AISIN's evolution circle, which leads to a new reference in manufacturing units with low impact on the environment.