The quest for greater energy efficiency has been promoted by the government using utility company programs for more than a quarter of a century. This movement has made consumers aware that higher efficiency equipment is the right thing to use. Manufacturers have responded with higher efficiency equipment and contractors have consistently been able to increase …
Read more
Air filters create resistance to airflow that can reduce a fan’s ability to move air by up to 50%. You can evaluate the filter’s impact on airflow by measuring the pressure drop over it. It takes less than a minute to do. It is often the diagnostic test that identifies the problem in nearly one …
Read more
What makes modular or two-piece different from their single-piece cousins when it comes to measuring total external static pressure (TESP)? In this article we’ll examine the differences and discuss how to measure TESP correctly. “As-Shipped” The “As-Shipped” idea is helpful when measuring the TESP of two-piece air handlers. So, what do you find when you …
Read more
I hear a lot of reasons for taking static pressure measurements on every service call. One of the most common is that it takes too long — there isn’t enough time on a call to do it. Let’s face it, technicians have a lot of responsibilities and measuring static pressure adds to them. What if …
Read more
Many technicians who work on fuel-fired equipment will admit they’ve singed their eyebrows when watching a burner light. It’s a rite of passage among most seasoned technicians. What if there was a safer way to check ignition instead of sticking your face in front of a burner? Fortunately, there is, and it involves using a …
Read more
Chances are high that you’ve encountered disastrous equipment replacement jobs you’d love to forget. Whether it’s the customer who now has high humidity issues, or the system that can’t maintain temperature anymore — we’ve all experienced them. Indeed, in many of these occurrences, attention to detail and avoiding bad industry habits helps prevent the occasional …
Read more
Measuring static pressure on air handling equipment that has variable-speed fans can be a challenge to both new and experienced technicians. By addressing a few details, your readings will be consistent when you encounter this blower type. Let’s look at three tips you can use the next time you measure static pressure on a variable-speed …
Read more
Many technicians get distressed when they measure draft pressure in the flue and discover the reading is zero. Let’s look at three common reasons for zero draft pressure in a flue. We’ll also determine what defect you’re dealing with. Reason #1: Zero Draft from Building Depressurization Building depressurization is probably the most common reason for …
Read more
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
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
