Central Heating System Design Flashcards

What is the primary purpose of a central heating system in a UK domestic property?

Answer: To distribute heat from a single source throughout the building

A central heating system distributes heat generated from a single source (usually a boiler) throughout the building via a network of pipes and radiators.

Which pipework layout uses a single pipe that connects all radiators in sequence?

Answer: One-pipe system

A one-pipe system uses a single pipe from which all radiators are connected in series; water flows through the loop and each radiator taps off it.

In a sealed central heating system, what component absorbs expansion of water when heated?

Answer: Expansion vessel

An expansion vessel contains a pressurised bladder that accommodates the increase in water volume as the system heats up, maintaining stable pressure.

What is the recommended system design working pressure for most sealed domestic central heating systems?

Answer: 1–1.5 bar when cold

Most domestic sealed systems are charged to 1–1.5 bar when cold, rising slightly when hot but remaining below the pressure relief valve set point.

Which document provides the primary design guidance for central heating installations in the UK?

Answer: BS EN 12828

BS EN 12828 is the European standard for heating systems in buildings and provides design guidance for hot water central heating systems.

What term describes the difference in temperature between flow and return pipes in a central heating system?

Answer: Delta T (ΔT)

Delta T (ΔT) is the temperature difference between the flow and return. A typical design ΔT for UK heating systems is 20°C (e.g., 80°C flow, 60°C return).