What is an economizer? The simple answer is that it is a set of dampers on an air conditioner that allows the A/C unit to decide whether to heat or cool the air inside the building or outside the building. By selecting the air that requires the least heating or cooling the A/C unit will run much more efficiently and the result of that is it will cost a lot less to keep your building comfortable. A properly working economizer can save hundreds or even thousands of dollars per year depending on the particular building.
Don’t most commercial packaged air conditioning units already have an economizer? Yes, in most areas packaged commercial A/C units larger than 2000cfm (5 tons cooling) are required to have an integrated economizer. This is actually a plus to those of us that sell economizer controls. The fact is that any economizer more than three or four years old is probably not working properly. Many of them have been electrically bypassed or manually positioned so that they cannot open. By forcing them closed, you lose the free cooling that is provided by the cooler morning and evening outside temperatures in the mild months. By forcing them wide open, you are trying to cool the very hot outside air in the summer months and heat the very cold air in the winter months.
Economizer controls have been something of a mystery to most HVAC technicians in the past. There is no easy way to see if they are working properly or not, so most of time they are ignored. That decision is costing people a lot of money. If the economizer controls are more that a few years old they should be replaced.
Honeywell introduced a new line of JADE Economizers not too long ago and it solves most of the problems associated with the earlier devices. The enthalpy sensors are solid state electronic rather than Mylar ribbons that rapidly fatigue. The controllers have a screen display that shows you exactly what the system is doing at the time. It has checkout and troubleshooting capabilities that were not available before. Technicians can look at the system and know that it is operating correctly. It is a relatively inexpensive replacement system that will save money for the owner of the HVAC equipment immediately. For a building owner it should be an easy decision to make if they are made aware of the problem. I doubt that many owners realize that their equipment is not operating at maximum efficiency. I also doubt that they care because they have no idea what the benefit is to a working economizer.
I would recommend that anyone reading this article travel to this link at Honeywell’s website and look through the collateral material available. On this page you will see a savings estimator that can be used to determine the savings you should expect from your properly operating economizer. It also has design manuals and technical literature for both old and new controls.
I have spent many years working with HVAC contractors and technicians. In that time I have noticed that contractors are looking for sales opportunities and this is certainly one. It will only be successful if the field technicians understand the issue and present the problem to their customer immediately. They need to know the cost of ignoring the needed repair and they need to provide their customer with the importance of making the repairs promptly. This is a situation that is good for everyone! The customer will benefit from maximizing the efficiency of their HVAC equipment. The contractor will benefit by increasing their sales and George T. Hall Company will benefit because we provide the products and support necessary for the contractor to get the job done correctly the first time.
Three new economizer tools are now available for free to download at: http:customer.honeywell.com/economizertools.