Latent heat
When heat energy is added to a substance, its temperature generally rises, and when heat energy is removed, its temperature generally falls. This is referred to as ‘sensible heat’.
However, when a substance changes state, such as from a solid to a liquid, a liquid to a gas or vice versa, this change requires the addition or removal of heat energy, but does not result in a change in the temperature of the substance. This is referred to as latent heat.
There are three categories of latent heat:
- Latent heat of fusion: When a substance changes from solid to liquid (or back).
- Latent heat of vaporisation: When a substance changes from liquid to gas (or back).
- Latent heat of sublimation: When a substance changes solid to gas (or back).
Specific latent heat refers to the heat required to change the state of 1 kg of a substance without a change in temperature, expressed in joules per kilogram.
NB: This should not be confused with the term ‘specific heat’ which refers to the heat energy per unit mass required to raise the temperature of a substance by one degree Celsius.
[edit] Related articles on Designing Buildings
Featured articles and news
The UK's Modern Industrial Strategy: A 10 year plan
Previous consultation criticism, current key elements and general support with some persisting reservations.
Building Safety Regulator reforms
New roles, new staff and a new fast track service pave the way for a single construction regulator.
Architectural Technologist CPDs and Communications
CIAT CPD… and how you can do it!
Cooling centres and cool spaces
Managing extreme heat in cities by directing the public to places for heat stress relief and water sources.
Winter gardens: A brief history and warm variations
Extending the season with glass in different forms and terms.
Restoring Great Yarmouth's Winter Gardens
Transforming one of the least sustainable constructions imaginable.
Construction Skills Mission Board launch sector drive
Newly formed government and industry collaboration set strategy for recruiting an additional 100,000 construction workers a year.
New Architects Code comes into effect in September 2025
ARB Architects Code of Conduct and Practice available with ongoing consultation regarding guidance.
Welsh Skills Body (Medr) launches ambitious plan
The new skills body brings together funding and regulation of tertiary education and research for the devolved nation.
Paul Gandy FCIOB announced as next CIOB President
Former Tilbury Douglas CEO takes helm.
UK Infrastructure: A 10 Year Strategy. In brief with reactions
With the National Infrastructure and Service Transformation Authority (NISTA).
Ebenezer Howard: inventor of the garden city. Book review.
The Grenfell Tower fire, eight years on
A time to pause and reflect as Dubai tower block fire reported just before anniversary.
Airtightness Topic Guide BSRIA TG 27/2025
Explaining the basics of airtightness, what it is, why it's important, when it's required and how it's carried out.
Construction contract awards hit lowest point of 2025
Plummeting for second consecutive month, intensifying concerns for housing and infrastructure goals.
Understanding Mental Health in the Built Environment 2025
Examining the state of mental health in construction, shedding light on levels of stress, anxiety and depression.