Central Heating ppt 2

What is the purpose of determining the size of a heat emitter?

• To increase the building's temperature

• To replace lost heat and meet design temperatures

• To reduce energy consumption

• To improve air quality

What determines the output of a radiator according to the learning material?

• Size and number of convectors

• Color of the radiator

• Material of the radiator

• Brand of the radiator

How is the Mean Water Temperature (MWT) of a radiator calculated?

• Flow temp + return temp / 2

• Flow temp - return temp

• Flow temp * return temp

• Flow temp / return temp

What is Delta T50 used for in the context of radiator heat outputs?

• To show heat outputs in the UK

• To measure radiator size

• To calculate water flow rate

• To determine radiator color

What are the two main factors that the boiler heat output depends on?

• The type of fuel used and the design of the system

• The requirement of heat to the heat emitters and the requirement for hot water

• The size of the boiler and the efficiency of the system

• The cost of installation and the brand of the boiler

What is the formula for calculating heat input into a hot water storage cylinder?

• SHC x litres of water x temp. difference (Δt) x boiler efficiency / Time in seconds x 100

• SHC + litres of water + temp. difference (Δt) + boiler efficiency / Time in seconds x 100

• SHC x litres of water + temp. difference (Δt) x boiler efficiency / Time in seconds

• SHC + litres of water x temp. difference (Δt) + boiler efficiency / Time in seconds

What is the specific heat capacity of water used in the formula?

• 4.19kj/kg/°C

• 3.18kj/kg/°C

• 5.20kj/kg/°C

• 2.15kj/kg/°C

What is the usual efficiency taken for a condensing boiler in the formula?

• 93%

• 85%

• 75%

• 90%

What is the specific heat capacity (SHC) value used in the calculation for the hot water storage cylinder?

• 4.19

• 3.85

• 5.00

• 4.50

What happens to water when it is heated?

• It contracts

• It remains the same

• It expands

• It evaporates