ASHRAE JOURNAL Evolution of Automotive Heating RidingRiding inin Comfort:Comfort: PartPart II The First Century of Air Conditioning This is the ninth article in our special series to commemorate a century of innovation in the HVAC&R arts and sciences. By Mohinder S. Bhatti, Ph.D. Member ASHRAE he early automobiles at the turn of the century were like horse-drawnTT carriages except that they were powered by elec- tric batteries or gasoline-burning internal combustion engines. During the late 1800s, there were more electric cars than gaso- line cars. However, due to the gradual evolution of the internal combustion engines, popularity of the electric cars declined and their production ceased in the late 1920s. The early cars had Horseless Carriages offered no protection from the elements. only the simplest controls for operation and were aptly called horseless carriages. The driver and passengers sat on a seat Early Portable Heaters and had no protection from the elements except for special cloth- In the early years of motoring, attempts to provide comfort ing designed for motoring such as storm aprons made from heating were largely improvisations using heating aids such as heavy rubber cloth, lap robes, long fur coats, fur hats, mufflers, heated soapstone, hot brick and lantern (shown in Figure 3) that leather gloves and boots. also were used in the horse-drawn carriages. A good lap robe Figure 1 is a 1906 advertisement by the Ball-Fintze Co. of (Figure 2) in conjunction with one or more of these aids kept Newark, Ohio that shows a large five-passenger storm apron.1,2 the traveler moderately comfortable. As interest in motoring in- Figure 2 shows some of the individual motoring apparel for creased, portable coal-burning heaters appeared on the market. winter including the lap robe that appeared in the 1908 Sears, These heaters were made of galvanized iron with asbestos Roebuck & Co. catalogue and the automobile gloves that ap- lining and brass handles. They were approximately 20 in. (51 peared in a 1906 advertisement in Motor.1 It was necessary in cm) long and 7 in. (18 cm) wide and shaped like footrests as the early days of motoring to wear special driving apparel for shown in Figure 3. Some of them were covered with colored each of the four seasons. carpet that matched the carpet in the car. The coal was placed In winter, motoring was quite unreliable in the automobiles in a drawer that slid into the outer shell. The special type of early days. It was common practice to jack the car up on wooden coal used in these heaters was in the shape of a brick that burned or cinder blocks around Thanksgiving and store it until spring. without odor or smoke. Before use, the brick was placed into a As automobiles became more reliable, consideration was given brisk fire until it became thoroughly hot. It was then taken out to passenger comfort with the addition of windshields, collaps- of the fire and left standing until the flame died away. Next, the ible tops and detachable side curtains. Some electric cars used electric heating pads that were laced into the steering wheel to warm the drivers hands. Heating the About the Author Mohinder S. Bhatti, Ph.D., steering wheel for a gasoline-burning car was accomplished by a senior staff research engineer at bringing in exhaust gas by means of a flexible pipe around the Delphi Harrison Thermal Systems, Lockport, N.Y., is responsible steering wheel. Closed-body automobiles were introduced in for research relating to comfort heating and cooling systems for 1908. By 1925, production of closed-body automobiles exceeded motor vehicles. He is a member of the ASHRAE Historical that of open-body models. Attention turned to heating devices Committee and is the author of many reports and technical papers and the need to condition the air for passenger comfort. and has 28 U.S. patents. August 1999 ASHRAE Journal 51 hot brick was placed in the heater drawer. When no more heat was desired, the coal could be quenched with water and used over again. A small brick was sufficient to provide heat for several hours. Exhaust Gas Heaters Since portable heating aids required special preparation prior to motoring, at- tention turned to the on-board sources of heat for continuous heating. With this in- novation, a phalanx of heater engineers sprang into existence, mostly from the plumbing profession. Many early auto- mobile engines were air-cooled. Engine coolant as a source of heat was not uni- versally available. Accordingly, many different brands of exhaust gas heaters were put on the market, some of which were quite successful. Figure 4, taken from