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Engineers Newsletter volume 40 –2

HVAC : A Balanced Approach

1987, first targeting CFCs, then HCFCs. One of the constant themes History CFCs were replaced with HCFCs, throughout the history of the HVAC which have lower ozone-depletion industry is the search for a better refrigerant. When considering In the early years, the primary focus potential (ODP), or with alternative refrigerants, of the HVAC industry was simply on (HFCs), which have manufacturers need to balance finding a refrigerant that would zero ODP. The CFC phaseout was efficiency with environmental provide effective cooling. Many of completed in 1996. impact to determine the optimal the early refrigerants such as sulfur replacement. dioxide, methyl chloride and Due to their low ODP, the phase-out This EN will provide a brief history met that objective but dates for HCFCs were set out later— of refrigerants used in the HVAC posed safety hazards due to their from 2004 to 2030 (2040 in developing industry and the developing toxicity or high flammability countries). regulations. From there, we’ll discuss considerations for new and potential. existing equipment, along with . In the 1990s, refrigerant replacement options In the 1930s, concerns grew that the refrigerants and risks. (CFC) refrigerants were introduced being phased in because of their as safe alternatives to the chemicals favorable ODP were contributing to used before them. CFCs came to global warming. The global-warming dominate first and later potential (GWP) of refrigerants now HVAC because of their safety and became a factor. efficiency. Hydrochlorofluorocarbons (HCFCs) were added to the portfolio These concerns with global climate of refrigerant alternatives in the change led to the Kyoto Protocol, 1950s. created in 1997. Kyoto set reduction targets for greenhouse , including In the 1970s, environmental HFCs, in developed countries. Because concerns came into play. Scientists CFCs and HCFCs were already covered discovered that CFCs—and to a under the , they were lesser extent HCFCs—were not included in the Kyoto Protocol. contributing to the depletion of the . Where we are today. Both protocols allow each participating country to Montreal Protocol. Global concern control its own reductions of the about depletion of the ozone layer refrigerants to meet their compliance resulted in the Montreal Protocol, an obligations. In the United States, the international treaty that established U.S. Environmental Protection Agency phase-out dates for the use and (EPA) issued regulations under the production of ozone-depleting Clean Air Act to phase out the substances. It went into effect in

© 2011 Trane, a business of Ingersoll Rand. All rights reserved. 1

production and import of CFCs and Figure 1. Legislative actions involving refrigerant HCFCs. Montreal Protocol signed Kyoto Protocol went No new R-22 for service in US, Canada into effect No new equipment with R-123 in Figure 1 provides a summary of the developed countries major actions involving refrigerants in All CFC production stopped (R -11,R-12) in No new R-123 for service No HCFC production in developed and developing countries. developed countries developing countries No CFCs for in developed countries, no The dates on the chart are for the developing HCFCs in new equipment in developing countries United States and Canada (dates in countries other countries vary).

The Montreal and Kyoto protocols have 1990 2000 20102020 2030 2040 2050 set dates to ensure long-term availability. When production of a No R-134a use in new model continued use of recycled R-22,  refrigerant stops, the time lines allow automobiles in Europe R-123 for developing countries for the recycled, recovered and stockpiled supplies to continue to be Today continued use of recycled R-123 used without restriction. For example, No new equipment production of CFCs ended in 1996, but with R-22 in US, Canada continued use of recycled R-22 inventory of these refrigerants is still continued use of recycled CFCs readily available. Note: Included in the use of “recycled” refrigerants is also the use of stockpiled supplies of the refrigerant produced before the phase-out date. In addition, there is no restriction on the importation of recycled and recovered supplies of What’s ahead. Policy refrigerant. impacting nearly all commercially viable refrigerants available today has accelerated the development of While leakage rates can vary widely When considering both the direct and alternatives.The next family of among different HVAC products, good indirect environmental impact, HCFCs refrigerants, known as design and servicing can keep leakage and HFCs, because of their high energy (HFOs), have to a minimum. (See the sidebar on p. 4.) efficiency, can be the most properties similar to HCFCs and HFCs environmentally responsible and Years ago, when used CFCs and but with minimal direct environmental appropriate refrigerants available today service practices were less concerned impact. The first HFO on the market for many HVAC applications. has been developed to replace R-134a with minimizing emissions, rates for automotive applications and will were 2½ to 10 times what they are Evaluating alternatives. Let’s take a begin implementation this year in today. Due to advances in technology look at the refrigerants that are currently Europe. Implementation of HFOs will and the use of refrigerants with available, taking into consideration their lag in the HVAC industry as significantly lower GWP, the direct efficiency, direct and indirect manufacturers develop and test new environmental impact from HVAC environmental impact, and safety. alternatives, and global regulators equipment is now from 20 to 600 times lower than the older CFC designs. decide on a future path. Figure 2 compares the ODP, GWP and These reduced leak rates, coupled with energy efficiency of today’s commercial newer refrigerants, bring the direct refrigerants and potential future A Balanced Approach global warming impact to under 5 refrigerants. While there is no perfect percent of the application’s total global refrigerant, the chart shows that  When considering refrigerant warming impact. HCFC-123 (R-123), HFC-152a (R-152a) alternatives for the future, policy and HFC-32 (R-32) strike a good balance makers, the public, and manufacturers For hermetic systems, up to 95 percent between ODP, GWP and efficiency. must balance direct environmental of the total environmental impact is the However, the use of R-152a and R-32 is concerns (ODP, GWP, leak rates), indirect impact—the energy used to limited because of flammability. indirect environmental concerns power HVAC systems. According to the (energy efficiency), safety and U.S. Department of Energy, 83 percent Refrigerants such as CO2, hydrocarbons performance. of the primary power consumed in the and ammonia have zero ODP and a very U.S. is generated by the burning of fossil low GWP. Let’s take a closer look. Direct versus indirect impact. The fuels, which emits greenhouse gases. direct environmental impact of an HVAC system is dependent on the ODP and GWP of the refrigerant and the rate of refrigerant leakage into the environment.

