Abstract: A unit for use in a diving bell to heat and remove carbon dioxide from the breathing gas in the bell. A blower circulates the atmosphere in the diving bell through a heat exchanger, which is heated by hot water from an installation on the surface. Part of the air is vented back into the bell atmosphere and part is passed through a scrubbing canister containing material which removes carbon dioxide from the gas. The unit is very compact and the scrubbing canister is readily replaceable for servicing. In the hot water system, provision is made for controlling the flow and for delivering hot water to divers having heated suits.

Abstract: A diver's gas heater, for use with a hot water heated suit, to heat the diver's breathing gas for added comfort in cold water. Hot water from a surface installed source is pumped through a hose to the diver's suit and the heater is installed directly in the hot water supply hose. The hot water passes through a tubular heat exchanger and the breathing gas flows through an annulus around the water conducting tube. A portion of the hot water is tapped off to maintain heating around the short length of breathing gas hose between the heat exchanger and the diver's helmet.