2. What does ozone in the stratosphere above the earth consist of? The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth's surface, in the stratosphere. What does ozone depletion potential (or ODP) measure? d. R-502. Which of the following refrigerants have an ozone depletion potential of more than zero? The purchaser is or employs a Section 608 certified technician. Maybe HFOs are the perfect refrigerant, but I have a feeling well be going through this again and sooner rather than later. HFOs are distinguished from HFCs by being derivatives of olefins rather than alkanes (paraffins). Lets keep everyone on their toes. d. HFOs, Which of the following refrigerants has the lowest ozone depletion potential? Blowing off units. What is the name of the EPA's program that identifies refrigerants with lower overall risks to human health and the environment? The R-12 and R-22 CFCs contained high amounts of Chlorine and it was found that Chlorine damaged the O-Zone. They are toxic to plants and animals at low doses. Which of the following refrigerants is an HFO? Find and create gamified quizzes, lessons, presentations, and flashcards for students, employees, and everyone else. See author's posts. c. Measurement of HCFCs in air samples from the stratosphere. a. A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to leak check the appliance. Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully chargedappliance to leak check the appliance. A B. Solstice N13 is designed to replace R134a and offers a GWP that is 60 percent lower than the GWP of R134a. If you are in the EU youve already been dealing with them for years and if you are in the states get ready! What are the characteristics of hydrofluoroolefins (HFOs)? Why are HFO refrigerants less flammable than hydrocarbon refrigerants? In Lack's study, the effect of weather on the size of the finchs beak is an example of A refillable cylinder must not be filled above what percent of its capacity by weight: Under what conditions may you use a disposable cylinder to recover refrigerant? Servicing of existing vehicles using HFC-134a with HFC-134a will not be impacted and will continue to be allowed. Now, there are a variety of reasons for the price being so high but I am only going to go into a couple of them. What does a Section 608 certification allow a technician to do? Which word applies to the process that returns refrigerant to new product specifications and that requires chemical analysis? 1234YFs main opponent is Daimler out of Germany. Removing refrigerant. Which element of a CFC or HCFC molecule causes ozone depletion? Ozone is "good up high, bad nearby." Which type of refrigerant is the most harmful to stratospheric ozone? In what state does the refrigerant leave the condenser? (Table 2 lists some known CFC, HCFC, HFC, HFO, HC, and natural refrigerants with their safety classifications and boiling points at atmospheric pressure for comparison purposes.). OEMs must keep records of the tests performed for a minimum period of three years demonstrating that CO2 refrigerant levels do not exceed the STEL of 30,000 ppm averaged over 15 minutes in the passenger free space, and the ceiling limit of 40,000 ppm in the breathing zone. highly fluorinated toxic chemicals. Share sensitive information only on official, secure websites. So, the CFCs were phased out and replaced with the HFCs which had a substantially lower amount of Chlorine compared to its predecessors. However, because of these refrigerants low boiling points, safety precautions must be taken. Suppose you have an unknown clear substance immersed in water, and you wish to identify it by finding its index of refraction. By the 1995 model year, all new vehicles sold in the United States with air conditioners used HFC-134a refrigerant. Which element in a CFC or HCFC molecule causes ozone depletion? Self-contained breathing apparatus (SCBA) or leave the area is required. (A2 means low flammability and low toxicity.) d. They contain carbon. Ozone depletion in the stratosphere is what type of problem? This gives these refrigerants low GWP, and is the primary reason for the increased interest in these fluids. In 2012, automobile manufacturers began the transition to new, climate-friendly alternative refrigerants. Even though everyone has just switched over to R-410A in 2010 it looks like its days are already numbered. Similar tests of the current R134a refrigerant did not result in ignition. Source. For many years, small percentages of HCs have been used in many HCFC- and HFC-based refrigerant blends in the U.S. to assist in oil return to the compressor. Top 5 Reasons Why You Should Buy Refrigerant in Bulk. A leak trace gas. Also, oil changes may be needed with R-32. Recover all remaining refrigerant, render the cylinders useless and recycle the metal. Refrigerant systems should be designed to comply with applicable building and fire codes. The following flammable characteristics of HFOs are reviewed, including