The Two Big Questions
The first question screaming for an answer is why are such a large percentage of economizers non-functional? The word on the street is most economizers are manufactured just to satisfy code compliance for new construction. That means many economizers are cheaply built and have an extremely short life expectancy.
If this is true, it may explain the 80% non-functioning economizer number. Or, is the real answer in the next question?
Why aren’t economizers being repaired? Another interesting number circulating in the field is that 80% of economizers are never commissioned when installed. This statistic and the answer to the question at hand, points the finger directly at the HVAC industry. In reality, few installers or contractors really know how to commission an economizer or how to set the controller for local weather conditions. Even fewer really know how to measure and set airflow through the economizer.
So, the bottom line may be, as an industry we lack the knowledge to keep our customers in free cooling. If that is the case, the greater the opportunities are for companies willing to specialize in economizer repairs and upgrades.
Top 10 Economizer Opportunities
Interviews with several top commercial contractors in areas of the country where economizers pay off handsomely created this ‘Top Ten’ list of economizer defects. These are defects most frequently discovered in the field. It’s interesting to see how little it takes to get an economizer back up and running to deliver free cooling when outside conditions are right.
Number One - Unplugged economizers. The number of economizers with this classic problem are so great that the problem begs a closer look. It seems the only reason economizers are unplugged is because many installers are so unfamiliar with what it takes to set up an economizer that they don’t even try. That brings us back to the opportunity; it may be much greater than any of us anticipated.
Number Two - Frozen actuators. If economizers are as cheap as indicated, this would support the decision to replace a locked up actuator with a new one that may last the life of the equipment. That brings us to selling repairs. In order for a commercial building owner to agree to pay for an economizer reconditioning there usually needs to be a payback on the investment in his building. To calculate economizer savings in your area, check out this free download tool at https://customer.honeywell.com/en-US/support/commercial/se/ese/Pages/default.aspx. This is an easy-to-use tool that quickly enables an HVAC professional to calculate the payback on economizers. It’s simple to use and the price is right.
Number Three – The economizer is not commissioned at start-up. This opportunity is derived from contractors that fail to train their installation crews. You know…those low bidders that take the job for bottom dollar and the customer pays the difference over and over again in the years that follow. Oh, you haven’t trained your installers in economizer commissioning? We need to talk.
Number Four - Carbon Dioxide sensors are out of calibration. Economizer sensor lifespan and accuracy are both increasing rapidly as technology advances. Demand control ventilation is in fashion and it just makes sense. Today’s sensors have much to offer and are often easy change-out options for aging or inaccurate sensors. A short conversation with your controls vendor will shed some light on this opportunity.
Number Five - Louvers or dampers are jammed open. Louvers need maintenance too. They get dirty, bind up and are tied to other economizer components that can affect their performance. Be sure to include manipulating the louvers open and closed in your service agreements to assure louvers can do their job. This includes louvers that got screwed shut on those extra hot days last month.
Number Six - Damaged actuator motor fiber gear assemblies. Only the best technicians take time and effort to watch an economizer cycle inspecting for evidence of stripped cogs in these wheels that have worn out. As they do, the louver position changes a little with each cycle and can really mess up louver airflow settings. Replacement gears are available and should be kept on hand and replaced often.
Number Seven - Pre-filter is damaged or missing. Air filters located in the intake of an economizer are easy to overlook. Keeping those filters clean can make a big difference in long-term economizer operation and in extending the life of components that should, ideally, remain clean.
Number Eight- RH sensors are out of calibration. Only the best technicians carry the 33% and 75% pots of saline solution on their trucks to calibrate these sensors. Some older sensors actually need recalibration every 3-6 months, believe it or not. Best practice is to replace old sensors with new ones that are more accurate and dependable.
Number Nine - Damaged or loose linkage. Adjusting linkage is an art unto itself. Doing so requires patience and skill. Taking the time to drive economizers open and closed is the only realistic way to check linkage operation and functionality. Tighten regularly and don’t forget to measure economizer airflow.
Number Ten- Corroded wiring. So how long does economizer wiring last in your part of the country? Good contractors make a practice of salvaging old economizers when replacing equipment and use them as trainers to provide hands-on rewiring exercises. That’s a good idea, give it a try.
So, as you can see, economizer opportunity abounds. If you are in an area of the country where economizers make great sense, consider investing a little time and a few marketing dollars preparing your service department for a great harvest. Fall is coming. Free air conditioning will be everywhere.
Rob “Doc” Falke serves the industry as president of National Comfort Institute an HVAC based training company and membership organization. If you're an HVAC contractor or technician interested in a free procedure to measure economizer airflow, contact Doc at [email protected] or call him at 800-633-7058. Go to NCI’s website at nationalcomfortinstitute.com for free information, articles and downloads.