Presentation on theme: "Responsible Use of Refrigerants in HVAC"— Presentation transcript:
1 Responsible Use of Refrigerants in HVAC PLEASE MUTE CELL PHONESResponsible Use of Refrigerants in HVACJulian de BulletASHRAE Distinguished LecturerDirector of Industry RelationsMcQuay International
2 It’s About the World…..Globally the Issues are the Same……….
3 History of Refrigerants 1830s - Jacob Perkins - Vapor Compression (ether)John Gorie - Patent for Vapor Compression Cycle1859 R-717 / R-718 (Ammonia / Water)1866 CO2 - Naval ApplicationsR-717 (Ammonia) Commercial Refrigeration - Karl LindeR-764 (Sulfur dioxide)1920s -R-600a (Isobutane) & R-290 (Propane)Willis Carrier - R-1130 (Dielene)R-30 (Methylene Chloride)Considering the nearly infinite possible combinations of atoms it is amazing only a handful are good refrigerants.Thomas Midgley found the Fluorocarbons in the 1920sSince then, many other substances have been evaluated but they did not meet the requirements previously discussed.Next we will have an overview of fluorocarbon chemistry
4 Fluorocarbons CFCs, HCFCs and HFCs Limited Combinations Adding Chlorine Or Bromine Increases ODPAdding Fluorine Increases GWPAdding Hydrogen Increases Flammability And Lowers Atmospheric LifetimeCFCs HCFCs and HFCs are fluorocarbonsThere are only so many ways you can arrange the atoms to come up with new refrigerantsThe figure shown here shows what happen as we change the composition of the moleculesAdding Chorine or bromine moves us to the lower rightThis increases the ODPAlso tends to increase toxicityCFCs and HCFCs are hereAdding Fluorine moves us to the lower leftincreases GWPHFCs are hereAdding Hydrogen moves us up the figureincreases flammabilitytends to shorten atmospheric lifetime which is goodhydrocarbons are herePretty much all the substances possible that remotely meet the criteria we discussed earlier are known
5 Ozone Depletion was Detected in the 70’s……….. By the mid1970’s concerns began to surface about the thinning of the ozone layer and whether CFC’s may be in part responsible. The work done by Rowland and Molina led to the ratification of the Montreal protocol in It required the phase out of CFC’s and HCFC’s.
6 Refrigerants Circa 1987Common HVAC Refrigerants Include CFC-11, CFC-12 (ODP=1.0), HCFC-22 (ODP=0.05)Chiller Efficiency kW/tonLow Pressure Chillers Lose 25% Of Charge Annually
7 Montreal Protocol Corrective Measures HFC-134a (ODP=0) Replaces CFC-12 for Chillers and HCFC-22 for most Commercial HVAC SystemsHCFC-123 (ODP=0.02) Replaces CFC-11These Chillers Tightened Up (High Efficiency Purge, Portable Refrigerant Vessels, Blankets etc.)New refrigerant solutions were developed with HFC’s taking on a major role. HCFC’s continue to be phased out. HFC’s have no ODP and are not subject to any phase out. Owners of CFC-11 chillers had options to tighten up their existing chillers to avoid loss of CFC’s and maintain operating efficiencies.
8 20 years later….Ozone Depletion Continues….. 2005 ‘Hole” wasone of largest anddeepest ever….Stratospheric ozone depletion continues. Assuming the continued phase out schedules, Antarctic ozone is projected to return to pre-1980 levels by 2060 to 2075.Latest NASA predictionsdelays recovery until2068…..nearly 20 yearslater than previouslybelieved…..
