Inficon Holding Ag · SIX:IFCN
Inficon — National HVACR Educators & Trainers Conference 2019
46 slides from Inficon's conference presentation, March 2019
Slide 1: Leak Detection Technologies and Best Practices
Leak Detection Technologies and Best Practices National HVACR Educators & Trainers Conference March 2019
Slide 2: Bob Belvick
Bob Belvick Product Manager, Service Tools Leak Detection
Slide 3: Overview
Overview Why we leak check Refrigerant characteristics and types Leak detection methods Electronic leak detection sensor technologies Tips and best practices Predicting the future
Slide 4: Why we Leak Check
Why we Leak Check @INFICON
Slide 5: Why repair leaks?
Why repair leaks? Save the planet • Reduce global warming potential (GWP) • Reduce ozone depletion potential (ODP) Regulations • Phase-out of CFCs and HFCs • EU regulations say you cannot add refrigerant to a leaky system Leaks are expensive • Especially new refrigerants • Phase-out refrigerants ris
Slide 6: Refrigerant Characteristics and Types
Refrigerant Characteristics and Types
Slide 7: Important Refrigerant Characteristics
Important Refrigerant Characteristics Ozone Depletion Potential (ODP) • Relative degradation of the ozone layer • Compared to R11 (ODP of 1, very bad) • Lower number is better Global Warming Potential (GWP) • Energy absorbed by the atmosphere from emissions of 1 ton of gas • Compared to CO2 (GWP of
Slide 8: Important Refrigerant Characteristics
Important Refrigerant Characteristics ASHRAE 34 Safety Group Classification • Letter indicates toxicity (A is better) • Number indicates flammability (low number is better)
Slide 9: Important Refrigerant Characteristics
Important Refrigerant Characteristics More on Flammability • A3 refrigerants include high flammable gas like propane • Use an intrinsically safe leak detector and other equipment • Do not vent into enclosed area (can explode or start fire) • System charges are usually small (currently up to 150g (5
Slide 10: Refrigerant Types
Refrigerant Types CFC (Chlorofluorocarbon) • Contain chlorine • R12, R11, R13, R113, R114 • High ODP and GWP • Must be recovered HCFC (Hydrochlorofluorocarbon) • Contain chlorine • R22, R123, R124, R141b, R502, R503 • Lower ODP and GWP than CFCs • Must be recovered
Slide 11: Refrigerant Types
Refrigerant Types HFC (Hydrofluorocarbon) • No chlorine • R134a, R125, R23, R410a, R404a, R32* • No ODP and lower GWP • Must be recovered HFO (Hydrofluoro-olefin) • No chlorine • R1234ze, R1234yf, R454a/b • No ODP and almost no GWP • 1234yf has 335 times lower GWP than 134a • Semi flammable – A2L re
Slide 12: Refrigerant Types
Refrigerant Types Natural HC (Hydrocarbon) • Highly flammable – A3 refrigerant • Small charges • R441a (mix) 100yr GWP – 3.6 • R290 (propane) 100yr GWP – 3.3 • R600a (isobutane) 100yr GWP – 3 • No ODP • Can be vented (not in an enclosed area)
Slide 13: Refrigerant Types
Refrigerant Types Natural Ammonia (R717) • No ODP, GWP = 0 • B2L classification • Semi flammable • Toxic • Can be vented (not in an enclosed area) CO2 (Carbon dioxide, R744) • No ODP, 100yr GWP = 1 (CO2 is the standard for GWP) • High pressure • Can be vented (not in an enclosed area)
Slide 14: Leak Detection Methods
Leak Detection Methods @INFICON
Slide 15: Leak Detection Methods: Halide Torch
Leak Detection Methods Halide Torch An open flame changes color if chlorine- based refrigerant is present Advantages • Simple • Inexpensive Disadvantages • Poor sensitivity (~0.5 oz. [14 g] /year) • Reaction based on chlorine • Won’t pick up HFCs • Fire Hazard • Health Hazard
Slide 16: Leak Detection Methods: Soap Bubbles
Leak Detection Methods Soap Bubbles Advantages • Inexpensive • Simple Disadvantages • Can mask leaks from other detection methods • Slow and not very sensitive • 0.25 oz. (7 g) /year leak takes 10 – 15 min. to make 1 bubble • Electronic leak detector takes less than 1 second
Slide 17: Leak Detection Methods: Fluorescent Dye
Leak Detection Methods Fluorescent Dye Advantages • Can find multiple leaks at once • Good for quick leak checks • If you keep dye in the system Disadvantages • Must be able to see the leak • Takes time for dye to cycle through system • Not feasible with very large systems • Hard to clean • Difficul
