GMJ phase 3 Central Heating MCQ

Which British Standard covers the method for the calculation of design heating loads?

• BS EN 12828:2003

• BS EN 12831:2003

• BS EN 14336:2004

• BS EN 1264-1:1998

What is the measurement of the U-value?

• W/m²K

• kJ/m²C

• W/kg/K

• J/m³K

What is the correct formula to determine the heat loss from a space through air changes and ventilation?

• m² x Δt x 1.33

• m² x Δt x U-value

• m³ x QTY x Δt x 0.33

• m³ x U-value x QTY x 3

What are the likely effects of oversizing a heating system?

• Reduced energy usage, as systems produce enough heat quickly before shutting off for longer periods

• Reduced life expectancy of heat emitters, which often overheat due to higher temperatures

• Greater risk of burns/scalds, due to excess temperatures within the system and increased boiler combustion efficiency

• Reduced energy efficiency, as boilers 'hunt', and greater initial outlay costs

What is the most suitable external design temperature for a house with normal sheltered exposure in England and Wales?

• -1°C

• -3°C

• -4°C

• -5°C

What is the correct formula to determine the heat loss through a surface such as a wall or window?

• m² x Δt x 1.33

• m² x Δt x U-value

• m³ x QTY x Δt x 0.33

• m³ x U-value x QTY x 3

A radiator has a temperature of 70°C at the inlet and 50°C at the outlet. What is the MWT of the radiator?

• 20°C

• 40°C

• 50°C

• 60°C

A room has an internal design temperature of 20°C. Using the answer from Question 7, determine the Delta T between the room and radiator.

• Delta T20

• Delta T40

• Delta T50

• Delta T60

You are trying to determine the correct size of an expansion vessel for a typical domestic central heating system. The system is installed in 22mm and 15mm copper. Which of the following methods could be used to give an approximate system volume?

• 2 litres per kW of the boiler

• 4 litres per kW of the boiler

• 6 litres per kW of the boiler

• 10 litres per kW of the boiler

What is the term given to the radiator within a central heating system which is the furthest from the heat source?

• The content circuit

• The shunt circuit

• The hydraulic circuit

• The index circuit