Thermal Imaging with Digital Photography

Thermal Imaging allows quick detection of air leakage or inadequate insulation on HVAC equipment. It also pinpoints low resistance heating elements, broken power wires, defective fans and pumps, loose belts, improperly adjusted valves, overloaded circuit breakers or fuses, crimped electrical connections, and other problems that are not visible to the naked eye. This can make it much easier to quickly identify the location of various heat sources in areas where access is limited or in environments with poor lighting.

Digital images are also saved for future reference and analysis. The information gathered during thermal inspections can be used to establish baseline operating conditions when the equipment is new or working correctly, allowing for easy detection of irregularities when they arise in the future.

Thermal Imaging with Digital Photography
Thermal Imaging with Digital Photography

Digital images of thermocouples and other temperature sensing devices allow for numerical assessment of actual temperatures throughout an environment. These can be correlated against theoretical models to establish flow rate or fluid leak detection reports that are both accurate and objective.

Lightning Mechanical offers digital thermal imaging as part of our air conditioning advanced troubleshooting service. It helps us make sure your HVAC solutions maintain a comfortable temperature and that they can replenish oxygen in line with your indoor air quality standards.

What is Digital Thermal Imaging?

Simply put, digital thermal imaging is fast, non-invasive visualization of the invisible heat signatures that are naturally emitted by moving air, equipment, and other objects. It shows relative temperature differences of various air conditioning components within a scene, allowing the viewer to see where areas of high heat concentration exist visually. This process quickly detects hot spots on electrical lines, power transistors, transformers, circuit breakers, pumps, valves, and other equipment.

Thermal Imaging with Digital Photography

The Imaging Process:

When an object is heated to a temperature greater than room temperature (or the ambient air surrounding it), it emits infrared radiation in the form of heat. Digital thermal imaging cameras detect this invisible energy with their highly sensitive detector technologies (microbolometer focal plane arrays) and convert it into an electronic signal processed by the camera's internal computer. The thermal image is then passed to a monitor, where heat sources can be identified as either hot (red-orange), warm (yellow), or cool (blue), depending on their temperature.

Thermal Imaging Use Cases:


Before any service is performed on air conditioning, it often becomes necessary to perform a pre-inspection to make sure that no unexpected hot spots are found before the unit is placed out of service for adjustments or repairs. Since these areas are usually not ordinarily accessible without removing equipment panels, we train service technicians in thermal imaging to scan for problems before doing any work.

In some cases, this may also save them from adding unnecessary parts or labor costs if a problem has already been detected without having to dismantle any heat pumps, plumbing, air duct vents, or other HVAC system components.

Heat Pumps

Heat pumps are an excellent example of when thermal imaging makes equipment troubleshooting fast and easy. Even if the compressor is not running, the cooling fins on its exterior condenser typically radiate heat due to forced air convection or their proximity to other hot objects. Cooling fins that are warm to the touch indicate that some degree of heat rejection is occurring and that the cooler side of the heat pump's heating cycle is still working.

Thermal imaging can also show hot spots in your air conditioning which indicate blocked access ports or areas where insulation may be inadequate. These problems are usually more prevalent on older units than newer ones, but they do occur on equipment of all ages.

Airflow Measurements

Thermal Digital Photography can generate air conditioning airflow and fluid (steam, gas, chemical) leak detection reports. Digital images of airflow patterns within ventilation hoods or other anemometers allow for calculating volumetric airflow rates and directionality. This data can then be used to compare against the known design criteria for a system to detect insufficient or improperly-aligned hoods.

Refrigerant Leak Detection

Leaks within the cooling system of a heat pump typically occur at either the expansion valve or capillary tube. Since these components are usually located inside a coil housing or cabinet, their hot spots cannot be seen with the naked eye. However, if they are visible to thermal imaging, their location can be determined by matching them up with the rest of your air conditioning system's temperatures.