the lower flammability limit, upper flammability limit, burning velocity, minimum ignition energy, hot surface ignition. d. R-124. Servicing existing R-22 systems. The development of MVAC systems using lower-GWP refrigerants has been encouraged by MVAC refrigerant requirements in Europe, where the EU Directive on Mobile Air Conditioning (MAC Directive) mandates transition to a refrigerant with a GWP below 150 by January 1, 2017, and in the United States by the availability of credits under the MY 2017-2025Light-Duty Greenhouse (LD GHG) Rule (77 FR 62624, October 15, 2012). d. R-12, Which of the following is a HFC refrigerant? Significant New Alternatives Policy (SNAP) program, the refrigeration and air conditioning sector, Choosing and Using a Retrofit Refrigerants for a CFC-12 Motor Vehicle Air Conditioner, listed as unacceptable for use in new and retrofit MVAC systems, July 2015 final rule under SNAP (July 20, 2015, 80 FR 42870, EU Directive on Mobile Air Conditioning (MAC Directive), Light-Duty Greenhouse (LD GHG) Rule (77 FR 62624, October 15, 2012), new climate-friendly motor vehicle air conditioning refrigerants, Ozone depleting refrigerant with a GWP of 10,900. d. Satellite measurements of light passing through the atmosphere. c. be labeled Have you had more homeowners buying heat pumps due to the IRA's 25C tax credit? The ability of a substance to destroy ozone in the stratosphere. Daimler is still against the HFO and is pushing for a new Carbon Dioxide refrigerant alternative. How do refrigerant blends leak from a system? They are no different than HFCs.B. Use of the ozone-depleting refrigerant, chlorofluorocarbon (CFC)-12, in new motor vehicle air conditioning (MVAC) systems ended in the mid-1990s in the United States. measure the onboard fuel only in liters, which they reported as 7682L7682 \mathrm{~L}7682L. Thus, to determine how much fuel was on board and how much additional fuel was needed, the flight crew asked the ground crew for the conversion factor from liters to kilograms of fuel. HFO-1234yf is a low-GWP replacement for R-134a intended for use in mobile air conditioning (MAC) systems in the automotive industry. a. Discuss the importance of the placenta in the development of a healthy fetus. They must be recovered before opening or disposing of appliances. a. R-600a and R-441A Which of the following is NO a recommended safety practice when operating refrigerant recovery or recycling equipment? They contain Fluorine. In the new real-life test scenario, the refrigerant is dynamically dispersed at high pressure near to hot components of the test vehicles exhaust system. Local Helium, Carbon, Fluorine, & Chlorine Secondly, the majority of all the patents on HFOs, including 1234YF, are held by two companies DuPont and HoneyWell. d. Exemptions granted under the Montreal Protocol. c. 100,000,000 molecules 4. It provides . d. None. What unit does a compound pressure gauge for the low side of the system measure pressure in? There has been talk about bringing back Carbon Dioxide refrigerants but at this point no one really knows what the future holds. HFOs have a higher minimum ignition energy, and a slower burning velocity compared to hydrocarbons. b. Hydrogen, Chlorine, Ferrite, & Carbon in kilograms because Canada had recently switched to the metric system; What is not a violation of the refrigerant management regulations under the Clean Air Act? High discharge temperatures can affect system performance and durability in hot climates. They must be recovered before opening or disposing of appliances. Many refrigerants in the HFO class are inherently stable chemically and inert, non toxic, and non-flammable or mildly flammable. Manufacture's often color code the exterior of gauges. Which of the following is a HFC refrigerant? Which of the following refrigerants has the lowest ozone depletion potential? CCl 3 F as CFC-11). Which of the following refrigerants contains chlorine? How about $90 for your 410A? Medical Information Search The rise in the amount of chlorine measured in the stratosphere matches the rise in ODS emissions over the same period Why are some of the hydrofluoroolefins classified as A2L? An international treaty that addresses ozone-depleting substances and their alternatives.B. even considering that mildly flammable refrigerants are difficult to ignite and propagate the combustion, it is important to understand that, when combusted, the released products of combustion can be . The ambient temperature Why are HFO refrigerants less flammable than hydrocarbon refrigerants? Thus, Edition 7.0 of this standard should facilitate the use of A3 refrigerants with respect to Edition 6.0. This will still make an impact, but it will be minimal to the 134a switch. Measurement of chlorine in air samples from the lower atmosphere. What is the Montreal Protocol? What evidence demonstrates that chlorine in the stratosphere is primarily from man-made chemicals rather than from natural sources