the 1907 advertisement in Motor, Figure 1: Storm aprons for open-body shows one such heater. automobiles.1, 2 The early exhaust gas heaters can be broadly classified as raised type and closed-body automobiles were not airtight, recessed type. The raised type were like this number was probably not too alarm- footrests that could be mounted on the ing. The exhaust gas heaters also created rear compartment floor while the recessed backpressure on the engine that under- type were mounted through the floor with mined the fuel economy and reduced the grating placed flush with the floor. power. Carbon deposit on the tube inte- These early exhaust gas heaters had no rior made frequent cleaning necessary and provision for cleaning out the dust and that required dismantling the entire heater. debris and they often leaked. They also In some cases, the heated portion of the often had an obnoxious odor. car became excessively hot, burning oc- The early exhaust gas heaters were cupants robes and leather shoe soles. mere radiators made of bundles of tubes The gradual improvements of the through which passed the exhaust gas. roads allowed cars to be used more dur- The tubes usually were covered with a ing the winter, which created demands grating of nickel-plated iron or polished for safer and higher performance heat- Figure 2a: Lap robe and muffler used in the aluminum. The control usually was a ers. One 1929 vintage heater, designed early days of motoring.1,2 valve attached to the exhaust pipe and for Model A Ford, is shown in Figure operated by a handle or lever on the floor 5.2 It consisted of an iron jacket around face. The hot exhaust gas from the engine of the car. The heaters were not engi- the manifold. The front of the heater was passed through the flue tubes around neered for a specific car or model and attached to a flexible pipe with a funnel which flowed outside air. The cold air in- required a great deal of ingenuity for in- acting as an air scoop behind the engine take consisted of a pipe with a funnel act- stallation on a specific car. Some came fan. The rear of the heater was attached ing as an air scoop behind the engine fan. with installation instructions that were to a flexible pipe running to the toeboard A unique feature was its double-header downright ridiculous. For example, instal- or floorboard where a deflector directed construction that prevented the fresh air lation of one heater called for the assis- hot air in the required direction. The de- from coming in contact with all welded tance of a ferret to crawl through the pipe flector was later replaced with a slotted joints and connections in the exhaust line. and hold two screws with its teeth! register. In summer, the register was by- The heat register was installed in the right There were numerous problems with passed by a butterfly valve and the heat dash wall in front of the front-seat pas- these rudimentary heaters. Temperature dispersed into the engine compartment. senger. The heat supply was regulated by control was difficult due to a wide varia- In 1933, Ford Motor developed a dash- a foot-operated button controlling a valve tion in the exhaust gas temperature de- mounted exhaust gas heater for Ford V-8 in the intake pipe. The heater was capable pending on the car speed. Leaks caused cars. It was built like a boiler with 24 flues, of directing the hot air to any part of the some deaths, although no statistics exist each 13 in. (33 cm) long, providing about front compartment.3 on the number of fatalities. Since the early 500 in.2 (3226 cm2) of heat radiating sur- In the mid-1930s, an unusual heater (Circle No. 32 on Reader Service Card) (Circle No. 33 on Reader Service Card) (Circle No. 34 on Reader Service Card) 52 ASHRAE Journal August 1999 HISTORY Figure 2b: Gloves and fur coats were a must for riding in early automobiles.1,2 was developed by DELCO using exhaust was why some heater engineers in the gas to generate steam. Its operation was 1940s were reluctant to abandon them in similar to the steam house heating sys- favor of the hot water heaters. tem. The system included a boiler at the muffler outlet. It was surrounded by ex- Hot Water Heaters haust gas with an average temperature of The term hot water heater refers to the 900°F (482°C). One ounce of liquid wa- heater core that derives its energy from ter was placed in the boiler. Immediately the engine coolant, which in todays au- upon starting the engine, the intense heat tomobiles is a solution comprising 50% of the exhaust converted this liquid wa- water and 50% ethylene glycol by vol- ter into steam that rose to the heater core ume.