HOW TO REDESIGN A DUCT SYSTEM
e redesign duct systems because they don’t perform as they should. Have you ever stuck new equipment on an existing duct system assuming the old ducting worked just fine? If I were your daddy, I’d say “shame on you!...
BALANCING A ZONING SYSTEM
The whole idea behind zoning HVAC systems is to deliver the correct amount of air to the right place. Balancing a zoned system is even more critical because of design complexity and constantly changing airflows, temperatures and pressures. Balancing is also a very profitable add-on sale to any zoning system installation. ...
FRESH AIR FOR VENTILATION AND BUILDING PRESSURIZATION
Adding fresh air to a heating or cooling system accomplishes two primary Indoor Air Quality (IAQ) goals: First, it controls building pressures and secondly, it increases IAQ by diluting polluted or stale indoor air....
Finding System-Required Airflow
When it comes to diagnosing the airside of a heating or cooling system, start with equipment model number. Once you know the equipment size, you can calculate the required airflow, which is expressed in cfm. (Cubic Feet per Minute) Then you can compare measured airflow to required airflow as the foundation to your diagnostic testing. ...
WE LEARN A LOT FROM OUR DADS
Many of us became HVAC professionals because of our Dads. For decades, HVAC Dad's have handed down their passion to serve others by bringing us into the trade. If that's your story, I'd encourage you to take some time to record the events and memories of how your father wielded his influence on your profession....
HOW FANS REALLY WORK
The fan turns and the air moves, right? But there are a few basic principles governing airflow with residential constant speed fans that are frequently...
ARE YOU COSIDERING ADDING SERVICES?
I enjoyed a conversation recently with a long-time successful contractor from California. He was considering adding duct cleaning to the services his company offers to their customers. It was interesting that he described the proposed venture as "a temptation he had resisted for decades." Considering his quandary, what new services have you been tempted to add to your company recently?...
IS GREEN CLOSING IN ON YOU?
We have all seen contractors wrinkle their noses when the topic of "green" is introduced into a conversation. Why is it that so many of us contractors quickly change the subject when we feel green closing in on us? Have the friends of the environment pushed way too hard and accomplished way too little in the eyes of the typical HVAC contractor? That’s what I hear....
HOW TO FIND FAN AIRFLOW
Each furnace or air handler has its own peculiar air moving characteristics. So how can you figure out what the fan your working on it supposed to be doing? There is no single source for this information, but hopefully this article can guide you in your search for this essential data....
MEASURE HEAT STRIP PERFORMANCE
Since the cold has set in, we've received many calls and e-mails from contractors and technicians wresting with electric heat systems. The two main concerns are: How to determine and rate electric heater performance; and how to figure the right amount of airflow to safely increase or decrease supply air temperatures. Let’s take a closer look....
USING VARIABLE SPEED MOTORS AND STATIC PRESSURE
A number of years ago when variable speed fans began to become popular, their primary benefit was promoted to be their ability to overcome airflow issues in poorly performing duct systems....
Fast Money At the Quick Lube
We all make mistakes as we evolve our businesses. Each of us can probably tell a few exciting stories about failures we’ve experienced, and hopefully, enough time has passed so we can finally chuckle about them. I was on the receiving end of a sales experience recently where I was doing the chuckling and the service provider didn’t have a clue how quickly he was exterminating any chance of a lasting business relationship....
Two Kinds of Activists
The flight into Portland, Oregon was bumpy and delayed, but I was excited to get there. I wasn’t in the usual business mode — Hugs from my Grandkids would soon greet me at the airport and I was daydreaming of Opa’s weekend with Galla and Finn, a one and two year old that make me feel young again....
Build Safety Clauses into Your Proposals
If you think back over your career in this industry, undoubtedly you have learned a few hard lessons. One way to leverage the value of these lessons is to add a layer of protection into the proposals that you offer your customers. The official name of these clauses is proposal conditions. Let's review a few of them just to get you thinking....
Profiling an HVAC System
While profiling may be an unpopular word in airports these days, it remains the title of one of the best diagnostic procedures you can use to diagnose an HVAC system. You can profile an HVAC system by talking a series of temperature, pressure or airflow readings across it, and recording them on a system schematic. Studying the profile makes apparent system defects that may not become visible by any other means. ...
Price Duct Renovation for What it's Worth
Duct renovation work is increasing at a steady clip across the country. Our industry is embracing the idea that just replacing the equipment isn't that great of a service to our customers without taking the time to get the duct system right at the same time....
Learn from the Raters
By now, most of us have met up with a HERS Rater or two. HERS stands for Home Energy Rating System. These forks are used by government and utility programs to rate the performance of homes so builders and homeowners can receive tax breaks and utility incentives. Quite a number of them are great building and HVAC system performance testers. I've written about these folks several times, because like it or not, they are becoming a very real presence in our industry....
Don't Exceed Your Static Pressure Budgets Part 1
When it comes to budgets, our household spending is something we all can relate to. Just before the next check arrives there are several feelings we can experience. If you've spent less than what you've made, all is well. If you've spent more than what you've made you may feel the immediate pain of an overdraft charge, or the long term suffering of painful and expensive growing credit card debt....
Don't Exceed Your Static Pressure Budgets Part 2
Keeping in mind that the general idea is to keep the system's static pressure at or below 100% of the air handler's rated total external static pressure, we found the following pressure budgets for each of the following system components in well-performing systems across the country....
Duct Renovation Opportunites
Duct renovation has become one of the hottest topics in the industry today. Attention is being drawn to the substantial benefits it provides for both the contractor and the homeowner since the duct system often has more of an effect on system performance than the energy efficiency rating of the equipment....
Let the Student Teach
Put yourself in these shoes: There's this seminar you've wanted to go to for a long time. It comes to town and you're given the chance to attend. The day before you go, you're asked to deliver a 30 minute summary of what you've learned Friday morning in your company's weekly training meeting....
Anyone Can Measure Static Pressure, Part 2
In the last newsletter, we began a review of how to measure static pressure in an HVAC system. We discussed the required instruments and why measuring static pressure is such a good idea and a critical service we should be offering our customers. Let’s take a look and the steps required to measure total external static pressure....
Anyone Can Measure Static Pressure, Part 1
Manometers or pressure gauges have been used to measure air pressures for more than 200 years. The fathers of our industry used these gauges to learn about the mysteries of fans and duct systems. We use these same instruments (Although a little updated) to reveal similar mysteries about the systems we install and service today. Measuring pressure is just as critical in our time....
The Tight Duct Myth
Tight ducts are not necessarily right ducts. Although critical to a well-performing system, the disaster of the duct blower craze across the country has produced the single largest inventory of poorly performing duct systems that we have ever had the opportunity to harvest....
Flush The Tech Talk
Our customers are different creatures that they were a decade ago; and they’re a whole new species than what they were in the 1980s. Some of us old timers remember scribbling a model number and a price on a proposal, pushing it across the table and hearing them mumble, "Well, if you think this is what we need . . .," as they signed the paper....