Slide 18: Leak Detection Methods: Forming Gas
Leak Detection Methods Forming Gas 95% nitrogen / 5% hydrogen, AKA Tracer Gas • A mixture of nitrogen and hydrogen is added to a leaky system • A combustible gas leak detector is used to detect the hydrogen in the gas • Not considered flammable
Slide 19: Leak Detection Methods: Forming Gas
Leak Detection Methods Forming Gas 95% Nitrogen / 5% Hydrogen Advantages • Safe, non-flammable • Inexpensive alternative to helium or refrigerant • Environmentally safe Disadvantages • Must have HC leak detector • Time consuming • Recover refrigerant, charge forming gas, leak check, recover forming
Slide 20: Leak Detection Methods: Electronic Leak Detectors
Leak Detection Methods Electronic Leak Detectors • Ultrasonic • Corona Suppression • Surface Reaction • Heated Diode • Infrared
Slide 21: Electronics Leak Detector Sensor Technologies
Electronics Leak Detector Sensor Technologies
Slide 22: Sensor Technologies: Ultrasonic Leak Detection
Sensor Technologies Ultrasonic Leak Detection • A specially tuned microphone that “listens” for the sound of a leak • Leaks emit a sound at a frequency higher than we can hear (ultrasonic)
Slide 23: Sensor Technologies: Ultrasonic Leak Detection
Sensor Technologies Ultrasonic Leak Detection Advantages • Can be used on any gas (as long as there is pressure or vacuum) • Effective on pressure or vacuum leaks • No consumables (filters, sensors) • Many other applications • Car tires • Pneumatic lines • Bearings Disadvantages • Difficult to pinpo
Slide 24: Sensor Technologies: Corona Suppression
Sensor Technologies Corona Suppression • A static charge between two electrodes creates a current • An insulating gas (like refrigerant) reduces the current in the sensor, causing an alarm
Slide 25: Sensor Technologies: Corona Suppression
Sensor Technologies Corona Suppression Advantages • Sensitive to multiple gases • Inexpensive to manufacture Disadvantages • Cross sensitivity • Humidity will give false alarms • Dirt, oil, grease will shorten sensor life
Slide 26: Sensor Technologies: Surface Reaction
Sensor Technologies Surface Reaction • An electrical circuit is masked to a metal oxide substrate. • Metal oxide attracts oxygen in clean air • When the sensor is exposed to reducing gases (like refrigerant), the oxygen reacts with it and burns off • This reaction increases the current, causing an a
Slide 27: Sensor Technologies: Surface Reaction
Sensor Technologies Surface Reaction Advantages • Rugged Construction • Low power consumption • Inexpensive to manufacture • Can detect refrigerant and combustible gases Disadvantages • Cross sensitivity • Low sensitivity to HFCs • Longer reaction/recovery times
Slide 28: Sensor Technologies: Heated Diode
Sensor Technologies Heated Diode • A coiled wire coated with ceramic material is heated to 1400° F • The heated sensor breaks apart refrigerant molecules, leaving chlorine and fluorine ions • Chlorine and fluorine ions create a current that causes an alarm
Slide 29: Sensor Technologies: Heated Diode
Sensor Technologies Heated Diode Advantages • Halogen selective • Resulting in fewer false alarms • High sensitivity to chlorine-based refrigerants • Quick reaction and recovery Disadvantages • Expensive to manufacture • Sensitivity to HFCs is not as good as HCFC or CFC refrigerants • Short sensor l
Slide 30: Sensor Technologies: Infrared Absorption
Sensor Technologies Infrared Absorption • Infrared light is shone down a tube to a detector • A filter only allows wavelengths of light absorbed by refrigerants into the tube • When refrigerant is present, it absorbs the light and reduces the amount of light received by the detector, causing an alar
Slide 31: Sensor Technologies: Infrared Absorption
Sensor Technologies Infrared Absorption Advantages • Typically the most sensitive • Selective to refrigerant compounds • Fewer cross-sensitivities • Allows for quantitative measurements • Quick reaction and recovery time • Longer sensor life, 1,000+ hours • Sensitivity does not degrade over time Dis