10 Montreal Protocol –Changes Made on Friday September 21st, 2007 Phase Out Schedule – Developed Countries100%Consumption cap reducedfrom 35% to 25% in 201080%65%60%Consumption40%25%2015 Service Tail Review20%10%0.5%0%199620042010201520202030Phase Out Schedule – Developing Countries100%Freeze90%Current:Consumption cap steadilyreduced starting in 2015There were no changes to the end dates. Trane did not get there extension or exemption. There were significant reductions to consumption especially for developing countries. It is too early yet to determine what additional HCFCs will be in involved in the additional 10% reduction starting in 2010.80%65%60%Previous:Consumption capped at2015 levels until 2040Consumption40%32.5%20%2.5%0%201320152020202520302040Note: acceleration shown in light blue
11 AVAILABILITY OF REFRIGERANT (Dupont & ICI Projections) Tons (000)30025020015010050HFC134aHFC410AHCFC22HCFC123Year4197
12 And Don’t Forget HCFC-22HCFC-22 phase-out in 2010 for new equipment and 2020 for service tail productionConsider alternatives for HCFCs nowRecommended actionsSelect high efficiency units that use zero ozone depleting refrigerants like HFC-410A, HFC-134a and HFC-407CWith only two years remaining before R-22 is phased-out in new equipment, you need to begin to make refrigerant choices today. The most common are HFC-410A, -134a and -407C…all zero ODP refrigerants.
13 HCFC-22 Issues- Clarification Allow the sale of window air conditioners, packaged terminal air conditioners, and some commercial refrigeration units after Jan. 1, 2010, if they were manufactured before Jan. 1, Stockpiling of this equipment is allowed under the rule. • Allow the sale of pre-charged appliance components and parts manufactured (in the traditional sense), such as condensing units, line sets, and expansion valves, used for servicing as long as they were manufactured before Jan. 1, Stockpiling of this equipment is allowed under the rule. • Ban the sale and installation on or after Jan. 1, 2010, of pre-charged R-22 air conditioners (such as split systems) and refrigeration appliances that require field charging. Contractors are advised not to stockpile this equipment. • Permit servicing and repair work that requires the refrigeration loop to be opened and closed. There was a question as to whether this activity would be banned because it could be interpreted as ‘manufacturing’ after the Jan. 1, 2010 deadline.”
14 ASHRAE Standard 34ASHRAE Standard 34, Designation and Safety Classification of Refrigerants lists over 100 refrigerants, although only very few are used on a regular commercial HVAC basis.
15 ASHRAE 34 SAFETY GROUPS B3 A3 A2 B2 A1 B1 High Flammability PropaneButaneHigh FlammabilityLow FlammabilityNo Flame PropagationA2R-142b, 152aB2AmmoniaA1R-11, 12, 22, 114, 500, 134aB1R-123, SOToxicity and flammability are the two key parameters used by ASHRAE to indicate the safety level of a refrigerant. The standard has adopted a matrix indicating the relative levels of these two parameters.2Lower ToxicityHigher Toxicity9436
19 ASHRAE Standard 15 What is ASHRAE 15? An industry standard that specifies safe design, construction, installation, and operation of refrigerating systemsEstablishes safeguards for life, limb, health, and property, and prescribes safety standards
20 Mechanical Room Safety Check: Location of inletvents in relationto exhaust outlets ?Location of roof drains ?Rupture discoutlet locations ?Is there a tightseal on doors ?Purge ventsto outside ?Are safety rupturelines the right size ?Is access to mechanicalroom restricted ?Review this data carefully to recognize areas where the standard addresses these long standing equipment room problems.Are drain valves connectedto evacuation devices ?Are there anypit areas in theroom ?Where do thefloor drainsempty to ?
