A valve component may include a polyurethane coating electrocoated thereon. The economizer heat exchanger has a first pass for receiving a first portion of the refrigerant having traversed he refrigerant-to-liquid heat exchanger and a second pass for receiving a second portion of the refrigerant having traversed the refrigerant-to-liquid heat exchanger. Another embodiment includes a handheld shower assembly including at least two pieces. Also, an infra-red beam smoke detection apparatus comprises a base unit having an internal electrical wiring terminal arrangement for connection to an external electrical cable for power supply and data transfer; connectable by bayonet coupling to a head unit containing optical components and electronic circuitry and an electrical terminal arrangement connected to the electronic circuitry.