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 …
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Economizers are in the spotlight as a prime opportunity for energy savings in the commercial HVAC marketplace. It’s said, with little argument from those in the field, that nearly 80% of air-side economizers are non-functional. So if that’s true, opportunity is calling any mechanical contractor willing to step up and take this bull by the …
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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 …
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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 …
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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 …
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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 …
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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 …
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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 …
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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 …
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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 …
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