A new control algorithm for future use in an ECC (Electronic Climate Controller) has been developed. To overcome the problem of having many controller inputs and outputs, we used a method of breaking down the problem to a one dimensional one; the method was named the quantifier-selector method. As the name suggests it consists of a quantifier part and a selector part; the quantifier calculates ‘how much’ heating or cooling is needed; the result from the quantifier is used in the selector when deciding ‘how’ to achieve this cooling/heating. The quantifier consists primarily of a rather unconventional nonlinear PI controller and some feedforward compensations. The selector is mainly made up of static mappings.The algorithm was tuned using simulations and rapid prototyping techniques in a climatic wind tunnel and during road tests.The performance of the system has been satisfactory and also a significant energy saving could be verified.