NOCTI: HVAC Energy Sources and Efficiency

Calculate the energy efficiency of a gas heating system that uses 1000 kJ of energy to produce 800 kJ of useful heat.

• 70%

• 75%

• 80%

• 85%

What is the main advantage of using a gas heating system over an electric heating system?

• Lower operational cost

• Higher energy efficiency

• Easier installation

• Renewable energy source

If a gas heating system has an energy input of 1200 kJ and an output of 960 kJ, what is its efficiency?

• 75%

• 80%

• 85%

• 90%

If an electric heating system uses 1500 kJ of energy to produce 1350 kJ of useful heat, what is its efficiency?

• 85%

• 90%

• 95%

• 100%

How much energy in kW is required to produce 1000 kJ of useful heat if the gas heating system is 80% efficient?

• 2 kW

• 1.75 kW

• 1.5 kW

• 1.25 kW

What percentage of energy is lost as waste if a gas heating system has an efficiency of 85%?

• 15%

• 25%

• 10%

• 20%

If a gas heating system converts 1500 kJ of energy into 1200 kJ of useful heat, what is the system's efficiency in percentage?

• 80%

• 75%

• 90%

• 85%