21 Mechanical Room Per ASHRAE 15 Relief discharge shall be located not lessthan 20 ‘ from ventilation opening andnot less than 15’ above ground level (9.7.8)All indoor machineryrooms must be ventedto the outdoors utilizingmechanical ventilation& 4Purge systems and relief devicesmust be vented to outside (8.16)Access to mechanicalroom shall be restricted.Tight fitting doors openingoutward (self closing if theopen into the building)adequate in number toensure freedom of escape.No other openings that wouldpermit passage of escapingrefrigerant (8.13)Here are the sections where the standard specifically addresses main equipment room issues.Refrigerant sensors are located in areas whererefrigerant vapor from a leak will be concentratedso as to provide warning at concentration notexceeding the refrigerant TLV-TWAThe total amount ofrefrigerant stored in amachinery room in allcontainers not providedwith relief valves & pipedin accordance with standardshall not exceed 330 lb.. (11.5)
22 Energy Efficiency What About GWP and Leakage Rates? For chillers, (Indirect) global warming gas emissions (CO2) at the power plant account for more than 96%of the Total Equivalent Warming ImpactEnergy EfficiencyIn a study by ORNL they determined that over the lifetime of operation more than 96% of the global warming gas emissions are from the electricity to operate the chillert. Clearly the focus of our industry will be on improving energy efficiency.Oak Ridge National Laboratory (AFEAS/DOE)Energy and Global Warming Impacts of HFC Refrigerants and Emerging Technologies Nov 1997
23 Number of Leaks Detected per Unit The industry continues to employ better manufacturing techniques to minimize leakage rates.Reference: Zero Leaks by Denis Clodic from the ASHRAE Bookstore
24 Climate Change & HFC Refrigerants 1 kg R-12 = 10,600 kg CO21 kg R-134a = 1,430 kg CO21 kg R-410A = 2,088 kg CO21 kg R-404A = 3,922 kg CO2GWP=How much a given mass of GHG contributes to global warmingHFC emissions covered under the Kyoto Protocol – Represent less than 2% of all GHG emissions
25 Climate Initiatives Waxman/Markey House Bill- Energy Efficiency The goal would be for the model building energy codes to be updated every three years to reduce building energy consumption by 30% such target to be increased to 50% incremental reductions in building energy consumption for new code editions released after January 1, 2016, with the ultimate goal being “net-zero-energy” buildings.The starting baselines would be the 2004 IECC and ASHRAE Standard
26 Waxman/ Markey Bill- Climate Climate InitiativesWaxman/ Markey Bill- ClimateThe Draft provides for an HFC regulatory program under the Title VI of the Clean Air Act, and as expected, provides for (1) a cap and reduction schedule, (2) allocations to HFC Producers, Users and Importers (both bulk and products-containing); and several other provisionsThe Draft proves for an initial cap in 2012 that is based on the average of production (and 100% of HFC and HCFC production). The number is then to be reduced by 6% in the first year, and then 3% each year until 2028. EPA is given authority to set this baseline within the bounds of 380 and 280 MMTCO2e
27 Total Equivalent Warming Impact (TEWI) TEWI - Tool to estimate global warming impact of various technologiesTEWI estimates CO2 emissions of a given system over its lifetimeDirect: equivalent CO2 emissions caused by direct leakage or loss of refrigerantIndirect: CO2 emissions due to energy consumption by the system
28 TEWI – Major FindingsNew products have half the carbon footprint than products manufactured 35 years agoEnergy efficiency is key to reducing greenhouse gas emissions from HVACR equipment
29 Ohnishi Basis for ICCP/TEAP report TEWI is the sum of the effect of a direct discharge of refrigerant plus the effect of carbon dioxide emissions due to energy use over the lifetime of the equipment. TEWI’s are based on carbon dioxide which has a GWP of 1.0 The refrigerant portion is converted to the amount of carbon dioxide that would have an equivalent affect and then added to the power station emissions also in carbon dioxide. Other comparisons take into account a cradle to grave approach. Always the direct emissions of the refrigerants have a minimal impact.Ohnishi Basis for ICCP/TEAP report
30 ARI Standard 550/590Chiller Certification and IPLV
31 The Industry ARI Standard Part Load Analysis (IPLV) % Load % HrsSystems Solution- Notice the huge change in how the entire industry has changed the load profile to which every chiller is compared.- The biggest change is the 50% load point which went up over 33% !!! … perfect for the dual design.42
33 Full Load Vs. Annual Load 7 story office buildingMinneapolis375,000 ft2Floor by floor VAVSingle chiller plant as shown earlierDesign performance shows the chillers as dominantAnnual performance shows fans are dominant and pumps are significant
34 ASHRAE Standard 147Reducing the Release of Halogenated Refrigerants from HVAC & R SystemsReplaces Guideline 3Includes HFC RefrigerantsNew InitiativesARI- Responsible Use Guideline for Minimizing Fluorocarbon Emissions in Manufacturing FacilitiesASHRAE Standard 147 prescribes practices and procedures to reduce release into the atmosphere of halogentaed refrigerants used in refrigerating and air-conditioning systems.ARI has published this Guideline to encourage refrigerant containment and environmental protection in Manufacturing Facilities.
