This HVAC trivia quiz has 60 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.
30 of 60 questions with answers and explanations. Play the quiz
Q 01In 1902 Willis Carrier designed the first modern air-conditioning system for a Brooklyn firm. What did that firm do?
Print lithographs
Summer humidity was making the paper swell and the colour inks misalign, so the system was built to control moisture rather than to make anyone comfortable.
Q 02Willis Carrier was a research engineer at which firm when he designed that first system?
Buffalo Forge
Carrier had just finished a master's in engineering at Cornell in 1901; the firm's founders later backed him when he struck out on his own.
Q 03Who coined 'air conditioning' in a 1906 patent claim while trying to humidify his North Carolina textile mill?
Stuart W. Cramer
Textile mills were early adopters because the right humidity keeps yarn from snapping, and Carrier happily borrowed the phrase for his own company.
Q 04Willis Carrier was granted U.S. patent 808,897 on January 2, 1906. What was the invention titled?
Apparatus for Treating Air
The 'treatment' was spraying air with water to add or remove humidity, which is why early systems were essentially very fancy air washers.
Q 05How 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 06What did Willis Carrier unveil in May 1922, described as his most influential innovation?
The centrifugal chiller
Its first big commercial job was three 195-ton units for the J.L. Hudson department store in Detroit in 1924.
Q 07In which city did Carrier's 1920s cooling system for the 2,400-seat Rivoli Theatre make headlines?
New York City
The Rivoli had opened in 1917 under showman Samuel 'Roxy' Rothafel, and 'cool inside' summer movies became a staple of theatre marketing.
Q 08Which automaker was the first to offer an air-conditioning unit in its cars, in 1939?
Packard
The unit filled much of the trunk and had no dashboard control; to switch it off you had to stop and remove the compressor belt.
Q 09In 1931 H.H. Schultz and J.Q. Sherman developed the most common type of which appliance?
Room air conditioner
Their unit sat on a window ledge; early models cost between $10,000 and $50,000, several times the price of a house at the time.
Q 10What was the profession of John Gorrie, who patented an ice-making machine in 1851 to cool sickrooms?
Physician
He died broke and forgotten in 1855, but Florida later placed his statue in the National Statuary Hall of the U.S. Capitol.
Q 11James Harrison built the first mechanical ice machine in Geelong in 1851. Which country is Geelong in?
Australia
Harrison was a newspaper printer who noticed ether chilled metal type as it evaporated, then scaled the effect up for breweries and meat packers.
Q 12Refrigeration pioneer Frederick McKinley Jones co-founded which company with Joseph Numero?
Thermo King
During the Second World War his units kept blood, medicine and food cold for army hospitals and battlefields; he earned 61 patents in all.
Q 13In 1991 Frederick McKinley Jones posthumously became the first African American to receive which honour?
National Medal of Technology
Q 21When R-22 was restricted in the 2010s, most new US home ACs shifted to which refrigerant?
R-410A
Sold under trade names such as Puron, it runs at much higher pressures than its predecessor, so the two cannot be swapped in the same equipment; from 2025 it is itself giving way to R-454B and R-32.
Q 22Which hydrocarbon refrigerant was in over 70 percent of new EU household refrigerators by 2022?
Isobutane
Coded R-600a, it is flammable but so little is needed in a fridge that the charge is roughly a cigarette lighter's worth.
Q 23A 'ton' of cooling capacity is defined as how many BTU per hour?
12,000
That is about 3.5 kilowatts; a typical house needs one to five tons, and the unit was set as an industry standard back in 1903.
Industry colleagues had nicknamed him the 'King of Cool', and he was inducted into the National Inventors Hall of Fame in 2007.
Q 14In which refrigeration component does liquid refrigerant boil and absorb heat from indoor air?
Evaporator
Because that coil runs cold enough for moisture in the air to condense on it, an air conditioner also works as a dehumidifier.
Q 15Which refrigeration-cycle component is also known as the metering device?
Expansion valve
It creates the pressure drop that lets the refrigerant flash into a cold, low-pressure mist just before it enters the indoor coil.
Q 16Frigidaire, where Freon was synthesized in the late 1920s, was then a division of which company?
General Motors
The team was hunting for a non-toxic, non-flammable replacement for the ammonia, sulfur dioxide and methyl chloride that made early fridges dangerous.
Q 17Which inventor did J.R. McNeill say 'had more adverse impact on the atmosphere than any other single organism'?
Thomas Midgley Jr.
He also developed leaded gasoline, and in 1924 he inhaled its vapour for a minute at a press conference to prove it was safe.
Q 18Which agreement, signed in 1987, became the first universally ratified treaty in United Nations history?
Montreal Protocol
Kofi Annan called it 'perhaps the single most successful international agreement to date', and 16 September is now World Ozone Day.
Q 19The 2016 Kigali Amendment to the ozone treaty requires cutting which class of refrigerants by at least 85 percent?
HFCs
These replacements do not harm ozone but are potent greenhouse gases, so the ozone treaty was repurposed as a climate treaty.
Q 20Which two chemists predicted in 1974 that CFCs would deplete the ozone layer?
Molina and Rowland
The pair shared the 1995 Nobel Prize in Chemistry with Paul Crutzen for the work, which the chemical industry attacked for over a decade.
Q 24A 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.
Q 25A British thermal unit is the heat needed to raise how much water by one degree Fahrenheit?
One pound
It works out to about 1,055 joules, and U.S. natural gas is still priced per million BTU.
Q 26US residential air conditioners made after 2005 must have a minimum SEER rating of what?
13
The rating divides a season's cooling output in BTU by the electricity used in watt-hours; from 2023 a revised SEER2 test with regional minimums took over.
Q 27In the furnace efficiency rating AFUE, what does the letter A stand for?
Annual
A 90 percent unit delivers 90 BTU of heat for every 100 BTU of gas it burns; standard furnaces sit around 78 to 84 percent.
Q 28High-efficiency condensing furnaces are vented with PVC pipe rather than metal to prevent what?
Corrosion
A secondary heat exchanger pulls so much heat from the exhaust that water vapour condenses out, and that condensate is acidic.
Q 29Which component lets a heat pump switch between heating a home in winter and cooling it in summer?
Reversing valve
Most air-source units lose efficiency below about 4 °C, though newer cold-climate models keep heating effectively down to −26 °C.
Q 30Who developed and built the first heat pump, in the 1850s?
Peter von Rittinger
The Austrian engineer used it to concentrate brine at a salt works, only a few years after Lord Kelvin had described the theory in 1852.