Energy advice NEA Flashcards
What is the U-value, and why is it important in the context of building insulation?
The U-value measures the rate of heat transfer through a building element (such as a wall, roof, or window). It is important because it indicates how well the building material insulates; lower U-values signify better insulation and less heat loss, contributing to improved energy efficiency in buildings
List two types of cavity wall insulation materials.
- Mineral wool fibre
- Expanded polystyrene or polyurethane beads.
What are the main categories of heating systems?
Wet central heating systems
Warm air central heating systems
Storage heating systems
Underfloor heating
Individual heaters.
Explain the function of a condensing boiler
A condensing boiler extracts more heat from the same amount of gas as non-condensing models. It has a larger surface area, often with two heat exchangers or one large one. If the products of combustion are cooled sufficiently, the water vapor in the products will condense on the surface of the heat exchanger. This condensate is collected within the boiler casing and is ejected as a slug of warm water from time to time. This process allows the boiler to be more efficient by using the latent heat of vaporization
Explain the concept of heat balance in a property.
The concept of heat balance in a property refers to the principle that energy cannot be created or destroyed, only transferred. Heat will always flow from a hot area to a cold area until both areas reach the same temperature. In a house, this means that every kilowatt-hour (kWh) of heat energy put into the house will eventually leave it. Heat enters a house from the heating system, occupants, the sun, and electrical appliances, and it leaves through various pathways such as the building fabric and ventilation. Effective insulation minimizes this heat loss, maintaining a balanced and comfortable indoor temperature
Explain the 3 ways heat moves and how each works
Radiation: Heat travels in straight lines from a hot surface to a cooler one without needing a medium, similar to how the sun’s heat reaches Earth.
Convection: Heat travels through a fluid (liquid or gas). As the fluid warms up, it rises and is replaced by cooler fluid, creating a cycle. For example, this is how radiators heat the air in a room.
Conduction: Heat travels through a solid material, transferring energy from one molecule to the next. This is how heat moves through materials like metals, bricks, or glass.
What are the four types of heat loss in a property?
Fabric heat loss: Heat escapes through the building materials.
Ventilation heat loss: Heat escapes as air blows through gaps in the building materials.
Water heat loss: Heat is lost as hot water goes down the plughole or sink.
Flue heat loss: Heat is lost up chimneys and through flues of fuel-burning appliances, affecting their efficiency
What is the purpose of a Standard Assessment Procedure (SAP)?
To assess the energy efficiency of a building
What percentage of heat is typically lost through the walls in an un-insulated semi-detached property?
35%
What is the primary benefit of using a programmable thermostat?
It automatically adjusts the temperature based on your schedule
What is the typical U-value reduction when 80mm of hot water cylinder jacket is installed?
From 6.0 to 0.5
What type of heating system involves warm air being distributed into rooms via ducts from a centrally located heating unit?
Warm air central heating
What is a common issue with older types of warm air systems?
They often produce dry air and can be noisy
What is the function of a vapour barrier in insulation?
To prevent moisture penetration and condensation
What is the typical U-value reduction achieved by insulating a pitched roof with 270mm of insulation?
From 2.1 to 0.16
