Combustion Air in a Gas-Fired boiler

Safe operation of any fuel-fired equipment requires adequate combustion air supply. To provide this essential system component, technicians typically install openings constructed of metal ducts or fixed grilles. This provides air from the outside or from an adjoining part of a building. Since combustion air openings are ducts, let’s look at the variables affecting airflow …
Read more

With the end of the heating season there’s a tendency to forget the dangers of carbon monoxide (CO). As you transition to the cooling season, be sure to keep your awareness for CO high even though it’s likely to be the last thing on your mind. Let’s look at five summer CO issues you should …
Read more

HVAC Air Filter Media

If you’ve been in the HVAC industry for any length of time, you’re familiar with complaints involving dust and dirty equipment. As a result, most technicians target the air filter first when they receive such calls. As you investigate these problems, keep in mind how the following ways reduce filtration effectiveness so you can more …
Read more

Stacked pebbles represent stability in HVAC systems

When testing and diagnosing the operation and performance of an HVAC system, the timing and measurement are critical. Ideally, the system should be calling for full heating or cooling, and fan speed so it can reach a stable operating condition. Let’s take a closer look at what constitutes stable operating conditions so your test data …
Read more

When it comes to ethics, I love to tell this story. I once called a plumbing service company to investigate a leak in our shower above the kitchen. They quoted me $195.00 for the work. Two hours later I had five holes in my kitchen ceiling, a messy bathroom, and no conclusive source of the …
Read more

Heat exchangers

The connections between a furnace and duct system are rarely considered as a cause of cracked heat exchangers. Commonly repeated mistakes with return and supply duct connections significantly impact airflow and the length of time before you’re back for repairs. Let’s look at some these issues that may be killing airflow and the heat exchangers …
Read more

CO - What Do You Know?

Many HVAC professionals assume the leading cause of carbon monoxide (CO) poisoning is a cracked heat exchanger. This assumption leads to inaccurate test methods that pass on from technician to technician. They try to assure customer safety, but unknowingly rely on misinformation. No one wins in this scenario — both the contractor and customer have …
Read more

Avoid sharp turns

Flex ducts could be in imminent danger. A few months ago, I wrote about a recent proposal to severely limit the use of flexible (flex) ducts. Due to poor installation methods, the International Association of Plumbing and Mechanical Officials (IAPMO) is proposing to limit use of flexible duct to only five feet in length. How …
Read more

Carbon monoxide (CO) poisoning is one of those scary issues that most HVAC professionals hope to never encounter. As with many frightening things we want to avoid, this doesn’t make those issues go away. The threat is very real even though contractors often turn a blind eye to it. With all the stories and reports …
Read more

HVAC Airflow and leaf blowing -- the common denominator

Let’s talk airflow. We live back in the woods on a half-acre with fifteen 100-foot tall oak trees. For years I’ve imagined sharing leaf blowing airflow lessons with my fellow airheads. Let’s take a look at the mad airflow skills you can master while blowing leaves. Fascinating Statistics “If you don’t measure, you’re just guessing.” …
Read more