New Technologies in HVAC: What We Know and Where the Industry Is Heading Greg Jourdan, HVAC/R Professor Wenatchee Valley College, Washington 1-2:30, 3-4:30
New Technologies in HVAC: What We Know and Where the Industry Is Heading Session One, 1-2:30 a) High-efficiency heat pumps b) High-efficiency furnaces c) Variable speed ECM motors Session Two, 3-4:30 a) Thermal imaging tools b) Modern test tools for Energy Efficiency c) How HVAC pros can better serve current clients and generate new business.
Session Two Technology Quiz 1. What is the IR term used on a shiny or dull surfaces? 2. What happens to accuracy with IR thermometers when they are close to the object? 3 What is the accuracy of an IR thermometer at 20 ft, with a 10:1 optical resolution? 4. T F A 20-in. X 20-in. filter grille is a good choice for a 4-ton unit 5. T F Low E IR thermometers are better than high E. 6. T F 8 flex duct delivers 200 cfm. 7. T F Infrared is low-level light energy, not visible to the human eye. 8. T F Ducts leakage is typically only 20%. 9. T F Using 0.1-in. wc friction rate on a ductulator will always give me the right size supply duct.
Infrared Single Point IR Thermometers, Thermo-graphy and Modern Test Tools An introduction to the technology
Primary Applications Of Thermal Imaging Maintenance of machinery Building diagnostics Fire fighting Law enforcement and security HVAC Environmental Human and animal medicine Many others
IR Test Tool for Single Point Infrared Thermometry Applications IR temperature measurement is ideal for applications involving: hot surfaces rotating objects electrically live surfaces difficult-to-reach locations speed and relativity of temperature
Infrared Temperature Measurement Infrared is low-level light energy, not visible to the human eye. All objects naturally emit infrared energy. IR thermometers use special optics to measure this invisible energy.
Infrared Thermometry Applications IR temperature measurement is ideal for applications involving: Hot surfaces Rotating objects Electrically live surfaces Difficult-to-reach locations Speed and relativity of temperature
Infrared Temperature Measurement Optical resolution Ratio of the distance from the measured object vs.. the sampling spot size. Examples: 4:1 optical resolution: 4 away from measured object 1 diameter sampling size 10:1 optical resolution: 20 away from measured object 2 diameter sampling size Know your application! An IR device with a 4:1 optical resolution can not effectively be used to measure a diffuser temperature 15 away.
Field of View (FOV) IR Temperature Field of View refers to the target size relative to the IR thermometer s spot size. Ideally, the target surface to be measured should be twice the size of the spot. If the spot size is larger than the surface to be measured, measurement errors are increased.
Infrared Temperature Measurement Emissivity is a numerical value between 0 and 1 which indicates the ability of an object to emit infrared energy. Emissivity is determined primarily by the material from which an object is constructed and its surface finish. Examples: Polished brass: 0.03 Roughly polished copper: 0.07 Oxidized brass: 0.61 Black oxidized copper: 0.78 Black lacquer paint: 0.96
Infrared Temperature Measurement Emissivity Low cost infrared measurement instruments are typically fixed at a 0.95 emissivity. To get an accurate temperature reading, the surface being measured must be close to 0.95 emissivity. A shiny surface can be covered with black paint, electrical tape, magic marker, or any other item which will be less reflective.
Electronic Thermometers can be Point Specific or Image Specific for Predictive Maintenance Non-Destructive Maintenance and Testing Using Thermography This service tech is checking the electric motor for hot spots with a Thermal imaging tool.
Examples of Applications Using the Thermo-imaging Tool Photos courtesy of Fluke
Thermography is: The use of electronic cameras to detect radiant energy or heat. Produces a visual image called a thermogram (or heat picture). Some cameras infer temperature based on the amount of radiation detected. Thermography is a powerful tool for machine and building maintenance.
Thermography is NOT: Heat waves. Infrared photograph Used as a toy.
Primary Applications for Thermal Imagers Maintenance of machinery Building diagnostics Fire fighting Law enforcement and security Environmental Human and animal medicine Many others
Heat and Energy As an object warms up, it radiates more energy, as photons, based on: Temperature. Emissivity. Infrared radiation is electromagnetic radiation, similar to light and radio waves. Wavelengths between 2-15 microns are called thermal infrared radiation.
Heat or Thermal Imaging for a Home 19
Image courtesy D.Southworth Economics: Cost savings* Can reduce Home Fires Half of the electrical failures could be prevented with regular maintenance Unplanned downtime due to equipment failure costs manufacturers up to 3% of their revenue Predictive maintenance can save 8 12% over reactive maintenance * Source: US Federal Energy Management Program 20
Thermography Is non-contact Applies to most all types of equipment and conditions Is obtained without disturbing production Quickly identifies specific locations Detect problems before failure Can scan large areas quickly 21
Reflection, Absorption and Transmission The Basics of IR Technology When IR radiation strikes an object surface, it reads the radiated energy. 22
What is Thermography? Thermography is the measurement of temperature remotely to indicate equipment health and assigning a color based on the temperature. Electrical equipment Electrical circuits Mechanical equipment Heating/cooling equipment Building envelope Electronic Medical Other 23
Thermal Applications Building Envelope and Roof Leaking Ducts Electrical HVAC Equipment Motors 24
Electrical systems Commonly inspected components Power Panels Fuse boxes Cables & connections Relays/Switches Insulators Capacitors Substations Circuit breakers Controllers Transformers Motors Typical reasons for temperature hotspots or deviations Too Heavy loads Unbalanced loads Harmonics (3rd harmonic current in Neutral) Overloaded systems/excessive current Loose or corroded connections increased resistance in the circuit (typically one side of components heats up) Insulation failure Component failure Wiring mistakes Underspecified components (like fuses) would heat up on both side of the fuse
Conditions for inspection Direct view open enclosure doors, when possible You cannot see through enclosure doors! Note even small temperature differences when conditions suggest they may be important Understand present and future loading conditions Inspect with highest possible load 26
Two breakers are 35 F above ambient 27
Hot Phase 28
Hot Fuse Connections 29
Hot connection Corrosion or bad fuse? 30
Bad Connections 31
Inspect lug connections and also look for subtle patterns that may be caused by internal contacts or connections to the bus 32
Quickly locate high resistance connections causing excessive heat on conductors 33
Identify a possible phase imbalance or high resistance connection Note the increase in temperature on this wire 34
Electro-mechanical Commonly inspected components Motors Pumps Heat exchangers Compressors Evaporators/Condensers Typical reasons for temperature hotspots or deviations Bad cooling- due to reduced airflow PQ problems like unbalance, overload or 5th harmonic (voltage) will cause heat dissipation Bad alignment Insulation problems with motor windings Bearing problems lubrication, wear, etc.
Mechanical systems Commonly inspected components Pumps Refrigeration Coils Bearings Gearboxes Drive belts Typical reasons for temperature hotspots or deviations Friction due to wear, misalignment or inadequate lubrication
Moto rs Uneven heating in an electrical motor will reduce the life and efficiency of the motor if not properly addressed For each 10ºC (18ºF) rise over maximum rated temperature, approximately ½ the life of a motor is lost due to insulation failure! 37
Find loose or misaligned belts 38
Low Flow and Lack of Heat Transfer 39
Find Problems with Steam Traps Steam traps 40