Slide 32: Cloud Hunting
Cloud Hunting What is it? • Use a leak detector with a numeric readout showing background concentration • Follow the number to the most concentrated area (the cloud) • Like a game of hot and cold • Once you find this area, you can pinpoint the leak • Less confusing than when a regular leak detector
Slide 33: Tips and Best Practices
Tips and Best Practices @INFICON
Slide 34: Tips/Best Practices
Tips/Best Practices Use a combination of techniques/equipment • Helps verify your first technique is working • Some techniques are better for a certain job Understand the problem • How much refrigerant has leaked out? • How long has it been leaking? • Is there refrigerant still in the system? • What
Slide 35: Tips/Best Practices
Tips/Best Practices Refrigerant “drips” out of the leak • Gross leak check by starting at the low point of the system • To pinpoint, go from high spots to low spots Check most common leak sites first • Valves • Fittings • Condenser • Evaporator
Slide 36: Tips for Electronic Detectors
Tips for Electronic Detectors Know the environment Outdoors • Wind will affect readings since it “blows away” the refrigerant. • Leak detectors are sampling for the refrigerant • Block wind whenever possible Indoors • Background refrigerant accumulates over time • Refrigerant accumulates faster in s
Slide 37: Tips for Electronic Detectors
Tips for Electronic Detectors Cross contaminants can cause false alarms • Cleaners • Soap bubbles • Can also temporarily clog leaks • Pipe sealers • Alcohol • Some materials can outgas • Some insulations have chemical properties similar to refrigerants
Slide 38: Tips for Electronic Detectors
Tips for Electronic Detectors Auto zero vs. manual zero Auto zero Unit will automatically zero to background every 7-10 seconds • Once zeroed to background, will only alarm with higher concentration • Put the probe in clean air to reset zero Manual zero User zeros to background by pushing a button U
Slide 39: Tips for Electronic Detectors
Tips for Electronic Detectors Know your sensor type • Corona suppression • Heated sensor/surface reaction/tin-oxide • Heated diode • Infrared What are the advantages and shortcomings of yours? For example: • Surface reaction • Many cross sensitivities • Heated diode • Great for R22 but not great for
Slide 40: Tips for Electronic Detectors
Tips for Electronic Detectors Perform proper maintenance Sensor • Check with leak standard, sample leak, or returned tank • For heated diode, best to start fresh each season Batteries • When in doubt, replace the battery (alkaline) • Rechargeable batteries can go bad too Filters • Dirty filters redu
Slide 41: Large Leaks: How to attack it?
Large Leaks: How to attack it? 1. Visual inspection • Look for oil, frozen pipes, obvious signs 2. Gross leak check from low to high to determine area • HFC / HCFC refrigerants are heavier than air 3. Remove background refrigerant (clear the air) 4. If quiet environment, start with Ultrasonic detect
Slide 42: Small Leaks: How to attack it?
Small Leaks: How to attack it? 1. Visual inspection 2. Remove background refrigerant 3. Use Electronic detector • Pinpoint leak checking from high to low • Move slowly 1 to 2 inch per second (2 to 4 cm) to find small leaks • If unit alarms, pull away from leak and then double check to verify
Slide 43: Predicting the Future
Predicting the Future @INFICON
Slide 44: Future Expectations
Future Expectations More natural refrigerants CO2 • All new refrigeration installations in Europe • Increased usage in automotive Flammables • Refrigerators • Automotive • Increased limits mean larger coolers • Recovery machines? A2Ls • 1234yf in automotive • R32 in China
Slide 45: Future Expectations
Future Expectations Where are leak detectors going? One detector for all gases • Many customers are asking for one detector for everything • HFCs, HFOs, natural refrigerants Cloud hunting and pinpointing in one • PPM display • Pinpoint mode Example: INFICON D-TEK Stratus® • Interchangeable sensors f
Slide 46: Questions?
Questions?
Inficon — National HVACR Educators & Trainers Conference 2019 on 6ix