Hvac School - For Techs, By Techs

In this short Q&A podcast episode, Bryan answers Gunther's question about kitchen exhaust and makeup air. Gunther asked if there were any studies that showed that makeup air should come very close to the hood to avoid infiltration. He also asked how to educate others who push back against the idea, particularly in kitchen exhaust systems of around 600 CFM. Commercial facilities, especially restaurants, bring in makeup air to balance out the air being exhausted. There are costs associated with makeup air, but there are plenty of valid reasons to add it to residential structures. Being able to control the makeup air allows us to control where we bring air in from (especially when it comes to drawing in humid air or dirty attic air from gaps and cracks, particularly in vented attics). Open-combustion appliances in the building envelope are also prone to backdrafting if the structure is under negative pressure. The structure is also more likely to have its dryer vents experience leaks under negative pressure.