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 […]

When brazing and soldering, we have a few things we need to accomplish to make a proper connection: We can't overheat the joint until it overheats the base metal or the flux where applicable. We must bring the entire joint above the melting temperature of the brazing alloy. Draw the alloy deep into the joint. […]

Here is another excellent article from Michael Housh, owner of Housh Home Energy and a regular contributor to HVAC School. Thanks, Michael! I thought I would go through a simple example of sizing a hydronic circulator for an application. This is a made-up scenario, but I sketched out a 20’ x 20’ square home with […]