Most techs and installers know that drains need to be pitched. I use the rule of thumb that drain lines should generally be pitched 1/4″ per foot of horizontal run. One thing that can easily be forgotten is pitching wall penetrations when drilling. It's as simple as drilling with a slight upward angle if drilling […]

There is a lot of misunderstanding about the HSO (hard shut-off) or “non-bleed” TXV (thermostat expansion valve) and what makes it shut off, why it exists, and how it “magically” opens. Once you understand the forces inside the valve, it is quite simple, obvious, and sadly devoid of any magic. The Three Forces  The TXV […]

In HVAC and electrical school, one of the first things you learn about electricity is Ohm's law: Volts (V) = Amps (I) x Ohms (R) Pretty simple, right? Watt's law is just as easy: Watts (P) = Volts (E) x Amps (I) With this newfound knowledge, the student walks confidently into the real world with […]