Tech Tips

Pioneers of refrigeration The modern world is impossible to imagine without refrigeration. The Internet, food transportation, medical imaging, and vaccine research all rely on refrigeration to function. Even the sprawl of cities across the American south in the 1950s was inconceivable without refrigeration and air conditioning. So, if you like vacationing in Vegas or taking […]

In the trade, we talk a lot about changes in enthalpy, especially when we are looking at total heat exchange over an evaporator. Sometimes, you will bump into the word entropy, and I wanted to take a stab at making it more understandable. Many people understand entropy as the condition in which molecules become more […]

In HVAC systems, liquid and vapor will exist at the same time and place. We call that condition saturation, or we say that the refrigerant is “at saturation.” Phase changes occur in the evaporator and condenser, so these are spots where liquid and vapor coexist while the system is running. Saturated conditions occur whenever liquid […]

Compressibility is the ability of a substance to be squeezed into a smaller volume. It is the change in volume and increase in density that results from an increase in pressure. The subject of compression should be familiar to HVAC techs. After the return air passes over the boiling refrigerant in the evaporator coils, the […]

Ductless systems didn’t gain popularity in North America until relatively recently. However, it’s no surprise that they’re becoming quite common. They are quiet, efficient, and well worth the price in the long run. Highwall ductless systems have their downsides, though. When they get dirty, they can spread gunk beneath them and make a room smell […]

This article is based on Ross Trethewey’s energy comparison sheet for fuels at select efficiencies and costs. All tables and their respective data belong to him. Ross Trethewey is the founder and lead engineer of TE2 Engineering and has served as the Home Technology Expert on “This Old House.” You can find a PDF file […]

This article was written by Regan Murphy. Thanks, Regan! Disclaimer: Any percentages used are the opinion of the author and not based on any actual facts. You are probably already used to getting the model and serial numbers of the equipment. You may have even made a habit of getting the part number, but there […]

The way we use and think of refrigerants is evolving quite rapidly. As we shift towards phasing out ozone-depleting refrigerants and considering alternatives, the future of refrigerants may seem a little uncertain to us. However, one thing is certain. Many HVAC units will continue to rely on the common HCFC, HFC, and HFO refrigerants we […]

Even though there will almost surely be a healthy demand for HVAC service businesses, any service business is still at risk of going under. Most of the trouble comes down to money mismanagement or misunderstanding. The good news is that the risks are avoidable with proper education and care. We aren’t accountants or lawyers, but […]