Abstract: A centrifugal fan with a pot-like impeller and with a housing, having a first circumferential wall region with an arc-like curvature which extends directly along the impeller. The housing includes in a direction of rotation of the impeller a second circumferential region with a radial distance from the impeller increasing spirally up to an outlet region. The housing includes in an opposite direction a third circumferential wall region extending to the outlet region, having an S-curvature and including a sub-region curved in the same direction as the first circumferential wall region forming a flow baffle element. Two side walls cover the axial end faces of the impeller wherein one of the side walls extends into the pot-like impeller and divides its interior into a first suction chamber having an intake and a second suction chamber. The outlet region expands in cross-section in the outlet flow direction.

Abstract: A condensation removal apparatus is disclosed. The condensation removal apparatus is used with a hot water heater wherein the hot water heater produces a fuel exhaust. The fuel exhaust from the hot water heater is provided to a draft inducer through an inlet which includes a thermally conductive plate having a hole through which the fuel exhaust flows. The draft inducer mixes ambient air with the fuel exhaust and reduces the temperature of the mixture as compared to the fuel exhaust. The mixture is directed to an outlet of the draft inducer and through piping into another environment. As the mixture cools, condensation forms within the piping. The condensation drips back down through the draft inducer. The condensation is then directed onto the thermally conductive plate. Since the thermally conductive plate maintains a high temperature, the condensation is turned from a liquid form into a gaseous form and is directed back through the draft inducer to the outlet.

Abstract: A fuel-fired low NOx water heater extending along a vertical axis has a radiant fuel burner disposed in its combustion chamber. The entire burner combustion air quantity is delivered to the burner from outside the combustion chamber via a horizontally serpentined flow path extending through an internal portion of the water heater. This serpentined air inflow path configuration causes a substantial portion of particulate matter in the incoming combustion air to be removed therefrom before entering and potentially clogging the burner.

Abstract: A water heater includes a water tank adapted to contain water; a flue extending through the water tank and having a first end communicating with the water heater's combustion chamber for the flow of products of combustion through the tank; a damper communicating with the flue; and an apparatus for creating a flow of air proximate the second end of the flue to resist the flow of warm air out of the second end of the flue due to standby convection. The apparatus for creating airflow may be a fan or an ionic wind generator. Additionally, the airflow may be directed into or across the end of the flue at the top of the water heater to either create a downdraft or an air curtain for containing warm air within the flue.