Furnaces Then and Now
According to Wikipedia, a furnace is a device used for heating. In American English and Canadian English, the term furnace on its own is generally used to describe household heating systems based on a central furnace known either as a boiler or a heater in British English, and sometimes as a synonym for a kiln, a device used in the production of ceramics. In British English, the term furnace is used exclusively to mean industrial furnaces.
To go back a little in history, central heating with a furnace is an idea that is centuries old. This idea was invented by the Romans and called a hypocaust. It was a form of under-floor heating using a fire in one corner of a basement with the exhaust vented through flues in the walls to chimneys. This form of heating could only be used in stone or brick homes. It was also very dangerous because of the possibility of fire and suffocation.
Early furnaces burned wood. In the seventeenth century, coal began to replace wood as a primary fuel. Coal was used until the early 1940s when gas became the primary fuel.In the 1970s, electric furnaces started to replace gas furnaces because of the energy crisis. Wood and coal burning furnaces required constant feeding to maintain warmth in the home. From early morning to late at night, usually three to five times a day, fuel needed to be put in the furnace. In addition, the waste from the ashes from the burnt wood or coal had to be removed and disposed of. Today, the gas furnace is still the most popular form of home heating equipment. Your Virginia Beach HVAC specialist can share with you a wealth of knowledge about today’s gas furnaces and which would be best suited to your Virginia Beach home.
Raw materials – design of original fireplaces
Today, stainless steel is used in the heat exchangers for corrosion resistance. Aluminized steel is used to construct the frame, blowers, and burners, and brass is used for valves, copper in the electrical wiring, and fiberglass to insulate the cabinet. Today’s gas furnace consists of a heat exchanger, secondary heat exchanger (depending on efficiency rating), air circulation blower, flue draft blower, gas control valve, burners, pilot light or spark ignition, electronic control circuitry, and an external thermostat. The modern furnace is highly efficient-80-90%, allowing only 10-20% of the heated air to escape up the chimney.
The manufacturing process today
The primary heat exchanger is formed from two separate pieces of 409 stainless steel sheet. Each half is formed into shape by a 400 ton hydraulic press.
• The secondary heat exchanger is formed from 29-4°C stainless steel tubing and fins. The fins are welded to the tubing to form a radiator type configuration.
• The primary heat exchanger is crimped to the secondary heat exchanger through a transition box. The flue draft blower is attached to the secondary heat exchanger.
• The cabinet consists of two doors and the cabinet housing.
• The cabinet is installed around the furnace assembly and secured with screws and nuts.
• The doors are installed on the front of the cabinet assembly. The completed assembly is boxed and prepared for shipment.
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