unit 113 powerpoint 2 hot water

What are the two types of indirect hot water storage cylinders mentioned in the text?

• Double-feed and Single-feed

• Direct and Indirect

• Open and Closed

• Ventilated and Non-ventilated

Answer explanation

The text specifically mentions two types of indirect hot water storage cylinders: Double-feed and Single-feed. These terms refer to the configurations of how water is heated and stored.

Fill in the blank: An indirect system uses an indirect-type hot water storage cylinder, of which there are two distinct types: ________ and Single-feed self-venting indirect hot water storage cylinder.

• Double-feed indirect hot water storage cylinder

• Triple-feed indirect hot water storage cylinder

• Quad-feed indirect hot water storage cylinder

• Penta-feed indirect hot water storage cylinder

Answer explanation

The correct choice is 'Double-feed indirect hot water storage cylinder' as it is one of the two distinct types of indirect systems, alongside the Single-feed self-venting type.

What is a very common system of heating water?

Answer explanation

A very common system of heating water is the water heater, which uses electricity or gas to heat water for domestic use, such as bathing and cooking. It is widely used in homes and is essential for providing hot water.

What type of coil is used inside the cylinder of a double-feed indirect hot water storage system?

Answer explanation

A double-feed indirect hot water storage system typically uses a finned coil inside the cylinder. This design enhances heat transfer efficiency, allowing for effective heating of the water stored in the tank.

How does a double-feed indirect hot water storage system heat the water?

• By using a heat exchanger to transfer heat from the boiler to the water

• By directly heating the water with an electric element

• By circulating water through solar panels

• By using geothermal energy to heat the water

Answer explanation

A double-feed indirect hot water storage system heats water by using a heat exchanger, which transfers heat from the boiler to the water, ensuring efficient heating without direct contact.

Why is it called a double-feed system?

• It uses two separate feeds for operation.

• It requires double the amount of resources.

• It operates at twice the speed of a single-feed system.

• It is twice as efficient as a single-feed system.

Answer explanation

The term 'double-feed system' refers to its use of two separate feeds for operation, allowing for increased efficiency and functionality compared to a single-feed system.

What keeps the primary and secondary waters separate in a double-feed indirect hot water system?

• A single cistern

• A copper coil within the cylinder and two cisterns

• A plastic pipe

• A single valve

Answer explanation

In a double-feed indirect hot water system, the primary and secondary waters are kept separate by a copper coil within the cylinder, which allows heat transfer without mixing, and two cisterns that store each water type.

What does the cistern provide in a double-feed indirect hot water system?

• Heat

• Static head to push the water out of the outlets

• Cold water

• Electricity

Answer explanation

In a double-feed indirect hot water system, the cistern provides static head, which is the pressure needed to push the water out of the outlets. This is essential for ensuring adequate water flow to taps and fixtures.

The secondary water is heated by _________.

• conduction

• convection

• radiation

• evaporation

Answer explanation

The secondary water is heated by conduction, which involves heat transfer through direct contact between materials. In this case, the heat from the heating element is conducted to the water.

What does the cold water cistern accommodate as it heats?

• Cold water

• Expanded water

• Steam

• Air

Answer explanation

As water heats, it expands due to increased temperature. The cold water cistern accommodates this expanded water, allowing for proper pressure and volume management in the system.