In residential air handler/fan coils, it is common to use a high-voltage interlock between the blower and the electric heat strips to ensure that the blower comes on whenever the heat is on. The problem is that it CANNOT work the other way around where the heat comes on with the blower. Heat strips are […]

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 […]

UPDATED VERSION AS OF 4/1/2020 As HVAC contractors, we are tasked with keeping staff and customers safe during the outbreak, and we are relied upon to provide some guidance to customers about how to protect themselves against the virus in the air. For employers and employees looking to navigate the new FMLA/FFRCA legislation, we put […]