Modulation motors are not often seen in residential equipment, but we see them a lot in commercial and industrial applications on many different types of equipment. I see them primarily on larger burners to control the fuel firing rate, but they also control water flow through heating coils, the water level on cooling towers, and […]

This article was written by HVAC/furnace technician Benoît Mongeau. Thank you, Ben.     High efficiency (or 90%, or condensing) furnaces use a set of two heat exchangers to retrieve more heat from the combustion products than their mid-efficiency counterparts. Because of this, they generate flue gases much colder than those of a mid-efficiency or […]

The gas laws. We all learned about them in school and promptly forgot all about them. I really think that we need to dig our books out, dust that information off, and work to understand and apply it. Many will say that nitrogen pressure doesn't change with pressure like other gasses. That is false, but […]