Abstract: An apparatus for measuring the surface pore size in an externally enhanced evaporator tube. Basically, the apparatus includes a pressure housing and gage that are sealingly engagable around a portion of the surface of the enhanced tube, so that fluid pressure flows into the housing and then through the pores and subsurface channels on the tube and then to the outside of the housing. The pressure drop across the pores and subsurface channels of the tube relates to the size of the pores.

Abstract: An apparatus and method for use in a combustion system of a gas-fired furnace to inhibit formation of oxides of nitrogen (NO.sub.x) by the combustion system thereby reducing NO.sub.x emissions from the combustion system. The apparatus is made of a material which is positioned at the interface of the primary zone and the secondary zone of a combustion flame produced by a two-zone burner which is part of the combustion system, to temper the combustion flame by absorbing thermal energy from the combustion flame. The device sufficiently tempers the combustion flame to limit peak combustion flame temperatures and residence times at these peak combustion flame temperatures to levels which inhibit formation of oxides of nitrogen.

Abstract: A method and control system for manufacturing externally enhanced evaporator tubes. A pressure signal indicative of the pore size on the external surface of the enhanced evaporator tube is provided to a microcomputer system which processes the signal indicative of the pore size and compares the signal to a predetermined pore size signal to determine when the pore size is within a selected tolerance. The microcomputer generates a control signal to adjust the enhancing process if the microcomputer system determines that the pore size of the manufactured tube is different than the selected pore size.

Abstract: A porous coated enhanced evaporator tube and a method for producing the tube. The porous coating of the tube is applied by arc spraying two dissimilar metals on a tube and then etching the tube so that only one of the metals is etched out, and a porous surface, having voids where the etched out metal is developed. The voids form subsurface channels which provide nucleate boiling sites.

Abstract: A method and control system are disclosed for operating an integrated heating system for space heating and tankless domestic hot water heating utilizing an infrared burner module and heat exchanger coil. When the system is below 100% capacity, the burner is pulsed using a constant pulse period and varying the on-pulse width to vary capacity, or where a minimum on-pulse width is maintained the off-pulse width is varied to vary capacity.

Abstract: A noise attenuating assembly for use in conjuction with an air conditioning unit having a sloped discharge opening is disclosed. The assembly includes a front wall and a pair of side walls forming a flow path for the conditioned air which is discharged to the space containing the unit. The assembly has a layer of sound attenuating material attached to the inside surface of the walls so that the assembly deflects and absorbs line-of-sight sound produced by the unit fan, thus reducing the noise level of the unit.

Abstract: A method and apparatus for expanding copper and aluminum tubes in either compression expansion or tension expansion which is adjustable to expand different configurations of coils on row at a time.

Abstract: A method of closely controlling the supply air temperature delivered from an air conditioning unit into a mobile cargo container wherein the supply air temperature is compared to a desired set point temperature and a suction control valve in the air conditioner compressor inlet line is adjusted in response to the sensed difference between the supply air temperature and the set point temperature. Three different preprogramed control modes are available which are selected automatically in response to the amount of deviation between the compared temperatures that are used to bring the supply temperature down the set point temperature and hold it under steady state conditions within .+-.0.25.degree. C. of the set point. A trim heater is placed in the supply air passage to warm the supply air any time the control valve is in a full closed position. This increases the heating load on the unit so that operating time of the unit will be prolonged and the compressor will not be cycling ON and OFF.

Abstract: A sine-wave like plate fin for a finned tube heat exchanger coil is provided having an improved enhanced heat transfer area between adjacent pairs of holes in the plate fin. The enhanced heat transfer area includes a plurality of raised lance elements disposed thereon generally at the peaks and troughs of the sine-wave wherein the raised elements at the peaks are concave and the raise elements at the troughs are convex.

Abstract: A method for tension expanding a plate fin heat exchanger to provide a heat exchanger with bells of the same form and dimension and then expanding the tube into contact with the tube sheets and hairpin tubes while the bells are clamped to prevent the hairpin tubes from moving.

Abstract: A gas-fired condensing furnace with a corrosion resistant condensing heat exchanger. The condensing heat exchanger is formed from a flat sheet of engineering metal with a layer of polypropylene sheet material laminated thereto. Each condensing heat exchanger has a condensing flow passage of serpentine shape formed in the laminated flat sheet of engineering metal such that the polypropylene layer will be exposed to the flue gas/condensate environment to provide corrosion resistance to the metal.

Abstract: An outdoor coil temperature detection scheme in a heat pump system effective for developing outdoor ambient temperature indications from outdoor coil temperature data, for use in heat pump control.

Abstract: A sine-wave like plate fin for a finned tube heat exchanger coil is provided having an improved enhanced heat transfer area between adjacent pairs of holes in the plate fin. The enhanced heat transfer area includes a plurality of rows of triangular ramp wings which generate counter rotating vortices to promote restarting or thinning of the hydrodynamic boundary layer.

Abstract: A method and apparatus for belling and expanding the tubes of a plate fin heat exchanger that involves a gripper for gripping the tube during the belling operation and a clamp for clamping a tube sheet during the tension expanding operation.

Abstract: A gas-fired condensing furnace with a corrosion resistant condensing heat exchanger. The condensing heat exchanger is formed from a perforated flat sheet of engineering metal with a layer of polymer sheet material laminated thereto. Each condensing heat exchanger has a condensing flow passage of serpentine shape formed in the laminated flat perforated sheet of engineering metal such that the polymer layer is permeated by water condensed from the flue gases, and the permeated water flows through the perforated sheet metal and is not allowed to accumulate at the interface between the engineering metal and the polymer sheet.

Abstract: A sine-wave like plate fin for a finned tube heat exchanger coil is provided having an improved enhanced heat transfer area between adjacent pairs of holes in the plate fin. The enhanced heat transfer area includes a plurality of rows of triangular delta wings and ramp wings which generate counter rotating vortices to promote restarting or thinning of the hydrodynamic boundary layer and mixing the bulk fluid.