How Victorian Brickwork Changes the Way Rooms Hold Heat in Summer and Winter.
The rooms of a Victorian house are cool. In late August, after three weeks of warm nights, the walls will be radiating heat back at you two in the morning, long after the temperature outside has dropped.
This thermal difference is often spoken of in terms of the buildings’ ‘thermal mass’, the dense clay brick of the Victorian terraces being a prime example of how a building’s walls can be designed to store up heat from the day’s sunshine to release back into the building on a cold night.
Dense clay brick of the sort used for solid walls of Victorian houses absorbs heat during the day and then releases it slowly at night. The lag between the time of day when the outside temperature is at a peak and the time of day when the inside temperature of a room is at a peak can be as much as 6-12 hours, depending on the thickness of the walls. In a south facing parlour for example it may be as late as midnight or even early in the morning before the temperature reaches its peak for the day. In a British summer when nights are generally cool this sort of thermal mass is very beneficial. The walls of the house charge up with heat during the day and then release it harmlessly into the cool night air the following day. Historic England’s technical guidance on how thermal mass affects heat loss in historic buildings for example provides a detailed explanation of how this sort of solid brick construction works as thermal mass.
As nights stay warm, the wall never gets to fully discharge and the following day’s heat loads are added to those of the previous day. Soon the brick is storing heat rather than acting as a buffer and it is slow to warm up but also slow to cool down.
When designing air cooling systems for Victorian properties in Gloucester the approach is generally different to newer buildings of a similar size, because Victorian rooms have a higher thermal mass than modern dwellings. Thus a system sized for a building of similar floor area made up of Insulated Block/Panel Walls will be undersized for a comparable area of a Victorian property, three weeks into the long hot summer. The positioning of the air cooler within a room is also important; by positioning it so that it blows air across the internal face of the walls it can draw out the stored heat more effectively than a cooler positioned in the centre of the room blowing air straight up to the ceiling. If you want Air conditioning Gloucester, https://acecc.co.uk/ is a good place to start.