Heat Exchanger Destroyer #1
By: Steve Holland
Design. The first place to look if you’ve lost a heat exchanger!
Who would have ever though that a designer could ruin a heat exchanger? It happens each and every day. There are three phases of design that cause heat exchangers to fail.
- The manufacturer design. Many manufacturers use proprietary methods when developing heat exchangers. Carrier, for example, had a secondary heat exchanger that used a poly-propylene coating. In some furnaces, this coating failed; resulting in secondary plugging and/or heat exchanger leakage. The Lennox Pulse was another that ran into a few issues. Today, we are seeing many designs that may pose failure in the future. Understand this, most heat exchangers fail as a result other than manufacturer design.
- The designer of the job. At Mr. Holland’s we call these folks “Comfort Advisors”. Many comfort advisors fail to properly measure duct systems, or fail to perform load calculations, resulting in pre-mature heat exchanger failures. This is why we require all of our comfort advisors to measure the home, measure duct systems, and, in some cases, perform a static duct pressure reading on the system.
- The install designer. Every furnace built and designed must be installed by the installation technician. This means that after the manufacturer builds the unit, and after the comfort advisor sizes and designs the job, it has to be installed. Many mistakes are made at this phase of the process, resulting in pre-mature failures of heating and cooling systems.
Never assume that just because your neighbor referred a company or the fact that an HVAC company has been in business a very long time that the job will be done properly. Pay attention to the following:
- Was a load calculation performed by the sales person?
- Did the sales person examine the ducting and perform a cfm or static duct reading?
- Are they accredited by the BBB?
- Make sure that the installing contractor gives you a complete workmanship guarantee in writing, and a host of other guarantees.
- Hold your sales staff accountable by making sure that they perform a load calculation and duct calculation.
- Stand behind your work
- Spend the extra money and get BBB (Better Business Bureau) accredited
- Quit being so cheap. Spend money on training, education and staff development
- Don’t be arrogant and think that your engineers are smarter than HVAC techs. They may know physics and properties of heat transfer – but, some simple changes from HVAC guys can give that furnace a better and healthier life.
- Use more stainless steel and good quality stainless. Many secondary heat exchangers fail because they are not made of stainless steel.
- Listen to your end-user customers. That’d be me and other HVAC contractors out there that install your equipment each and every day.
I hope that the information that I provided was useful. Remember, the best way to keep homeowners and customers safe is by training and educating service technicians.
“Changing the HVAC industry – one tech at a time”