An energy management system may include a refrigeration apparatus such as may
be used to form an ice rink. Heat rejected from that apparatus may be used to address
heating loads elsewhere. The apparatus may include a thermal storage apparatus,
such as may be charged with ice, or another phase change material. The refrigeration
apparatus may then be run for the purpose of obtaining the rejected heat, with
the cooling of the thermal storage material as a by-product of operation to obtain
extra rejected heat. The cold reservoir then developed in the thermal storage material
may be used subsequently to provide cooling to a different load, at a different
time of day. The thermal storage element may be used to provide cooling to a condenser
of the refrigeration apparatus, or may be placed in series with a cooling load,
such as an ice sheet or refrigerated enclosure. The apparatus may be electronically
controlled, may used ammonia as an operating fluid in a vapor cycle system. The
vapor cycle system may include a compressor, and may employ a floating head pressure
on the compressor.