Tech Tips

Air-to-water pool heat pumps are seeing more and more popularity in the climates that can support them over the more traditional gas and electric pool heaters we usually see. While they definitely contain some familiar operating principles to an air-to-air heat pump, there are some striking differences in how the heat is transferred and how […]

If you remember my recent article on the company that went to my friend's house for a PM and did nothing but leave a system quote. Well, it got worse… My friend Josh left them a D-rated review on a popular review site, and the owner of the company responded with… an apology? A bottle […]

I once had an old commercial blower assembly on a 20-ton package unit, and the bearings and pulleys were seriously shot. I was 19 or 20, and as much as I tried, I just couldn't get the rusted hunk of metal apart. I tried penetrating oil, pullers, pry bars… I knew better than to beat […]

Testo 760 Category IV Multimeter I was standing at a booth at the HVAC Excellence Educators conference, and an instructor walks up, grabs a meter, and asks me, “What's the difference between a category 3 and a category 4 meter?” Well, I really wasn't sure, but I knew that the category 4 meter is rated […]

We all have some weird tools we keep in our tool bags. A baster may look suspicious, but it comes in really handy for removing water from a float switch. This one is extra handy because it comes with a nice tapered bottle brush inside it that works great to clean out the outlet port […]

Let's take a walk through the startup and commissioning procedure of a conventional or “single” refrigeration condensing unit. We’re going to start with a unit that is fully piped in and has been pressurized for leak and strength testing. For brevity, we are going to assume a basic familiarity with industry standards, company and customer […]

If you don't do a lot of commercial work, you may see a system like the one above and wonder what the heck it is. It is a 100% fresh air unit or a makeup air unit. You will see them more and more as codes start to reflect that balanced ventilation and conditioned outdoor […]

Our technician, Sam, sauntered into my office this afternoon like techs often do on a slow spring afternoon before the summer hits. It's been a long day for me, lots of training prep, a bunch of little fires, and errands to stomp out, and I still didn't get my article for the day written. I […]

The chart above is from a Carrier heat pump, and it lists some common accessories. I have heard this common pressure switch (last on the list) called a low-pressure switch (because it opens on fall in pressure) and a high-pressure switch (because it's in the liquid line), but RARELY do I hear it called its […]