Some problems with HVACR systems seem to defy diagnosis. The key components (compressors, heat exchangers, fans, etc.) and interconnecting pipes and ducts of most systems are hidden from view - behind walls, or in hard-to-access crawl spaces - so it can be difficult or virtually impossible for a technician to quickly determine why a system failed, or is performing poorly.
In many cases, disassembling some or all of the system (often requiring the destruction of walls or ceilings) is a necessary step of a diagnostic or maintenance inspection. But even when it’s a last resort, disassembling and reassembling a system and repairing or replacing drywall takes considerable time. And time is money, both to contractors and their customers.
OPTIC SOLUTIONFortunately, there are newer, more elegant ways to reduce the traditionally high cost of pinpointing hidden problems. It takes the form of a new breed of inexpensive, yet powerful, video inspection systems that enable HVACR contractors and techs to “see through” walls, floors, or ceilings, thus eliminating the need to disassemble systems to isolate the cause of their failure or poor performance.
The heart of any video inspection system suitable for HVACR maintenance is the camera scope. The scope utilizes a probe that is thin enough to fit through a small aperture in the equipment or in a wall, long enough (optionally up to 98 feet) to reach otherwise inaccessible locations, and flexible enough to allow a technician to repeatedly reposition its business end and hold it in place.
At the business end there is a tiny color video camera with multiple LED lights (insulated from water, oil, and dust) to illuminate the area of interest. At the other end of the probe is the camera scope with a color LCD monitor like that found on digital cameras and camcorders.
The features on the camera scope systems progress in sophistication as the price of the system increases. The least-expensive camera scopes have a color monitor and are designed for real-time imaging. More advanced models have larger LCD screens and internal memory cards. They can record and store still images, videos, and sound.
They also have the ability to download files to a Mac or PC, or view them on an external monitor. Wireless systems allow technicians to operate the probe remotely, from a distance of up to 100 feet, making inspections of inaccessible areas a lot easier.
APPLICATIONSThe range of HVACR maintenance tasks that a video inspection system can help contractors perform more quickly and safely seems to be limited only by their imagination. They include:
• Checking heat exchanger/condenser tubes and fan belts and blades for breaks and cracks.
• Inspecting the interior of ducts and pipes. Among the common problems that can be pinpointed are leaks, areas of corrosion, dust buildup, dry rot, plugged drainage holes, and the presence of pests (like termites) and foreign objects. Leaky ducts are particularly insidious because they show no symptoms but nonetheless force HVAC systems to work harder than necessary, raising their end users’ energy costs.
• Checking for mold, which is increasingly problematic in newer buildings that are so airtight they are excellent moisture traps. Moisture, when trapped beneath or between surfaces, provides an ideal environment for the growth of mold. Pipe chases and utility tunnels are especially susceptible to hidden mold growth, as are condensate drain pans inside AHUs, porous thermal or acoustic liners inside ductwork, and roofing materials above ceiling tiles.
• Detecting corrosion on the bottom of LP gas tanks.
• Reading part numbers, serial numbers, and last inspection dates stamped on the hard-to-reach bottoms of components, such as oil burners.
• Inspecting furnaces, heater burners, and injectors. And,
• Locating existing electrical wiring, water pipes, and structures before an installation begins.
According to Mike Buscemi, a salesman with the industrial distributor Johnstone Supply in Farmingdale, N.Y. (who has sold dozens of the Seeker™ video inspection systems from New York-based General Tools & Instruments Co.), several of his contractor customers now routinely use a video inspection system to document their installations from start to finish. Videos and images not only prove to customers and regulators that a job was done right, they can also serve as evidence of the need for further work. The idea is similar to a dentist using X-rays to show patients tooth decay and other problems that need addressing.