Space and Water Heating Systems

Space heating is the process utilized to warm an enclosed area within premises.
- Contrast with Central Heating: Central heating warms multiple connected spaces simultaneously from a single heating source.

Convection Heaters
- Mechanism: Heating elements warm air directly or heat an oil or filler that transfers heat to the air.
- Process: Warm air rises into the room, promoting convection currents that circulate and increase the overall room temperature over time.
- Recommended Use: Ideal for well-insulated rooms, providing constant, diffuse heat.
Oil Heaters
- Characteristics: Heat up slowly, do not reach hazardous surface temperatures.
Wire-Element Heaters
- Characteristics: Can be fan-assisted; reach operational temperatures quickly but may pose fire hazards.

Construction: Comprise tungsten filaments situated in heat-resistant quartz envelopes, placed in front of a metal reflector, housed in either plastic or metal casings.
Operating Principle: Radiate energy primarily in the infrared spectrum and function similarly to light bulbs.
Efficiency: Convert up to 86% of their input power into radiant energy, losing the remainder to conductive and convective heat.

Radiation from these heaters is absorbed directly by clothing and skin without requiring prior heating of the surrounding air.
Suitable for:
- Poorly insulated rooms.
- Outdoor environments.

Small electrical convector and radiant heaters can connect via:
- Flexible Cord: Plugged into a socket outlet.
Fixed small heaters can be permanently wired to a socket using a switched/fused connection unit with a flex outlet.
Larger Heating Appliances: Such as electric storage heaters require:
- A separate circuit for each heater returning to its protective device.
- Installation of a flex outlet adjacent to the heater for final connections.

Flex Type: Must be heat-resistant flexible cable to withstand high temperatures involved in heating.

Description: Systems can be installed beneath various flooring types, including stone, tile, wood, or carpet. Helps maintain warmth in cold floors and rooms.
Installation Types: Include:
- Loose-fit wiring, flexible for small or irregular spaces.
- Electric cable systems or heating mats that cover larger areas.
Compatibility with Carpeted Rooms: Can be installed in carpets as long as the carpet density allows heat to rise.
Installation Layers: Electric heating sheets or cables are situated beneath the flooring and are usually installed on top of:
- A flat layer of screed.
- A layer of floor insulation to optimize heat distribution upwards.

Cold Tail: The part of the heating mat or cable that remains cool.
- Purpose: Connects to the thermostat or junction box.
- Construction Components: Comprising three elements:
- Line (brown).
- Neutral (blue).
- CPC (yellow and green), typically enclosed in a black sheath.
Temperature Control: A sensor is integrated into the flooring and connected to a thermostat, often containing a time clock for pre-scheduling heating operations.

Mechanism: Use heat-retaining clay bricks charged overnight by a heating element, which stores heat to release during the day.
Heating Method: Utilize both convection and radiation for a balanced heating output in the room.
Energy Tariff: Designed to use Economy 7 electricity at night, which is advantageous for lowering heating expenses.

Common Form: Immersion heater installed within a hot water cylinder.
- Construction: Features resistance wire that generates heat when current flows, thereby heating the water.
- Thermostat: Automatically disconnects supply when the water reaches an optimal temperature usually set at 55–60°C, balancing safety against scalding and the risk of legionella bacteria development.
- Regulatory Requirement: BS 7671 Regulation 554.2.1 mandates measures to prevent dangerous temperature rises.

Connection Specifications: Must be fed from an independent circuit connected to a switched/fused connection unit located adjacent to the water cylinder, using heat-resistant flexible cable.

Description: High-power devices that heat water instantly as it flows through, without internal water storage apart from what's in the heat exchanger coil.
Common Examples: Include instantaneous showers and point-of-use (POU) water heaters supplying hot water for sinks or basins.
Operation of Electric Showers: When activated, water flows through the heater chamber and is rapidly heated by the high-powered element, then directed to the hot water outlet.
Temperature Regulation: Controlled by flow rate:
- Slower flow rates provide hotter water.
- Faster flow rates yield cooler water.
Electrical Requirements: The shower unit operates off its own circuit in the consumer control unit, with a double-pole switch installed near the shower unit for safety.