Testo SA has donated a thermal imager to the OTTC training centre in Springs to do their part in upping the skills in the local HVAC&R industry. This has been met by great interest from the students as they explore the possibilities of improved maintenance with this handy instrument.

Testo has donated a thermal imager to OTTC. From left: Martin McEneaney-Nel (OTTC training manager), Clement Steenkamp (Testo South Africa); Isolde Dobelin (OTTC director), and Hannes van Rooyen (OTTC training manager).

“Testo South Africa wants to assist the local HVAC&R industry in functioning better,” explains Clement Steenkamp, Testo SA’s sales and market manager. “By introducing technologies not currently fully used in the HVAC&R industry, via training institutes such as the OTTC, we allow students to help industry run more efficiently. With energy costs ever rising, we believe that energy efficiency and preventative maintenance are vital topics that must be addressed. Our sponsorship of a thermal camera to the OTTC is a small step in the right direction.”

Climate change and the growing demand for energy, when at the same time fossil energy sources are getting ever scarcer, represent one of the greatest global challenges. Because a relevant proportion of emissions involve the building sector, special efforts are needed in this area to achieve the internationally agreed climate objectives, explains Steenkamp.

testo00 2The thermal imager can be used to pick up faults on compressors, making maintenance much easier for technicians.

Enhancing skills

Since receiving the imager in October 2018, OTTC training manager McEneaney-Nel has been showing new students how it works to highlight its potential for making their jobs easier on site. “There is so much you can do with a thermal imager,” he explains. “But you need to know what you are looking at.” That’s why he is teaching students how to think of fault-finding in terms of temperature.

McEneaney-Nel believes that every HVAC&R company should have one of these imagers. It’s not only useful for maintenance but can add great value to commissioning too. “In Europe, every professional has one of these – it’s the norm. But for South Africa it’s still a bit slow on the uptake.” He’s hoping that by familiarising students with the tool, they will motivate its necessity to their companies and increase their popularity locally.

testo00 3Martin McEneaney-Nel demonstrates the temperature difference across a cold room fan.

Potential uses

A large part of heating energy is lost through poorly insulated walls, roofs and windows. Effective insulation therefore not only saves costs, but also protects the environment through lower CO2 emissions. Thermography is a method for checking the actual condition of buildings and the potential for energy savings. Both hidden weak spots and implementation defects can be detected non-destructively, and their causes determined. The detection of these defects applies to the electrical and mechanical sections of heating and cooling systems along with insulation checks.

testo00 4The expansion valve as seen through the thermal imaging camera.

Overheated connections in a control cabinet indicate potential or actual defects. These can range from loose contacts or overloaded circuits to faulty contactors and relays. A thermal imager can detect aforementioned anomalies without contact and during operation, before downtimes can even occur. Mechanical parts will either generate heat or transport it. In a similar way potential defects can be detected while the system is in full operation. The condition of motors, expansion valves and compressors can easily be assessed.

testo00 5A Bitzer compressor as seen through the thermal imager.

Thermal imagers can also be used to detect:

  • Warn out contactors and relays: heats up as contacts wear out.
  • Overloaded circuits (especially on three-phase): it is easy to see if a load is unbalanced.
  • Poor electrical connections: will create higher resistance and heat/fire that can be prevented.
  • Fan motors: will show heat before failing.
  • Warn out bearings and pulleys: will create heat before seizing.
  • Misaligned belts: belt will heat up from friction.
  • Poor insulation in cold rooms: see heat leaks.
  • Can detect condensed liquid columns in large installations where gas is supposed to flow.
  • Can very quickly measure condenser and evaporator temperatures.
  • Compressors that have leaking valves will heat up.
  • Any additional moving mechanical parts that are not lubricated or worn out will generate heat.

“The strength of the thermal camera technology is that it is not limited to a specific list of applications since new applications are found all the time,” says Steenkamp. “This is especially true of the HVAC&R industry where all we deal with is moving parts and heat transfer.”

testo00 6OTTC training manager, Martin McEneaney-Nel showing students how the new thermal imager works