27 real HVAC & Plant Utilities questions from the Production & Plant bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is Chiller specific power?
Junior
A.kW per ton of refrigeration, about 0.6 for a centrifugal and 0.8–1.0 for a screw chiller, the key efficiency figure of a plant
B.1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
C.fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
D.kW per 100 cfm delivered, around 18–20 for a good screw compressor, with leaks often wasting 20–30% of generation
A.Chiller specific power — kW per ton of refrigeration, about 0.6 for a centrifugal and 0.8–1.0 for a screw chiller, the key efficiency figure of a plant
B.Chiller specific power — difference between outlet cold-water temperature and ambient wet-bulb, typically 3–5 °C, while range is the inlet-to-outlet water drop
C.Chiller specific power — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
D.Chiller specific power — 1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
5. Which term means: "difference between outlet cold-water temperature and ambient wet-bulb, typically 3–5 °C, while range is the inlet-to-outlet water drop"?
A.Cooling tower approach — 1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
B.Cooling tower approach — direct method compares steam output with fuel input, while the indirect method of IS 8753 sums stack, radiation and unburnt losses
C.Cooling tower approach — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
D.Cooling tower approach — difference between outlet cold-water temperature and ambient wet-bulb, typically 3–5 °C, while range is the inlet-to-outlet water drop
8. Which term means: "1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity"?
A.Indian Boiler Regulations — fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
B.Indian Boiler Regulations — kW per 100 cfm delivered, around 18–20 for a good screw compressor, with leaks often wasting 20–30% of generation
C.Indian Boiler Regulations — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
D.Indian Boiler Regulations — 1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
11. Which term means: "direct method compares steam output with fuel input, while the indirect method of IS 8753 sums stack, radiation and unburnt losses"?
A.Boiler efficiency methods — ratio of dissolved solids in cooling water to that in make-up water, run at 3–5 to save water without scaling
B.Boiler efficiency methods — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
C.Boiler efficiency methods — 1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
D.Boiler efficiency methods — direct method compares steam output with fuel input, while the indirect method of IS 8753 sums stack, radiation and unburnt losses
A.Compressed air specific power — kW per 100 cfm delivered, around 18–20 for a good screw compressor, with leaks often wasting 20–30% of generation
B.Compressed air specific power — ratio of dissolved solids in cooling water to that in make-up water, run at 3–5 to save water without scaling
C.Compressed air specific power — difference between outlet cold-water temperature and ambient wet-bulb, typically 3–5 °C, while range is the inlet-to-outlet water drop
D.Compressed air specific power — fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
A.Cycles of concentration — valve that discharges condensate while holding steam, in thermodynamic, float or thermostatic types, with failed-open traps a major steam loss
B.Cycles of concentration — kW per ton of refrigeration, about 0.6 for a centrifugal and 0.8–1.0 for a screw chiller, the key efficiency figure of a plant
C.Cycles of concentration — ratio of dissolved solids in cooling water to that in make-up water, run at 3–5 to save water without scaling
D.Cycles of concentration — direct method compares steam output with fuel input, while the indirect method of IS 8753 sums stack, radiation and unburnt losses
20. Which term means: "preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers"?
A.Energy audit — direct method compares steam output with fuel input, while the indirect method of IS 8753 sums stack, radiation and unburnt losses
B.Energy audit — fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
C.Energy audit — valve that discharges condensate while holding steam, in thermodynamic, float or thermostatic types, with failed-open traps a major steam loss
D.Energy audit — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
A.Variable frequency drive savings — kW per 100 cfm delivered, around 18–20 for a good screw compressor, with leaks often wasting 20–30% of generation
B.Variable frequency drive savings — fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
C.Variable frequency drive savings — 1950 rules under the Boilers Act 1923 requiring approved design, certified welders and annual inspection for any boiler above 22.75 litres capacity
D.Variable frequency drive savings — valve that discharges condensate while holding steam, in thermodynamic, float or thermostatic types, with failed-open traps a major steam loss
26. Which term means: "valve that discharges condensate while holding steam, in thermodynamic, float or thermostatic types, with failed-open traps a major steam loss"?
A.Steam trap — preliminary walk-through or detailed instrumented study under the Energy Conservation Act 2001, mandatory for designated consumers
B.Steam trap — difference between outlet cold-water temperature and ambient wet-bulb, typically 3–5 °C, while range is the inlet-to-outlet water drop
C.Steam trap — fan and pump power falls with the cube of speed under the affinity laws, so a 20% speed reduction cuts power by about half
D.Steam trap — valve that discharges condensate while holding steam, in thermodynamic, float or thermostatic types, with failed-open traps a major steam loss
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