Exhaust air heat pump
Contents |
[edit] Introduction
Exhaust air heat pumps collect warm air as it leaves a building via the ventilation system and then reuse the heat that would otherwise be lost to the outside to heat fresh air coming into the building or to heat water. Exhaust air heat pumps operate on a similar basis to other heat pumps such as air source heat pumps and ground source heat pumps and are suitable for providing hot water and heating for buildings such as houses, apartments or flats. Exhaust air heat pumps are often used in conjunction with underfloor heating systems and have been used extensively in countries such as Germany and Sweden.
[edit] Components and system
The typical basic components of an exhaust air heat pump comprise a hot water cylinder, heating coil, extractor fan and a heat pump.
The system works by extracting air through a series of ventilation ducts from moisture-producing rooms such as bathrooms, utility rooms and kitchens. The heat energy in the air is passed over a heat exchanger which then transfers the energy to a refrigerant. The refrigerant boils and evaporates and as a gas, it is then compressed. As the compression takes place, heat is released which is then transferred to the hot water supply, or to the hot water heating system, or to incoming air which supplies non-moisture producing spaces such as bedrooms and living rooms.
As a series of ducts are required through the building to allow the flow of air to and from the exhaust air heat pump, installation tends to happen during the original construction of buildings. Retrofitting into existing buildings may not be practical or cost-effective.
[edit] Benefits of exhaust air heat pumps
The main benefits of using exhaust air heat pumps include:
- Reduction in the cost of fuel bills.
- Reduction in the environmental impact of buildings through a reduction in CO2 emissions.
- Contribution to compliance with building regulation requirements.
- Continuous ventilation of building which can help improve indoor air quality and prevent condensation.
[edit] Disadvantages exhaust air heat pumps
There are some disadvantages to exhaust air heat pump systems including:
- Installation costs can be high.
- Retrofitting can be disruptive and expensive.
- They work most efficiently with underfloor heating systems since they typically heat the water to lower temperatures than traditional radiator systems. Although radiators can work at lower temperatures, they will take longer to heat up rooms.
- It may not possible to rely on exhaust air heat pump systems in isolation for all heating needs and so a secondary system may be required.
- Heat pump efficiency can be significantly compromised by incorrect specification, poor installation, incorrect commissioning and incorrect operation. See Residential heat pump installations: the role of vocational education and training.
A recent government study is available which considers the efficiency of exhaust air heat pumps installed in social housing based on investigations carried out between 2010 and 2013. Ref DECC, Performance of exhaust air source heat pumps: Summary of detailed monitoring results.
[edit] Related articles on Designing Buildings Wiki.
- Absorption heat pump.
- Air source heat pumps.
- BSRIA global heat pump market 2019.
- Coefficient of Performance CoP.
- Domestic heat pumps and the electricity supply system.
- Dynamic thermal modelling of closed loop geothermal heat pump systems.
- Earth-to-air heat exchangers.
- Ground source heat pumps.
- Heat exchanger.
- Heat pump.
- Renewable energy sources: how they work and what they deliver: Part 3: Electrically driven heat pumps DG 532 3.
- Residential heat pump installations: the role of vocational education and training.
- Room-based heat pumps.
- Water source heat pumps.
[edit] External references
Featured articles and news
Amendment to the GB Energy Bill welcomed by ECA
Move prevents nationally-owned energy company from investing in solar panels produced by modern slavery.
Gregor Harvie argues that AI is state-sanctioned theft of IP.
Heat pumps, vehicle chargers and heating appliances must be sold with smart functionality.
Experimental AI housing target help for councils
Experimental AI could help councils meet housing targets by digitising records.
New-style degrees set for reformed ARB accreditation
Following the ARB Tomorrow's Architects competency outcomes for Architects.
BSRIA Occupant Wellbeing survey BOW
Occupant satisfaction and wellbeing tool inc. physical environment, indoor facilities, functionality and accessibility.
Preserving, waterproofing and decorating buildings.
Many resources for visitors aswell as new features for members.
Using technology to empower communities
The Community data platform; capturing the DNA of a place and fostering participation, for better design.
Heat pump and wind turbine sound calculations for PDRs
MCS publish updated sound calculation standards for permitted development installations.
Homes England creates largest housing-led site in the North
Successful, 34 hectare land acquisition with the residential allocation now completed.
Scottish apprenticeship training proposals
General support although better accountability and transparency is sought.
The history of building regulations
A story of belated action in response to crisis.
Moisture, fire safety and emerging trends in living walls
How wet is your wall?
Current policy explained and newly published consultation by the UK and Welsh Governments.
British architecture 1919–39. Book review.
Conservation of listed prefabs in Moseley.
Energy industry calls for urgent reform.