Hot Water Systems Objectives

Explain the differences between indirect and direct storage systems in hot water systems used in dwellings.

• Indirect systems use a heat exchanger, while direct systems heat water directly.

• Direct systems are more energy-efficient than indirect systems.

• Indirect systems are cheaper to install than direct systems.

• Direct systems require less maintenance than indirect systems.

Which of the following is a feature of unvented hot water systems?

• They require a vent pipe.

• They are directly connected to the mains water supply.

• They use a gravity-fed system.

• They cannot be used with solar panels.

What are the two main categories of hot water systems shown in the diagram?

• Electric and Gas

• Solar and Heat Pump

• Instantaneous and Storage

• Boiler and Tankless

Centralised open-vented systems can be further sub-divided into: the direct system, the indirect system, _________?

• the semi-direct system

• the closed system

• the hybrid system

• the gravity system

Centralised open-vented systems can be further sub-divided into: the direct system, the indirect system, the double-feed indirect system, _________.

• the single-feed indirect system

• the closed-loop system

• the dual-feed direct system

• the open-loop direct system

What type of hot water storage system uses a direct type hot water storage cylinder?

• Open vented system

• Unvented system

• Combination boiler system

• Solar thermal system

Which type of indirect hot water storage cylinder is also known as primatic?

• Double-feed

• Single-feed

Where should the cylinder control thermostat be positioned in an indirect hot water supply system?

• Between ¼ and ⅓ from the base of the cylinder.

• At the very top of the cylinder.

• At the bottom of the cylinder.

• In the middle of the cylinder.

An unvented hot water storage system is:

• A system that uses a vent to release pressure

• A system that stores hot water without a vent

• A system that requires a constant water supply

• A system that uses solar energy to heat water

The purpose of the mechanical safety devices in the unvented hot water system is to:

• Prevent overheating and overpressure

• Increase water flow

• Reduce energy consumption

• Enhance water quality