Experimental information on heat transfer is necessary to calculate coils and equipment using them. The requirements for measurement accuracy as well as for that of measuring instruments are stated for coils and air conditioners to be thermotechnically tested. A device of the calorimetric complex “IEMZ Cupol” is described in the paper for studying heat transfer in coils to heat and cool air, as well as for testing heating and cooling capacities of conditioners. The scope of using the complex to simulate conditions on the sides of air, hot and cold water, boiling and condensed coolants R22 and R134a is described.