HVAC

The two documents that set whole-house ventilation rates give formulas that look like the same equation and are not. The...

Whole-house ventilation is sized from two numbers every contractor already has: conditioned floor area and bedroom count. What makes it...

Whole-house ventilation fails in a small number of recognisable ways, and the symptom almost always names the cause. A measured...

A dry-bulb split sees only sensible heat. Adding a wet bulb at the return and the supply turns four temperatures...

The capacity equation has no empirical term, so a wrong answer is a wrong input. A diagnostic order for negative...

Two air-side checks that answer different questions. What delta-T is genuinely good at, the three things it structurally cannot see...

Where each input genuinely comes from, how to read the rating points on an AHRI certificate, the load line and...

A diagnostic order for backup heat that runs more than the balance point says it should: prove it with an...