such as volcanos? Which of the following refrigerants has the lowest global warming potential? Just as Honeywell has begun producing new HFO refrigerants DuPont is doing the same. EN60335-2-40:2003 Household & similar electrical appliances - Particular . Purchase or handle controlled refrigerants. b. Rewiring an external electrical circuit. Identify several substances found in blood plasma. a. R-134a Because hospitals and drug makers rely on air-conditioning to reduce infections and on refrigeration to manufacture and store life-saving medications including COVID-19 vaccines, for example . What is the state of refrigerant entering the compressor of a refrigeration system? a. R-22 Distributors must verify which of the following before they can sell HFC or HCFC refrigerant? Non-ozone depleting, and have high global warming potentials.B. However, refrigerant blends containing small amounts of HC refrigerants are not flammable. (R-410A, R-404A, & R-134A are excluded from this.) It can be used in both air- and water-cooled chillers in supermarkets and commercial buildings. A printable brochure is available for new climate-friendly motor vehicle air conditioning refrigerants. This is because the HC refrigerant constitutes only a small percentage (less than 3 percent) of the total refrigerant blend. d. R-32 They have high ozone See Details 4.The Professor's Lesson on HFO, HC Refrigerants - ACHR News Author: www.achrnews.com Post date: 30 yesterday Rating: 4 (827 reviews) Highest rating: 3 Low rated: 2 Summary: world example will keep you from such a sloppy habit. Browse over 1 million classes created by top students, professors, publishers, and experts. Which of the following is not a violation of the refrigerant management regulations under the Clean Air Act? b. R-123 b. Propane cylinders for grilling contain impurities that can damage refrigerant equipment. Which refrigerant depletes the ozone layer? Describe the mechanism of a heartbeat, mentioning all the factors that account for this repetitive process. Which of the following is NOT a refrigerant as it is used in Section 608 of the Clean Air Act?A. b. Request a replacement from their certifying organization. One example being the 134a alternative, 1234YF, which is 335 times lower on the global warming potential scale and only four times higher than standard carbon dioxide. Which of the following refrigerants have an ozone depletion potential of more than zero? How should refrigerant blends be charged? c. Ultraviolet radiation from the sun. The 6-kg cylinder is released from rest and falls on the spring, which has been initially precompressed 50 mm by the light strap and restraining wires. Plant and animal life, agriculture, and materials like plastics and paints are also affected. . Which type of refrigerant has the highest ozone depletion potential? The use of CO2 in MVAC systems must adhere to the standard conditions identified in SAE Standard J639 (EPA 2012b). Ammonia, carbon dioxide and hydrocarbons, sold as refrigerants, are manufactured in large chemical plants. b. R-744 The Significant New Alternatives Policy (SNAP) Program. c. Increased rates of skin cancer in humans What is the name of the EPA's program that identifies refrigerants with lower overall risks to human health and the environment? HCs, like HCFC and HFC refrigerants, have boiling points that are desirable for refrigeration and/or air conditioning applications. This helps us keep compliant and prevents any and all future headaches for you or your company down the road. Allow the Tech's company to determine the amount recovered for record keeping purposes. c. Replacing a component. . R-1234yf is still rated as an A2L refrigerant from ASHRAE. Refrigerants for lowering the GWP Ammonia (NH) Carbon dioxide (CO) Hydrocarbons The refrigerant landscape Refrigerants from a Danfoss perspective HFC phase down By visiting this website, certain cookies have already been set, which you may delete and block. ** d. All of the listed are correct. b. Non-ozone depleting and have low globalwarming potentials. What other factors are involved in blood flow? With the gas ballast open.B. The size of the equipment being evacuated Uses for these three HC refrigerants include new stand-alone retail refrigerators. As we mentioned above, flammability is the main risk when working with hydrocarbon refrigerants. . d. The brand of micron gauge used Anticipating the Increased and, even today, breweries. HFO refrigerants are actually unsaturated HFC refrigerants and are widely recognized as the next generation of refrigerants because of their environmental friendliness, cost-effectiveness, and great energy efficiencies. Refrigerants emitted when connecting or disconnecting low loss hoses to charge or service anappliance. However, neither ethane nor methane is used as a stand-alone HC refrigerant today in the U.S. HC refrigerants do contribute to global warming, but their GWP is very low when compared to CFC, HCFC, and HFC