In the context of refrigeration systems, what does the term 'make-up air' refer to?

The term 'make-up air' in the context of refrigeration systems specifically refers to the fresh air supplied to maintain building or system pressure. In many mechanical and HVAC applications, especially where there are exhaust systems, it's vital to ensure there is a sufficient volume of air within the space to prevent negative pressure effects. When air is exhausted from a space—either from air conditioning systems, kitchens, or other processes—make-up air is introduced to replace that lost volume.

This is essential not only for maintaining comfort but also for the proper function of combustion appliances, ensuring that they have enough air to operate safely and efficiently. Proper ventilation and the introduction of make-up air help to prevent issues such as drafts, odors, and pressure imbalances, which can affect both the comfort level and the efficiency of the refrigeration system.