HVAC Engineers often use thermal imaging to find leaks in refrigerant lines by holding the camera up to a section of tubing and moving it around until they detect a hot spot. If the equipment list indicates that the unit is either overcharged or has an undersized recovery cylinder, this can be confirmed by measuring the operating pressure to see if it matches the known design criteria.

Equipment Adjustment

Improperly adjusted or undersized air conditioning controls can also be detected by observing if excessive hot or cool areas are seen in particular zones since this would indicate that airflow rates were either too high or too low for an acceptable HVAC load calculation.

Thermography is also frequently used during the installation and commissioning of HVAC equipment to ensure that it is properly balanced and that airflow rates and temperatures meet design criteria before the unit is placed into service.

Heat exchangers

Leaks in a heat exchanger can lead to serious problems with your HVAC systems if they go undetected for too long. Since the hottest parts of the equipment are typically at its welded joints, focus points for thermal imaging are often located near these areas. When a leak is suspected, the system designer's calculations can be used to calculate the change in temperature across a defective section to determine if it has reached an unacceptable threshold. If not, the area just downstream will give a good idea as to where the leak is located.

Component Inspection

Thermography is also used to inspect the interior surfaces of heat exchangers for other defects such as pitting, corrosion, or erosion. Since these conditions can have a negative impact on HVAC system efficiency, they are typically identified during routine plant tours so that they can be repaired before any significant damage occurs.

Steam Traps

Even though they are usually not found on most HVAC equipment, steam traps can also be inspected with thermal imaging to make sure they are operating properly. Since their heat source is typically a coil of vaporizing liquid, hot spots will only be found when the valve begins to open and allow condensate to flow back into the system. This is normally detected during a walk-thru before the unit begins to produce steam.

Heat Recovery Units

On larger HVAC systems with multiple sources of heat, it may occasionally become necessary to recover waste heat from one source and use it elsewhere to meet plant requirements. Since this is also an energy-efficient approach that can reduce operating costs over time, it has grown in popularity over the years.

These units typically include valves, filters, condensate tanks, and pumps not found on conventional HVAC systems; their paint or insulation can sometimes be damaged by leaks or other damage. This will usually show up as a hot spot that should be investigated to prevent further corrosion or other problems from developing.

Moisture Detection

In addition to finding hot spots, thermal imaging can also detect cold areas if excessive moisture is present. Although this may be difficult in some cases when steam or other fluids are present, it is usually more apparent on the service floor where water-based solutions are used during cleaning operations. Since these areas will show up as cool spots on the image, it is essential to recheck them during each cleaning period.

Environmental Monitoring

When HVAC equipment is located in an unoccupied space, thermal imaging can be used as a continuous monitoring tool since hot or cold spots may indicate that there are problems with natural ventilation or temperature settings. While this requires someone to monitor the equipment around the clock, the benefits of shutting down equipment before it fails are usually well worth the additional costs. Alternatively, thermal cameras can be integrated with your data logging solution to remove the need for physical monitoring.

Indoor Air Quality Monitoring

In most cases, HVAC systems are used to circulate air throughout a building. Since the quality of that air can have an impact on occupant health, some facility managers will use thermal imaging as a continuous monitoring tool for carbon dioxide (CO2) and carbon monoxide (CO). Although other types of equipment such as gas detectors or ionizing smoke detectors can also be used, thermal imaging is usually a reliable precursor in most cases when dangerous gas levels are present and can inform design decisions for natural ventilation or mechanical ventilation assisted by a network of fans.

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We provide thermal imaging services for most homes, businesses, and industrial facilities in the New York City tri-state area.

Areas we serve include:

  • New York
  • New Jersey
  • Northern Maryland
  • Southern Maine
  • Western Pennsylvania
  • Eastern Long Island

Get in touch via email with or to find out how our maintenance and repair services can keep you comfortable this winter.

We also work closely with construction companies to ensure the windows they put in don't let dust or air through. If that sounds like you, call (973) 763-0300. We look forward to working with you.

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