refrigerants (See Table 1). They are prohibited for use in the u.s. D. They have ozone depleting potentials, and have low global warming potentials. c. Measurement of HCFCs in air samples from the stratosphere. Many European and some U.S. car manufacturers are currently using HFO-1234yf for mobile air conditioning applications. Class A rating on toxicity signifies refrigerants for which toxicity has not been identified at concentrations of less than or equal to four-hundred parts per million. R-134ad. c. Samples of air taken from the stratosphere over erupting volcanoes show that volcanoes contribute a small quantity of chlorine to the stratosphere compared to CFCs and HCFCs. A large cylindrical bucket of base area A is filled with water. They do not dissolve in water or easily break down in the atmosphere. the use of hydrocarbons as refrigerants. c. The Approved ASHRAE List(AAL) d. Carbon Dioxide, HCFC refrigerants contain which of the following? Throughout your physics course, your Are you used to paying around $100 for your 134a cylinders? The system may be leaking.D. Summary: Why are some hydrofluoroolefins {HFOs) classified as A2L? c. The amount of moisture in the system R32 in its pure form is classified as A2. They have ozone depleting potentials, and have low global warming potentials. A non-ozone depleting substance used in a refrigerator or freezer.C. AllSponsored Content is supplied by the advertising company. ** d. The brand of micron gauge used. c. R-22 They contain Fluorine. You will be required to provide your certificate number or declare the item will be resold to an EPA certified technician on certain types of Refrigerant. What is the Montreal Protocol? A. Fluorine makes HFO refrigerants less flammable than hydrocarbon refrigerants, which are highly flammable. With the vacuum pump operating.C. At uneven rates die to different vapor pressures. They did multiple tests in 2012 and found troubling results: Daimler carried out a series of additional tests on the new refrigerant as part of a new real-life test scenario developed in-house which goes above and beyond the legally prescribed requirements. Acceptable, subject to use conditions, for new vehicles only (June 12, 2008, 73 FR 33304), Moderately flammable (ASHRAE A2), but can be used safely, May be pursued by automobile manufacturers in the future, Engineering strategies and/or devices shall be incorporated into the system such that foreseeable leaks into the passenger compartment do not result in R-152a concentrations of 3.7% v/v or above in any part of the free space1 inside the passenger compartment for more than 15 seconds when the car ignition is on, Manufacturers must adhere to all the safety requirements listed in the SAE Standard J639, including unique fittings and a flammable refrigerant warning label as well as SAE Standard J2773, Refrigerant Guidelines for Safety and Risk Analysis for Use in Mobile Air Conditioning Systems.. What are the characteristics of hydrofluoroolefins (HFOs)?A. Adopting natural refrigerant-based cooling in India: The road ahead Summary Despite this, incremental progress has been made through two important actions that have India's third refrigerant transition, the phasedown contributed to favourable conditions for alternative of high global warming potential (GWP) cooling technologies. b. R-115 Brainscape helps you realize your greatest personal and professional ambitions through strong habits and hyper-efficient studying. A link to the WikiPedia article on the first HFO on the market, 1234YF, can be found by clicking here. They have toxicity characteristics. a. R-1234yfb. Ammonia has the ability to use less than 0.5 lbs . Even replacement parts for equipment containing a flammable HC refrigerant must be compatible for that specific refrigerant. a. a. Brochure on New Climate-Friendly MVAC Refrigerants. b. Non-ozone depleting and have low global warming potentials. The distributor is selling section 608 certified refrigerant. a. Remove all remaining refrigerant, render the cylinder useless, and recycle the metal. b. HFO-1234ze also offers excellent energy efficiency, is cost-effective, and can be used in existing equipment design with minimal changes. On top of 134a and 404a I noticed that HoneyWells N40 brand is designed to be a replacement for 404a AND R-22. a. R-134a Now in Russian Federation and other countries large-scale oil terminals (volume of one tank exceeds 100 000 m 3, total volume of tanks exceeds 300 000 m 3) are designed and constructed.Therefore fire safety of such objects becomes a very important task, solution of which is hardly possible without detail fire risk assessment.This study is aimed to a solution of this problem. Which gas(es) would cause the LEAST damage to the environment? Why are HFO refrigerants less flammable than hydrocarbon refrigerants? Wear protective gloves b. filled to 95% of capacity A2L and B2L are low-flammability refrigerants with a maximum burning velocity equal