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This HVAC trivia quiz has 59 free questions with answers and covers heating, ventilation and air conditioning from the Roman hypocaust and Franklin's 1742 stove to Nest thermostats and variable refrigerant flow. You will meet Willis Carrier and the Brooklyn print shop that got the first modern air conditioner, John Gorrie's 1851 ice-machine patent, Frederick McKinley Jones and Thermo King, the Frigidaire chemists behind Freon and the treaty that phased it out. The technical rounds cover the four parts of the refrigeration cycle, why a 'ton' of cooling is 12,000 BTU per hour, what SEER, AFUE and MERV actually measure, how a heat pump reverses, and which refrigerants replaced R-22. It is built for HVAC technicians and apprentices, EPA 608 candidates who want a break from the study guide, trade-school instructors, and anyone hosting a contractor team night or a facilities-management social. Easy questions ask which coil absorbs heat and where a hypocaust sent its hot air; the hard ones ask who built the first heat pump and which London hall was warmed by the Thames in 1951. Every answer has been checked against Wikipedia, the EPA, and the Carrier archive, and each question shows its citation once you have answered.
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Q 01Willis Carrier was a research engineer at which firm when he designed that first system?
Buffalo Forge
Carrier joined the Buffalo Forge Company, a Buffalo, New York maker of heaters and blowers, after graduating from Cornell in 1901; it later spun his work off as the Carrier Air Conditioning Company of America.
Q 02Who coined 'air conditioning' in a 1906 patent claim while trying to humidify his North Carolina textile mill?
Stuart W. Cramer
Stuart W. Cramer, a Charlotte, North Carolina textile engineer, wrote 'air conditioning' into a 1906 patent claim because controlled humidity keeps cotton yarn from snapping; Carrier adopted the phrase for his own company.
Q 03What was the title of Willis Carrier's U.S. patent 808,897, granted on January 2, 1906?
Apparatus for Treating Air
Patent 808,897 was titled 'Apparatus for Treating Air'; the treatment sprayed air with water to add or remove humidity, which is why early systems were essentially elaborate air washers.
Q 04How many young engineers pooled $32,600 in 1915 to found the Carrier Engineering Corporation?
Seven
The company later merged with two rivals in 1930 to become the Carrier Corporation and moved to Syracuse, New York, in 1937.
Q 05What did Willis Carrier unveil in May 1922, described as his most influential innovation?
The centrifugal chiller
The centrifugal chiller, unveiled in May 1922, replaced bulky reciprocating compressors for large jobs; its first major installation was three 195-ton units at the J.L. Hudson department store in Detroit in 1924.
Q 06In which city did Carrier's 1920s cooling system for the 2,400-seat Rivoli Theatre make headlines?
New York City
The Rivoli Theatre stood on Broadway in New York City; Carrier's 1925 installation there turned 'cool inside' summer movies into a staple of theatre marketing.
Q 07Which automaker was the first to offer an air-conditioning unit in its cars, in 1939?
Packard
Packard offered the first factory air conditioning in 1939; the unit filled much of the trunk and had no dashboard control, so switching it off meant stopping and removing the compressor belt.
Q 08In 1931 H.H. Schultz and J.Q. Sherman developed the most common type of which appliance, early models costing $10,000 to $50,000?
Room air conditioner
The room air conditioner sat on a window ledge; early units cost several times the price of a house at the time.
Q 09What was the profession of John Gorrie, who patented an ice-making machine in 1851 to cool sickrooms?
Physician
John Gorrie was a physician in Apalachicola, Florida, who chilled sickrooms for fever patients; he died broke in 1855, but Florida later placed his statue in the U.S. Capitol's National Statuary Hall.
Q 10In which country did James Harrison build his first mechanical ice machine at Geelong in 1851?
Australia
Geelong is in Victoria, Australia; Harrison, a newspaper printer there, noticed ether chilled metal type as it evaporated and scaled the effect up for breweries and meat packers.
Q 11Refrigeration pioneer Frederick McKinley Jones co-founded which company with Joseph Numero?
Thermo King
Thermo King began as the U.S. Thermo Control Company; Jones's units kept blood, medicine and food cold for army hospitals and battlefields, and he earned 61 patents in all.
Q 12In 1991 Frederick McKinley Jones posthumously became the first African American to receive which honour?
National Medal of Technology
Jones was posthumously awarded the National Medal of Technology in 1991 by President George H.W. Bush; colleagues had nicknamed him the 'King of Cool', and he entered the National Inventors Hall of Fame in 2007.
Q 13In an air conditioner, liquid refrigerant absorbs heat from indoor air as it passes through which component?
Q 21Which hydrocarbon refrigerant is used in the great majority of new European household refrigerators?