2 Trane Engineers Newsletter volume 40–2 providing insights for today’s HVAC system designer

Carbon dioxide. CO2 has potential as present safety issues in application, a low-temperature refrigerant in service and recovery because they are Green building and refrigerant refrigeration applications. However, it highly flammable. selection has very low efficiency in HVAC applications, more than 20 percent Ammonia. Ammonia has been used Green building rating systems such as below the efficiency of R-22 and  for years and has potential for low- USGBC’s LEED (Leadership in Energy and Environmental Design) and GBI’s R-410A, due to operation above the temperature and process chiller critical point of CO in these Green Globes take refrigerant usage into 2 applications in remote locations or consideration. The current LEED rating applications. Today’s equipment would where people density is low. Its system uses a formula to calculate the therefore consume at least 20 percent flammability and high toxicity strictly impact of , global more energy with CO2 to get the same limit its broader use. warming, equipment life, leakage rate, cooling tonnage, compared to the and refrigerant charge. The Green Globes rating system accounts for ozone existing HCFCs and HFCs used today. Maintaining a balance between the depletion, global warming and leak lowest possible refrigerant emissions detection. Switching from to CO2 and the best possible energy efficiency to reduce direct environmental impact is the key to being both By following the criteria in the rating systems, the selected refrigerants can (5 percent), while significantly environmentally and economically increasing the indirect impact (95 help the project achieve points toward responsible. Achieving this balance in a green building status. For example, most percent), would not be a good trade- cost effective manner is critical in order centrifugal chillers (both R-123 and  off. to make these new designs affordable R-134a) can achieve the refrigerant for the end user. points for LEED Energy and Atmosphere credit 4. Many split systems, due to the Hydrocarbons. Hydrocarbons may large volume of refrigerant, cannot. perform well in stationary applications, but they For more information, see www.usgbc.org or www.thegbi.org.

Figure 2. Overview of the environmental impact of current refrigerants

Energy efficiency ODP GWP COP (at typical chiller conditions) (R-11=1.0) (CO2=1.0) (000s) 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 1.0 0.8 0.6 0.4 0.2 0 24681012

CFC-11 CFC-12 HCFC-22 HCFC-123 HFC-134a HFC-410A HFC-32 some flammability HFC-152a some flammability HFC-245fa HFO-1234yf some flammability