to or smaller than 10 centimeter per second (cm/s) or 3.9 inches per second (in./s). The real question is how long will we be using HFOs until a new product comes out? HFO-1234ze is intended to replace R-410A in residential and light commercial air conditioning and heat pump applications while offering a 75 percent reduction in GWP. Recover the mixture into a separate recovery tank. HFO refrigerants contain at least one double bond (C=C), which is different from the traditional saturated halohydrocarbon refrigerants such as the chlorofluorocarbons (CFCs), hydrochlorofluorocarbon (HCFCs), and hydrofluorocarbons . Request a replacement from their certifying organization. Which of the following statements is true? Hydrofluoroolefins (HFOs) The last round of changes took place Manufacturers have addressed the safety issues around using A2L refrigerants in air conditioning However, it is likely that in some air conditioner somewhere, at some point in time, refrigerant will be They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable Why are some That is why that refrigerant is rated as a B2L from ASHRAE. To date, the use of HFO refrigerants and blowing agents has helped avoid the release of 170 million metric tons of CO2e into the atmosphere so far, equivalent to emissions from more than 35 million cars, almost all licensed cars in the UK. Freezer equipment can use propane (R-290) as long as the refrigerant charge does not exceed 5.3 ounces (150 grams); and new domestic refrigerators and freezers or combination refrigerator/freezer can use isobutane (R-600a) or R-441A as long as the refrigerant charge size does not exceed 2.0 ounces (57 grams). Two popular HFO refrigerants are HFO-1234yf and HFO-1234ze (See table 1 here). d. Higher natural background radioactivity, c. Increased rates of skin cancer in humans. HFO refrigerants, or Hydrofluro-Olefins, are a new class of refrigerants that have a much lessened global warming potential than its HFC alternatives. c. fossilization. trust that they always work out properly. Refrigerants emitted when cutting a line without properly evacuating the appliance.C. b. solvent conversion Which type of refrigerant typically has the lowest global warming potential? Why are some of the hydrofluoroolefins classified as A2L? A new refrigerant is introduced and then something is found to be harmful in that chemical and the refrigerant is replaced with a new and better line. How do refrigerant blends leak from a system? Hydrofluoroolefins (HFOs) have had a significant positive impact on the environment. The EU Regulation 517/2014 has recently been approved in a further attempt to curb the effects of Global Warming. In fact the GWP scale is based off of carbon dioxide, or R-744. Its only a matter of time before 410A is added to the list that 134a and 404a are on. Honeywell announced this week that they have begun production on four new HFO refrigerants under their Solstice brand name. Which refrigerant can be purchased by someone who is NOT a section 608 certified technician? By closing this message or continuing to use our site, you agree to the use of cookies. How many ozone molecules can each chlorine atom in the stratosphere destroy? The first HFO, jointly developed by DuPont and Honeywell, is HFO 1234yf which is sold under the brand names Opteon YF and SOLSTICE yf. b. Recovery equipment that relies on the compressor in the appliance and/or the pressure of the refrigerant in the appliance would be considered: Which of the following is NOT a "refrigerant" as it is used in section 608 of the clean air act? In addition to fines and being required to appear in court, what penalty can be imposed on service technicians who violate Clean Air Act provisions? I make a vertical slit of height d and width w at a depth H from the surface of the water. Proposed listing of HFO-1234yf as acceptable, subject to use conditions, for MVAC systems in newly manufactured nonroad vehicles 1. Some refrigerant blends that incorporate HC refrigerants in small percentages for oil return purposes include R-402A, -402B, -403A, -406A, and -438A. It's a strange heating spiral - in a warming world, we need more refrigeration to cool ourselves and our food, but the use of these cooling systems accelerates climate change, which in turn leads. What is being done in the U.S. to stop damage to the stratospheric ozone layer? Which type of refrigerant is the most harmful to stratospheric ozone? a. What characteristics of HFC refrigerants make them damaging to the environment? a. Notice the EPAs SNAP program only allows HC use in the U.S. in limited applications and in new equipment only. What is the strongest evidence that HCFCs are in the stratosphere? A key consideration for widespread acceptance of HFO refrigerants is the development of standards and codes for safe use of these mildly flammable A2L refrigerants. In other words, they are "artificial.". d. Ammonia. CFCs are classified as halocarbons, a class of