Abstract: An energy management system may include a refrigeration apparatus. Heat rejected from that apparatus may be used for heating elsewhere. There may be cooling loads which may be prone to frosting. A defrosting apparatus is provided. It is segregated from the coolant distribution array. Recaptured heat of the refrigeration apparatus may be used to defrost the cooling load heat exchangers, in an alternating or cycling mode, as may be. The apparatus may be electronically controlled. Ammonia may be used in a primary refrigeration vapour cycle system. The apparatus may also use a secondary cooling loop or system, linked to the primary system. The secondary system may be a distribution system. The secondary system may use CO2 as a heat transport medium. The coolant system may be an high pressure system, whereas the defrost system is a low pressure system. Separate circuits are provided for coolant and defrost.