A process for manufacturing a cast metal heat exchanger housing (12) for a vehicle heater having a pot-shape housing wall (14) extending in a direction of a housing longitudinal axis (L) and having a plurality of heat transfer ribs (22) extending on an outer side of the housing wall (14) in the area of a circumferential wall (16) and in the area of a bottom wall (18) of the housing wall (14) in the direction of the housing longitudinal axis (L). The process includes metal casting wherein a sprue cross-sectional area including at least some of the heat transfer ribs (22). The cast metal heat exchanger housing has an axial end face formed upon cutting off metallic material that is essentially at right angles to the housing longitudinal axis and extends into an area of at least some of the heat transfer ribs.

A furnace system features baffles, each set of baffles including one or more movable vanes, and systems for controlling the positioning of movable vanes during furnace operation. Actuators may be used to move vanes between deployed and retracted positions, the actuators controlled by units within the furnace or linked to the power sources for furnace elements which are specific to either heating or cooling operations. The movable vanes may alternately be positioned by using springs with stiffness selected to place vanes in a deployed position when under heating airflows and in a retracted position when under cooling airflows.

A fastening device for fluid tightly coupling a first duct body and a second duct body of a heat exchanger is provided. The fastening device includes a support member to couple with a connecting edge of the first duct body. The support member includes a pivot pin and a locking device disposed at an offset distance from the pivot pin along a radial axis of the fastening device. The fastening device further includes a pivot arm having a first end to engage with the pivot pin and a second end to engage with a flange of the second duct body. The locking device engages with the pivot arm and move the second end of the pivot arm relative to the pivot pin to fluid tightly engage the flange of the second duct body with the connecting edge of the first duct body.

An air handling apparatus for a HVAC system of a building. The air handling apparatus includes an enclosure having at least one inlet opening for drawing outside air into the enclosure, and at least one outlet opening for directing air from within the enclosure to outside the enclosure. At least one fan is mounted within the enclosure for drawing air through the enclosure. A burner box is centrally located within the enclosure for heating outside air drawn into the enclosure through the at least one inlet opening.

A portable indirect fuel fired heater includes a burner assembly having a fuel burner to deliver fuel from a fuel supply to a combustion chamber of the heater and a combustion air blower to deliver combustion air to the combustion chamber with the fuel for combustion in the combustion chamber to produce exhaust gases. A heat exchanger receives air to be heated in heat exchanging relationship with at least a portion of the combustion chamber. A sensor senses an oxygen level as a partial pressure of oxygen in the exhaust gases. A controller operates an actuator operatively connected to the burner assembly to controllably vary the delivery rate of combustion air and thus vary the ratio of the air and fuel responsive to the oxygen level sensed by the combustion sensor so as to maintain the sensed oxygen level at a prescribed set point level stored on the controller.

Embodiments of the present disclosure are directed to a furnace that includes a blower configured to operate to force a fluid through the furnace, a motor having a rated speed, in which the motor is coupled to and configured to actuate the blower, and a controller configured to receive data indicative of an operating characteristic of the furnace and regulate operation of the motor to be at or below an operational speed limit. The controller is configured to set the operational speed limit based on the data indicative of the operating characteristic of the furnace, such that the operational speed limit is less than or equal to the rated speed of the motor.

A furnace with a baffle assembly including at least one horizontal gap, and a heating, ventilation, and/or air conditioning (HVAC) system incorporating the same are provided. The furnace includes a furnace heat exchanger, a baffle assembly, and a fan. The baffle assembly is disposed adjacent to the furnace heat exchanger. The fan is in airflow communication with the furnace heat exchanger. The baffle assembly may include a first side and a second side. Each of the first side and the second side may respectively include a first section and a second section. A horizontal gap may be disposed between the first section and the second section (e.g., on either or both of the first side and the second side). The horizontal gap(s) may increase the efficiency of the furnace and/or the HVAC system.

An air intake apparatus configured to be operably coupled to a primary air input of a furnace so as to provide airflow into the furnace in the event the primary air input becomes blocked. The air intake apparatus includes a body having an interior volume wherein the body includes a first end and a second end. The body has openings at the first end and the second end. A first end cap member is secured to the first end and includes an intake pipe operably coupled thereto. An intake member is secured to the second end cap member and extends upward therefrom into the interior volume of the body. The body includes a plurality of apertures formed in the wall thereof operable to atmospherically couple the interior volume of the body to an atmosphere in which the air intake apparatus is present.

A heater having a burner, a first heat exchanger associated with the burner, a second heat exchanger above the first heat exchanger in fluid cooperation with the first heat exchanger and an ambient air intake blower above the second heat exchanger. The second heat exchanger comprises angularly disposed finned section so condensate within the second heat exchanger flows to a collection point and is collected in a trap. The trap includes a sensor to sense buildup of fluid in the trap with feedback to the heater controls. The heater may include a collection pan below the heat exchangers in fluid communication with the trap. In one aspect the collection pan may include a heating element to vaporize the fluid so that heated, humidified air is expelled through vents adjacent the base of the heater. In another aspect, the pan includes an ultrasonic vaporization element to vaporize fluid in the pan.

A vehicle heater includes a combustion chamber assembly unit (18) to be fed with fuel and combustion air, a housing (22) with a circumferential wall (24) defining a combustion air flow space (26), a combustion air blower (30) adjoining an end face (28) of the circumferential wall (24) of the housing (12) in the direction of a housing longitudinal axis (L), a fuel feed line and a sealing formation with a first sealing formation area arranged between the end face (28) of the circumferential wall (24) and the blower housing (32). A second sealing formation area (62) is positioned to mesh with a fuel feed line passage opening (38) for establishing a closure between the circumferential wall (24) and the fuel feed line (36). The sealing formation (56) includes a sealing element (54) providing the first sealing formation area (58) and the second sealing formation area (62).