35 Other Refrigerants R-718 Water R-717 Ammonia R-744 CO2 R-290,600,600a (Propane, Butane, Isobutane)R-407cR-410aSome alternative refrigerants.
36 Natural Refrigerants - Water R-718 Refrigerant In Absorption ChillersSafe, Abundant, Environmentally FriendlyCOP = 1 (Centrifugal COP = 6.4)Current Energy Rates Offer Poor Life Cycle Analysis In AmericaCommon In JapanWhen you pick absorption chillers you get water as a refrigerantIt is safe, abundant, environmentally friendlyIt has a relatively low COP=1Compare that to a centrifugal with a COP = 6.4It does run off a direct energy source (natural gas) as opposed to electricity.With electricity, you should consider how the power is generatedCurrent energy rates make it difficult to show good life cycle analysisAn absorption chiller is twice as expensive as centrifugalThey are the norm in Japan and centrifugals are rarePREDICTIONNiche applications in hybrid plants and cogenIf energy rates change significantly (a possibility with deregulation) then more absorption may be used
37 Natural Refrigerants - Ammonia R-717 Higher Toxicity And Lower Flammability (B2)Environmentally FriendlyEfficientSpecial Safety Efforts Required (Std 15)Guarded PlantsAmmonia is a “natural refrigerant”It has high toxicity and is slightly flammableIt is environmentally friendlyIt is very efficientIt requires special safety efforts outlined in Std 15and typically requires a supervised plantPREDICTIONContinued presence in industrial applications and some large institutional projects.European Built Ammonia A/C Chiller
39 Refrigerants CO2 R-245fa Hydrocarbons Water Carbon Dioxide is also a natural refrigerant that was used up to the turn of this centuryIt is safeODP = 0GWP =1It is very in efficientThe critical point is very lowIt is also very high pressure - over 1450 psiASHRAE has ongoing research in the trans-critical region for CO2PREDICTIONCascade refrigeration (resolves low critical point issue)Possible automotive air conditioning application
40 Flammable Refrigerants Propane And ButaneMajor Safety Concerns+35% Domestic Market In N. Europe8% Domestic World MarketNot Popular In North AmericaIn the U.S, OSHA Regulations would prevent these refrigerant from being used in confined spaces.
41 Synchronous brushless DC motor CompressionBest Performance And Lowest Cost Always Starts With CompressionRefrigerant Choice Drives Compressor DesignExamplesMagnetic BearingHigh Speed Synchronous DC MotorsDC Rotary And Scroll Compressors (Japanese Technology)Inverter TechnologySynchronous brushless DC motorMagnetic Brgs
42 AHRI CFC Chiller Task Force Most recent estimate: 27,000 CFC chillers still in N.A.Summit of AHRI and Efficiency Advocates- ACEEE, ASE, Utilities etcPlan to use Stimulus moneys to replace CFC chillersThree targetsFederal BuildingsState and Local Government BuildingsCommercial BuildingsPlan:Gain consensusDevelop communication piecee.g. CFC chillers at 0.9 kw/ton vs 0.56 kw/ton or standardsWrite legislative language to finance using Stimulus funds
43 Considerations when Replacing or Retrofitting Difficulties in Servicing and Maintaining Existing HCFC Equipment.Declining Availability of HCFC Refrigerants.Adequate Life-Cycle Timeframes for New Equipment using HCFC’s.Determining the Remaining Life-Cycle of Existing Equipment.Understanding Alternative Equipment, Refrigerant Options and Compatibility of Both Refrigerants and Equipment.Containment is Key……………
44 Steps we can take today To have sustainable HVAC solutions Need to focus on overall global impactNo one solution works for everyoneA focus on components aloneLimited by efficiency of individual componentsNeed to look at the performance of the systemA focus on refrigerants aloneMay increase energy consumed (indirect effect)HFC’s are a good solution todayFocus on overall impact of buildingReduce leaks in systemIncrease energy efficiency through performance standards
45 Innovative Technology Award Innovative Design Award