Utilities Manager: Using Thermal Imagers In Your Energy-Efficiency Program
Kathy | February 1, 2008
Versatile, feature-rich and affordable new products can help you quickly identify potential problem areas and begin analysis in the field.
If you’re looking for ways to save energy within your facility, consider conducting a thermal inspection. Thermal inspections can quickly identify energy inefficiencies in the building envelope (heating and cooling losses) and electro-mechanical operations. Furthermore, now that thermal imagers cost less than most capital expense limits, facilities can conduct energy-effi- ciency inspections themselves with the same tool they would use for electro-mechanical troubleshooting. Fluke Corporation’s new thermal imaging products offer just that type of versatility.
The affordable new Fluke Ti10 Thermal Imager is a case in point. It incorporates a high-resolution, fully radiometric screen (every pixel in the picture has an associated temperature) that displays IR-Fusion® blended thermal-plus-digital pictures. This patent-pending technology integrates infrared and visual (visible light) images in full screen or picture-in-picture views for enhanced problem detection and analysis. The ability to scroll through the different viewing modes helps users recognize image details and identify problem areas better.
According to Fluke, IR-Fusion is especially useful in energy inspection work. With the blended digital-thermal image it provides, users can pinpoint the location of a leak on a wall exactly. With a thermal-only image, everything looks the same.
The other advancement with Fluke’s new imagers is that they’re much easier to use than in the past. The on-screen menus make sense, the options are simple and a user can just point, focus and shoot. That means facilities staff don’t have to specialize in thermography or go through extensive training. They also don’t have to worry about breaking these products—the rugged new models can drop six feet and still keep working.
Building envelope inspections
The HVAC system is often one of the biggest energy consumers within a facility. And the irony is that much of the conditioned air often is leaked right out the building, through the roof, walls, ducts, pipes, etc.
Thermal imagers detect anomalies and variances in surface temperatures that may indicate heat loss or gain. The key with building envelope inspection is that the degree of variance may be very small—perhaps just one or two degrees, depending on the scope of the problem. To spot such small changes, it’s important to select a thermal imager with high thermal sensitivity. (HVAC professionals in particular may want to consider Fluke’s new TiR and TiR1 models with IR-Fusion capability incorporated in both the camera and software. Designed with building diagnostics in mind, they offer just the type of high thermal sensitivity required for this crucial application.)
Building envelope inspection points include all insulation areas (walls, pipes, ducts, boiler, furnace, process equipment, water heater), roofs, windows, doors and construction joints.
- Scan during a heating or cooling season, when the outside temperature is at least four degrees different from inside.
- Focus on walls that separate conditioned from unconditioned spaces, and on the top and bottom of conditioned spaces.
- Large gaps often exist around pipes, lighting fixtures, and utility entrances.
- Addressing major losses such as roof leaks offers fastest payback.
High-resistance, overloaded and imbalanced electrical connections and overheating equipment all have something in common: They’re using too much energy. You’ll want to scan your electrical system and your largest power-consuming mechanical devices (motors, pumps, compressors, etc.) and look for changes in temperature and unusual hotspots.
Electrical inspection points include panels, controls and the disconnects, contactors and relays within them.
Mechanical inspection points include gearbox, bearings, sheaves/belts and overall casing operating temperature compared to nameplate data.
- Inspect both electrical and mechanical equipment under normal load/operating conditions.
- If you detect a hotspot, investigate with other tools (multimeter, power quality, lubrication, etc.) to evaluate operational health.
- In most cases with old equipment (lighting and HVAC systems, motors, drives), the quickest route to the biggest energy savings is upgrading to new, highefficiency models.
Other inspections: steam systems
Plants that use steam can use a thermal imager to periodically check their trap and line temperatures for inefficiencies. If temperature is low in the steam pipe, trap and condensate return, the trap may be stuck closed. If temperature is high, the trap may be stuck open. If temperature is high in the pipe and trap, and slightly lower in the condensate return, the trap is probably operating properly.