Which type of chimney is more prone to depressurization issues?

Chimneys with short heights are more prone to depressurization issues due to their reduced ability to create sufficient draft. Draft is the upward movement of air through the chimney, which is essential for effective venting of combustion gases. A taller chimney can produce a stronger draft because it can take advantage of the temperature difference between the hot gases rising from the fireplace or appliance and the cooler ambient air outside.

When a chimney is short, it may not extend past the roofline sufficiently to catch the natural draft created by the wind or the thermal differences. This lack of height can lead to negative pressure situations inside the chimney, making it difficult for combustion gases to flow out efficiently. This can result in a backdraft or cause exhaust gases to spill into the living space instead of being vented outside properly.

While other chimney types may have their own issues, short chimneys specifically struggle with maintaining adequate draft due to their height, making them particularly vulnerable to depressurization problems.