HVAC/R Evacuation Quiz June 7, 2022, 7:03 am

Related Tech Tips

Zeroth Law of Thermodynamics
Zeroth? ZEROTH? is that even a word? Apparently so, because… SCIENCE. The zeroth law of thermodynamics establishes the relationship between multiple objects and a common state of balance between them. It is sometimes called the law of thermal equilibrium. Heat always tries to find a state of balance. “Hotter” is a relative term, but an […]
Read more
Heat Pump Defrost Boards and W2
If you are used to simple, straight cool split systems, you know that the low voltage to the outdoor unit is usually VERY simple with just a Y (contactor power) and a C (common) connected to the outdoor unit in many cases. When the condensing unit controls are strictly two-wire low voltage, there is no […]
Read more
Understanding Relays With the 90-340
Relays can be used for many different control applications, including controlling fans, blowers, other relays, or contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck. So, we will use it as an example. A relay is just a remotely controlled switch that […]
Read more

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from