What is the maximum heat output covered by the unit for central heating systems?

• 20kW

• 30kW

• 40kW

• 50kW

Answer explanation

The correct choice is 40kW, which is the maximum heat output covered by the unit for central heating systems.

What is the diameter of the pipework covered by the unit for central heating systems?

• Up to 16mm

• Up to 24mm

• Up to 32mm

• Up to 40mm

Answer explanation

The correct diameter of the pipework covered by the unit for central heating systems is up to 32mm.

What do modern central heating systems use to provide the best possible heating?

• Traditional boilers

• Energy saving appliances and boilers

• Manual controls

• Basic components

Answer explanation

Modern central heating systems use energy-saving appliances and boilers to provide the best possible heating, ensuring efficiency and cost-effectiveness.

What percentage of heat from a radiator is convected heat?

• 20%

• 50%

• 80%

• 100%

Answer explanation

80% of the heat from a radiator is convected heat, making it the correct choice.

At what temperature does the radiator operate in the diagram?

• 18°C

• 21°C

• 24°C

• 70°C

Answer explanation

The radiator operates at 70°C as indicated in the diagram.

What happens to the hot air in a radiator heating system?

• It descends

• It rises

• It stays at the same level

• It cools down immediately

Answer explanation

In a radiator heating system, hot air rises due to convection, creating a cycle of warm air circulating and heating the room.

What is the temperature of the cooler air as it descends in the diagram?

• 18°C

• 21°C

• 24°C

• 70°C

Answer explanation

The temperature of the cooler air as it descends in the diagram is 21°C, which is the correct answer choice provided.

What is the primary purpose of central heating in dwellings?

• To provide heat and warmth

• To create a thermally comfortable environment

• To reduce energy consumption

• To improve air quality

Answer explanation

The primary purpose of central heating in dwellings is to create a thermally comfortable environment.

What is the ideal humidity range for humans to feel comfortable?

• 20-30%

• 30-40%

• 40-60%

• 60-80%

Answer explanation

The ideal humidity range for humans to feel comfortable is 40-60%, as it helps prevent dry skin, respiratory issues, and static electricity buildup.

What happens if the humidity level is below 40%?

• The atmosphere becomes damp and clammy

• The eyes and throat become dry

• The body sweats excessively

• The body craves water

Answer explanation

The eyes and throat become dry