compounds that contain atoms of carbon and halogen atoms. While hydrocarbons are not necessarily toxic like Ammonia it can still have detrimental effects if the concentration is high enough. What leak detection method is considered to be the most efficient for locating the general area of a small leak? These effects include increases in cataracts, skin cancer, and weakened immune systems. By visiting this website, certain cookies have already been set, which you may delete and block. A .gov website belongs to an official government organization in the United States. d. natural selection. In extreme cases asphyxiation can occur. What process applies to cleaning refrigerant for immediate reuse by oil separation and single or multiple passes through devices, like replaceable core filter driers, which reduce moisture and acidity? Acceptable, subject to use conditions, for new passenger cars and light-duty trucks only (March 29, 2011, 76 FR 17488; March 26, 2012, 77 FR 17344), Mildly flammable (ASHRAE A2L), but can be used safely, Models using HFO-1234yf include: Cadillac XTS, Chevrolet Spark EV, BMW i3 and i8, Chrysler 200, Chrysler 300, Dodge Challenger, Dodge Charger, Dodge Dart, Dodge Durango, Jeep Cherokee, Jeep Wrangler, Ram 1500, Fiat 500 and 500L, Alfa Romeo 4C, Honda Fit EV, Tesla Model S, Range Rover, and Range Rover Sport. c. Samples or air taken from the stratosphere over erupting volcanos show that volcanos contribute a small quantity of chlorine to the stratosphere compared to CFCs and HCFCs . As we try to decrease the GWP of synthetic blends further, typically by using hydrofluoroolefins (HFO), the result is often a refrigerant that is flammable with an A2L classification. Which refrigerant does not contain chlorine? Which of the following refrigerants contain chlorine? d. R-11, Which of these gases help form the earth's protective shield? Which of the following refrigerants has the lowest global warming potential? HFOs, and blends including HFOs, are expected to be used in air-conditioning and refrigeration applications. Why are HFO refrigerants less flammable than hydrocarbon refrigerants? HFOs do exist that have A1 (nonflammable) safety ratings; however, further research and testing needs to be done with these refrigerants. HFO refrigerants are in the category A2L, which means they are considered to be low toxicity and a rated as being slightly flammable. Which type of refrigerant is the most harmful to stratospheric ozone? An official website of the United States government. a. Hydrofluoroolefin (HFO) refrigerants are unsaturated organic compounds composed of carbon, hydrogen and fluorine. What color is the low pressure gauge on a typical gauge manifold set? Refrigerants in the A3 safety group are highly flammable. The first being that since these are new refrigerants the supply is very low and the demand will be increasing so obviously the price point is going to be high until the market balances out. d. They have ozone depleting potentials and have low global warming potentials. Solstice N40 Which of the following refrigerants is an HFO? Describe how the heartbeat affects blood flow. a. What must be done before disposing of any appliance containing a CFC, HCFC, of HFC refrigerant? ** d. Remain at least 5 feet away from the operating equipment. Visit our updated. a. Under SNAP, all flammable refrigerants, except HFC-152a and HFO-1234yf, are listed as unacceptable for use in new and retrofit MVAC systems. Retrofitting CFC-12 MVAC systems is also regulated under the SNAP program. It is the responsibility of the servicing technician to stay abreast of local, national, and global regulations that govern HC refrigerants. Resulting design criteria. How does the global warming potential of R-410A compare to that of carbon dioxide? R32 has a flammable range of around 15 points so it meets the definition of the GHS for a Category 2.1 gas. After the phase-out of a refrigerant, where will supplies of that refrigerant for equipment servicing come from? EPAsSignificant New Alternatives Policy (SNAP) program reviews substitutes within a comparative risk framework in a variety of industrial sectors that historically used ozone-depleting substances. b. Why are HFO refrigerants less flammable than hydrocarbon refrigerants? What are the characteristics of hydrofluoroolefins (HFOs)? d. Avoid violating the warranty on equipment. They are less flammable than hydrocarbon refrigerants, but most are still mildly flammable. They are "synthetic chemicals," not "natural.". a. c. R-22 Beginning in 2025, chillers will have to use a refrigerant with a GWP less than 750. When working with an appliance containing HCFCs or HFCs, which of the following does NOT require a person to be a Section 608 certified technician? begin the trip with 22300kg22300 \mathrm{~kg}22300kg of fuel. For connections with refrigerant containers for use in professional servicing, use fittings must be consistent with SAE J2844 (revised October 2011).