Tech Tips

Courtesy of Emerson It is important to have refrigerant free from debris and contaminants, and we control these issues on many different fronts. 1. Proper tubing handling prevents copper shavings, dirt, and water from entering while installing. 2. Flowing nitrogen while brazing prevents carbon build-up. 3. Deep vacuum of 500 microns or less removes air, […]

To maintain combustion (burning), you need three things: fuel, heat, and oxygen. If you have all three in the proper proportion, you can maintain a continuous state of combustion. Remove one (or reduce one sufficiently), and the triangle of combustion can collapse. In a common natural gas (NG) furnace, the heat is the igniter, the […]

Server rooms, sometimes called data rooms, are a somewhat unique situation in the HVAC trade with some special circumstances that should be considered. Here are a few tips for success when working on equipment for these spaces. Note: this article is focused on smaller server rooms that may use conventional or mini-split-type forced air equipment. […]

Every gas furnace data plate/tag has a specification for the temperature rise through that furnace. It is shown in a range like 50-80° or 45-75°. Those first two numbers are the lowest recommended temperature rise; the highest allowed temperature rise through the furnace is usually a 30° difference. When possible, we want to get the rise […]

Marley was dead, to begin with. There is no doubt whatever about that. That's the way Charles Dickens begins his “A Christmas Carol,” one of the most well-known pieces of literature in the modern world. A short story that can be read aloud in a few hours has to start memorably, and this one certainly […]

This gas furnace maintenance procedure in this article was developed by Michael Housh. Michael is the owner of Housh Home Energy in Ohio. He regularly works on natural gas equipment and is an active contributor to the HVAC School Facebook group. Thanks, Michael! Gas-fired equipment has a different set of components than your typical straight-cool […]

The Sleeper  The year was 2002, and I was 20 years old. I had a helper named Clay, and he was a really nice guy, probably 15 years my senior, already with streaks of grey in his hair with a way of making you feel at ease—so very at ease. OK, he was sleeping most […]

We have discussed many methods for checking a refrigerant charge without connecting gauges over the last few years. Recently, I've been thinking about the “approach” method of charging that many Lennox systems require. What is the Approach Method? The “approach” simply refers to the temperature difference between the liquid line leaving the condenser and the […]

This article was written by Don Gillis with Chemours. Thanks, Don! With the American Innovation Act (The AIM Act) in place and the reduction of the supply of hydrofluorocarbons (HFCs) in effect, the need to retrofit systems with lower global warming potential (GWP) refrigerants will become commonplace in the very near future. So, what does […]