Tempering heating is a form of convection heating that is installed either into - or adjacent to - walls to moderate the temperature and moisture levels inside. This type of radiant heat distribution was introduced in 1982 by the Bavarian State conservation office.
As a form of climate control, tempering heating developed as a method for managing rising damp problems in museums where the moisture and its related consequences (such as mould, salt, bacteria and so on) could damage artwork and other vulnerable items in museum collections.
A tempered heating system generates a steady flow of warm air that travels through a collection of looping tubes in the shell of the building. This approach reduces the capillary distribution of all forms of dampness while heating the room at the same time.
This type of radiant heating system warms surfaces that then in turn re-radiate heat and warm air adjacent to them by convection. This allows heat from a radiant source to distribute through a space. Because it is mainly directly heating through radiation, rather than heating the air (as in convective heating), it can be more efficient, particularly in large spaces, in spaces with poor insulation or in unenclosed or semi-enclosed spaces.
A tempered wall radiant heating system tends to be a low-temperature system spread over large surface areas. It heats certain walls continuously throughout the year, while others are only heated when colder temperatures are expected.
 Benefits and drawbacks
- More healthy, separating heating from ventilation, and so reducing problems associated with dust, pollen and other pollutants.
- More durable.
- More comfortable, giving a more even temperature distribution.
- Space saving and unobtrusive.
- Less expensive to run in certain situations. Low temperature systems in particular can run at a lower overall temperature than conventional heating systems whilst still achieving comfortable conditions.
- Easier to maintain.
- More directed.
- High temperature electric radiant heaters can be expensive to run.
- It can impose restrictions on floor and wall coverings.
- It can be expensive to instal.
- It can be less effective at cooling, and there can be condensation issues.
- There can be poor familiarity amongst designers and installers.
- It can be difficult to retrofit.
- It can be difficult to repair.
 Related articles on Designing Buildings Wiki
- Air handling unit.
- Building services.
- Capillary action.
- Defects in stonework.
- Heat pump.
- Heat recovery.
- Heat stress.
- Heat transfer.
- Radiant heating.
- Retrofit and traditional approaches to comfort.
- Rising damp.
- Thermal comfort.
 External references
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