Ventilation#
People and their activities give off moisture. Ventilation is required to remove moisture and stale air from the building. This also removes heat.
The traditional approach to ventilation is to provide features that allow users to introduce fresh air as needed - throwing up bathroom and kitchen windows, for instance. Over the years, ventilation features that are less “all-or-nothing” have appeared. Trickle vents in windows are a good example. The idea is still that users will exercise their judgment to get the airflow right and remember to close the vents when they are no longer needed. Some community building users are good at this but others aren’t.
Victorian buildings, especially churches, can have very generous ventilation features that cause a great deal of heat loss. Partly this is because they were a generation that had cheap coal and lots of deaths from infectious disease. However, it is made worse because some of the features were originally controlled manually. For instance, some tower louvres had long ropes that could be used to close the louvres while the building is heating up and in use, and then release the moist air from the service by opening the louvres for a while afterwards. Sometimes there are manual vents on windows, too. As a community, we need to develop a better understanding of how to obtain professional assessments of ventilation needs and recommendations for how to reduce ventilation without damaging our buildings, but thinking about how your building was designed to be used seems a good start.
Because it’s hard to control what users do in buildings, installing automatic ventilation controls can seem an attractive option. These provide the right amount of ventilation without users having to think about it. Professionals design them to provide the right number of air changes per hour for the type of space and to ensure moisture exits the building.
We don’t know what to say about this option because it’s hard to judge the benefit and the expense. It’s especially difficult for traditional buildings with high ceilings. Scaffolding is very expensive, so installation and maintenance would be major costs.
Meanwhile, keep in mind that the more you rely on radiant and contact heating instead of space heating, the less heat loss through excess ventilation matters. This is one way of working with the building you have instead of against it.
More information