A lot of proper duct design comes down to an understanding of available static pressure and friction rate. We've covered this topic several times on this site and the podcast, but I wanted to focus on this ACCA chart specifically (shown above). ASP The horizontal axis is available static pressure or ASP, and it's indicated […]

Every gas furnace data plate/tag has a specification for the temperature rise through that furnace. It is shown in a range, like 50-80° or 45-75°. Those two numbers are the lowest recommended temperature rise, and the highest allowed temperature rise through the furnace is usually a 30° difference. When possible, we want to get the rise […]

A quick note about UV lights: they work like sunlight in that they prevent and kill many types of bacteria and fungi when exposed to the light on surfaces. They do not generally do a great job of killing spores suspended in the air stream. UV lights are great at killing yucky stuff on surfaces […]