Solar chimney
Solar chimneys (or thermal chimneys) are a form of passive climate management building design.
Passive climate management design maximises the use of ‘natural’ sources of heating, cooling and ventilation to create comfortable conditions inside buildings. It harness environmental conditions such as solar radiation, cool night air and air pressure differences to drive adjustments to the internal environment's climate. Passive climate management measures do not involve mechanical or electrical systems.
This is as opposed to ‘active’ climate management design, which makes use of active building services systems to create comfortable interior climate conditions, such as boilers and chillers, mechanical ventilation, electric lighting and so on. Buildings will generally include both active and passive climate management systems.
Solar chimneys are generally tall, wide structures constructed facing the sun, with a dark-coloured, matte surface designed to absorb solar radiation. As the chimney becomes hot, it heats the air inside it. The hot air rises up the chimney and is vented out of the top. As this warmed air rises, it draws more air in at the bottom of the chimney, in a process known as convection. This can be used to drive passive ventilation in buildings where cross ventilation or stack ventilation may not be sufficient, and where designers wish to avoid using energy-consuming mechanical ventilation.
Solar chimneys are particularly effective in climates that are humid and hot. They are most efficient when they are tall and wide, but not very deep, as these proportions both maximise the surface area that can absorb solar radiation and maximise the surface area in contact with the air inside the chimney.
Variations in design include incorporating multiple chambers to further increase surface area and/or using materials such as metals that have high temperature conductivity properties to maximise the temperatures achieved within the chimney. Also low emissivity coatings and glazing can also be used to reduce heat losses back to the outside, similar to the design of trombe walls.
It is important that the chimney is insulated from the building itself so that heat gains do not transmit into occupied spaces. In cooler conditions, the chimney can be used to direct absorbed heat back into the building by closing it at the top.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
A sun, tide, mass or scratch dial.
A brief description of time in the sun.
ICE Trustee Board update June 2022
Given by ICE President Ed McCann.
Artificial intelligence and project management
Two new research reports published by APM.
Association for Project Management membership offer
50% off APM Associate membership for Designing Buildings users.
Building safety, a shifting landscape for professionals
A commentary from the insurance perspective.
In brief with further links.
Walter Segal: self-built architect
A definitive book on a pioneer of green architecture.
Funding for heritage on the high street
Using heritage as a catalyst for reviving historic centres.
Commonwealth Heads of Government Meeting update.
Declaration prioritising sustainable urbanisation adopted.
A small hidden, often distant but key building component.
Some brief words about the actuator.
CIAT Chief Executive steps down.
After 34 years at the Institute.
Volunteer opportunity launched by the ICE
To support the next generation of engineers.
Provisional findings show illegal cartels in the industry.
CIAT reporting from the Competition and Markets Authority.
Making sustainable construction number one priority.
The future of construction report.
Interview with ECA CEO.
Many provisions came into force on June 28, 2022.
With room to expand.
An information packed session at the BSRIA conference.
Refurbishment, Energy Efficiency, Indoor air and process.
Create a profile, write informed product articles and share.
Aluminium Composite Panels (ACP) is one example.
We are indeed now 10 years old, so go on and be bold !
Write about something you know, help us build and grow !