#hvac

Enthalpy is easy. It's just a state function that depends only on the prevailing equilibrium state identified by the system's internal energy, pressure, and volume. It is an extensive quantity. Simple. Like most things, the scientific definition is as clear as mud. In HVAC/R, we use enthalpy measurement to come up with the total heat […]

I was talking about dry contacts with one of my techs, and he looked at me like I had three heads—and one of them was on fire. So, I figured it would be good to cover the difference between wet and dry contacts in a tech tip. Basically, “dry” contacts are switches with no shared […]

If you are new to the trade, I'd like to welcome you. Like many skilled trades, the HVAC/R trade has many opportunities and can help you make a good living. If you are young and new to the trade, we need you. We are grateful to have you. However, if you aren't thoughtful, you might […]

We all learned how to read the tonnage off of a model number within a few weeks of beginning in the trade. What you may (or may not) have learned is that just because something has an 036 in the model number, that does NOT mean it actually produces 36,000 BTU/hr. It doesn't reach the […]

First, let's state the obvious and clear the air a bit. The photo above is SUPER CHEESY! But this story is about three bad techs who don't know it, so a photo of three models clearly posing in clean clothes makes as good of a proxy for a bad tech as anything else. First off, I'm […]

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 […]

Most of the content in this article is based on Alex Meaney’s contribution to the HVAC School podcast in the October 2nd, 2020 episode: “How to Get The Most From Online Education,” which you can listen to HERE. Attending a class from your bedroom or home office sounds very convenient, right? That was probably what […]

Nomenclature on HVAC/R equipment is a sequence of numbers and letters a manufacturer uses to speak directly to the technician. Lots of initial upfront information is handed to the technician by the manufacturer the moment the technician reads the nomenclature in the model and serial numbers. So, how do we make sense of these seemingly […]

I’ve seen a lot of guys recently who reach for the motor puller tool first thing when attempting to remove a blower motor from a wheel/fan blade. Motor puller tools are an awesome backup tool when needed, but using a motor puller tool shouldn’t be the go-to method of removing a motor. The main issue […]

 This episode dives into an interesting and pragmatic discussion about how HVAC contractors can better balance their workload throughout the year. Kevin from Haven shares insights from observing HVAC businesses across the country and how some are taking a more strategic approach to triaging work. The main idea is to get systems up and […]

This podcast episode is Part 1 of a Kalos class on rack refrigeration given by Matthew Taylor. This first segment focuses on the basic refrigerant circuit and oil management of a parallel rack system, common in market refrigeration. Parallel racks follow the same general process as any other compression refrigeration system. However, they contain multiple […]

In Part 2 of the Rack Refrigeration Class at Kalos Services, Matthew Taylor discusses safeties, service, and more. Part 1 focuses more on the basic refrigeration circuit of a rack refrigeration system. When safeties are piped together, we have to keep in mind that they're a bit more complex than most HVAC refrigeration systems, especially […]

 Standard 310 is a technical workflow created by ACCA, ResNet, and ANSI for grading the installation of HVAC systems, typically in new home construction. It plays a crucial role in obtaining Energy Star certification, which can qualify homeowners for tax credits under the Inflation Reduction Act. The five steps of Standard 310 are design […]

 In this short Q&A podcast episode, Bryan answers Gunther's question about kitchen exhaust and makeup air. Gunther asked if there were any studies that showed that makeup air should come very close to the hood to avoid infiltration. He also asked how to educate others who push back against the idea, particularly in kitchen […]

 This episode featured Bryan Orr interviewing Sam Myers, the building science consultant at Retrotec. Retrotec manufactures products like blower doors and duct testers for measuring air tightness and leakage in buildings. Sam discussed his role at Retrotec, which involves training contractors on using their tools properly, product design, software testing, presenting at conferences, and […]

In this short Q&A podcast episode, Bryan answers Jeremy's question about checking the charge on rooftop units, and he gives some RTU tips. Rooftop units often come in sets, so you can use a thermal camera to look at all of the RTUs and compare them. A thermal imaging camera may even show you where […]

 In this short Q&A episode, Bryan answers podcast listener Cooper's question about starting an internal training program. Eugene Silberstein has been on the podcast before to offer his perspective on this topic, which you can listen to HERE. Bryan recommends a combination approach: instructor-led, hands-on, and self-paced learning, all deployed together. Hands-on learning often gets […]

 This episode features an insightful conversation with Brynn Cooksey, an experienced HVAC contractor and trainer from Southeast Michigan. Brynnn shares his expertise on conducting proper load calculations, sizing equipment correctly, improving duct design, and addressing common issues contractors face. Brynn emphasizes the importance of performing accurate load calculations, especially in older housing stock where […]