Isobutane
Isobutane, coded R-600a, is flammable, but a fridge needs so little of it, typically well under 150 grams, that the charge is comparable to a couple of cigarette lighters.
Q 22A 'ton' of cooling capacity is defined as how many BTU per hour?
12,000
One ton of cooling is 12,000 BTU per hour, or about 3.5 kilowatts; a typical house needs one to five tons, while a small window unit delivers around half a ton.
Q 23A ton of refrigeration was originally the heat to melt one short ton of ice over what period?
24 hours
The unit dates from the 1880s ice trade, giving buyers a familiar yardstick when mechanical plants began replacing harvested lake ice.
Evaporator
The evaporator coil runs cold enough for moisture in the air to condense on it, so an air conditioner also works as a dehumidifier.
Q 14Which refrigeration-cycle component is also known as the metering device?
Expansion valve
The expansion valve (or a capillary tube) is the metering device; it creates the pressure drop that lets refrigerant flash into a cold, low-pressure mist just before it enters the indoor coil.
Q 15Frigidaire, where Freon was synthesized in the late 1920s as a safer refrigerant, was then a division of which company?
General Motors
General Motors owned Frigidaire; its research team was hunting for a non-toxic, non-flammable replacement for the ammonia, sulfur dioxide and methyl chloride that made early fridges dangerous.
Q 16Which inventor did J.R. McNeill say 'had more adverse impact on the atmosphere than any other single organism'?
Thomas Midgley Jr.
Thomas Midgley Jr. led the teams behind both leaded gasoline and CFC refrigerants; at a 1924 press conference he inhaled tetraethyl lead vapour for a minute to 'prove' it was safe.
Q 17Which agreement, signed in 1987, became the first universally ratified treaty in United Nations history?
Montreal Protocol
The Montreal Protocol on ozone-depleting substances reached universal ratification in 2009; Kofi Annan called it 'perhaps the single most successful international agreement to date', and 16 September is World Ozone Day.
Q 18The 2016 Kigali Amendment to the ozone treaty phases down which class of refrigerants?
HFCs
HFCs, the hydrofluorocarbons that replaced CFCs, do not harm ozone but are potent greenhouse gases, so the Kigali Amendment repurposed the ozone treaty into a climate treaty with an 80 to 85 percent phase-down.
Q 19Which two chemists predicted in 1974 that CFCs would deplete the ozone layer?
Molina and Rowland
Mario Molina and F. Sherwood Rowland published the CFC-ozone hypothesis in Nature in 1974 and shared the 1995 Nobel Prize in Chemistry with Paul Crutzen, despite a decade of attacks from the chemical industry.
Q 20When R-22 was restricted in the 2010s, most new US home ACs shifted to which refrigerant?
R-410A
R-410A, sold under trade names such as Puron, runs at much higher pressures than R-22, so the two cannot be swapped in the same equipment; US rules from 2025 pushed new systems to R-454B and R-32.
Q 24A British thermal unit is the heat needed to raise how much water by one degree Fahrenheit?
One pound
A BTU warms one pound of water by one degree Fahrenheit, about 1,055 joules; U.S. natural gas is priced per million BTU, and home furnaces are rated in BTU per hour.
Q 25What minimum SEER rating did US federal rules set for new residential air conditioners in 2006?
13
The 2006 federal minimum was SEER 13; SEER divides a season's cooling output in BTU by the electricity used in watt-hours, and a revised SEER2 test with regional minimums took over in 2023.
Q 26In the furnace efficiency rating AFUE, what does the letter A stand for?
Annual
AFUE is Annual Fuel Utilization Efficiency: a 90 percent unit delivers 90 BTU of heat for every 100 BTU of gas it burns over a heating season, while basic furnaces sit around 80 percent.
Q 27High-efficiency condensing furnaces are vented with PVC pipe rather than metal to prevent what?
Corrosion
The acidic condensate would corrode metal flue pipe; a condensing furnace's secondary heat exchanger pulls so much heat from the exhaust that water vapour condenses out, so plastic venting prevents corrosion.
Q 28Which component makes a heat pump different from an air conditioner, letting it both heat and cool a home?
Reversing valve
The reversing valve is what lets a heat pump run in either direction; most standard units lose efficiency below about 4 °C, though newer cold-climate models keep heating down to −26 °C.
Q 29Who developed and built the first heat pump, in the 1850s?
Peter von Rittinger
Peter von Rittinger, an Austrian mining engineer, built a heat pump around 1856 to concentrate brine at the Ebensee salt works, a few years after Lord Kelvin described the principle in 1852.
Q 30Which London venue opened in 1951 with a reversible water-source heat pump fed by the River Thames?
Royal Festival Hall
The Royal Festival Hall's gas-engine-driven heat pump drew on Thames water and was a showpiece of the 1951 Festival of Britain, decades before heat pumps became a mainstream heating option.