R-290 () flammability

R-600a () flammability

R-744 (CO2 ) R-717 (ammonia) flammability & toxicity lower efficiency higher

3 Trane Engineers Newsletter volume 40–2 providing insights for today’s HVAC system designer

A note regarding equipment using Options for Existing HFCs: There are no specific record- Use best practices to minimize Equipment keeping requirements or maximum environmental impact leakage rates for this equipment, but Best practices in design and servicing can So, what do we do with existing due to direct global warming, venting of keep refrigerant to minimal levels. In equipment containing refrigerants that these chemicals is also prohibited. In fact, a Trane study conducted as far back as will be phased out? the future, maximum leakage rates will 1997 determined the annualized total loss most likely cover the HFCs as well. rate for every single R-123 chiller that Trane There is no definitive answer. However, had under service contract at the time. The study included all leaks whether from there are options and a logical Track the equipment performance.  accidental discharge, servicing or normal progression to determine the best The performance data of the equipment operation. It showed that of 2768 R-123 solution for each project. can be provided either by the building chillers studied, only 16,229 pounds per year of charge was lost—less than 0.4575 automation system (preferred), or by Options: percent annual leakage rate. the original nameplate data of the • Maintain existing refrigerant equipment. Proper service practice It's important to note that operating should be able to maintain close to pressure can also impact how likely a leak • Replace the refrigerant is to occur and how much refrigerant will original performance on most escape during a leak. In addition, • Replace the equipment equipment, but individual equipment innovative technologies can be employed monitoring will provide an even better that minimize the refrigerant charge for a Evaluate existing equipment performance baseline. given amount of refrigeration or cooling capacity, with the percent charge reduction directly reducing refrigerant emissions over The first step is to evaluate the current Evaluate refrigerant changeout the life of the equipment by the same inventory of equipment. When tracking amount. So, use of low pressure technology the current inventory, obtain records Before replacing a refrigerant, with reduced refrigerant charge levels can that document the energy performance determine the capacity and efficiency result in nearly an order of magnitude and refrigerant leakage rate of existing reduction in lifetime emissions compared to impact. This impact is clearly other higher pressure centrifugal chillers. equipment. understood in some equipment types, such as centrifugal chillers, where Track leakage rate of equipment. The replacements are clearly defined and decision gets more complex with the U.S. Clean Air Act requires that leakage several years of performance data has replacement of R-22. Many solutions rate data records be kept for all been accrued. are available, and it is impractical for equipment with more than 50 lbs of equipment manufacturers to test and For other equipment, there are many refrigerant charge. These records analyze all of them. Generally, these replacement options in the marketplace, should be available either from the replacements incorporate the use of and even more claims of seemingly owner's maintenance records or from multi-chemical blends in order to mirror miraculous capacity and efficiency the records of the servicing contractor. the properties of R-22. Note: Because improvements by using these If records are unavailable, then record of its higher operating pressure,  replacements. Basic physical properties, keeping should begin immediately to R-410A cannot be used in R-22 as well as industry experience, have understand the state of the existing products. equipment. clearly shown that any refrigerant replacement in existing equipment will Blends work in many applications, but As of January 2011, for equipment with result in some sort of capacity and be sure to weigh the following risks: more than 50 lbs of refrigerant charge, efficiency reduction. The specific the U.S. EPA’s maximum allowable reduction depends on the type of • Different leakage rates leakage rates over a 12-month period equipment and the specific Concerns exist in the marketplace are: replacement refrigerant. Note: When about what happens when retrofitting existing equipment, do not • Commercial refrigeration:  refrigerant leaks occur. The use a flammable refrigerant in 35 percent different components in the blend equipment that was not specifically could potentially leak at different • Industrial process refrigeration:  designed for it. rates, and therefore change the 35 percent composition and performance of Replacements for the refrigerants R-11 the equipment. When these • Comfort cooling: and R-12 are relatively straightforward 15 percent replacement refrigerants (R-123 and R-134a, respectively). The incorporate as many as four or Venting is prohibited for any equipment, more chemicals in the blend, these regardless of size. concerns increase.

4 Trane Engineers Newsletter volume 40–2 providing insights for today’s HVAC system designer

• Change in oil Review and assess Today we have good, solid refrigerant options and availability with HCFCs and In many cases, a refrigerant After you have reviewed the data and HFCs. There’s no need to panic. The changeout requires a change in the evaluated the possibility of refrigerant future will bring different options, oil needed in the system. CFCs and changeout, determine the best solution challenges, and opportunities. HCFCs are able to use mineral oil for your particular application. with the refrigerant. HFCs, By Jeff Moe, director, global policy and advocacy however, generally require the use In most cases, retaining the existing for the Center for Energy Efficiency and of POE or other synthetic oils. refrigerant in the equipment, or Sustainability, Ingersoll Rand; Mike Thompson, replacing the equipment altogether will global leader of refrigerant strategy, Trane; and So that an oil change may not be Beth Bakkum, information designer, Trane. You required, many of the R-22 make the most sense. If leakage rates can find this and previous issues of the Engineers substitutes incorporate a small with the existing refrigerant cannot be Newsletter at www.trane.com/EN. To comment, amount of hydrocarbons, such as contained to a minimal level with the e-mail us at [email protected]. , in order to improve their current refrigerant, then it is unlikely miscibility with mineral oil. that leaks will be contained with the new refrigerant. In addition, significant However, the refrigerant and oil investments in inefficient equipment chosen must have sufficient that will result in a loss in capacity and solubility and miscibility throughout efficiency will often not be the most the refrigeration system—which attractive solution. In many cases, may not be the case for some R-22 investment in minimizing leaks and substitutes and mineral oil. If in maintaining the equipment to its peak doubt, consult the unit or energy performance will result in a manufacturer for the smaller up-front investment and better required oil type. life cycle cost. When a refrigerant and/or oil changeout is evaluated, all the components of the refrigeration system must be scrutinized for Summary compatibility with the refrigerant and oil. Gaskets and o-rings are of Since the early 1900s, the HVAC particular importance because they industry has been faced with the may shrink or expand and cause a challenge of constantly changing refrigerant release. It is strongly refrigerants. While change is constant, suggested that the gaskets and  it’s important to remember that the o-rings be proactively replaced industry has successfully navigated during a refrigerant or oil refrigerant phaseouts in the past and conversion. can apply the lessons learned to future • Future availability and GWP transitions. As an industry, the key is to carefully consider alternatives and If a proprietary blend is used for an strike a balance that is financially and alternative refrigerant, it should be environmentally responsible. ensured that the blend will still be available in the future. In addition, many of these blends are very high in GWP. The GWP of refrigerants will likely be regulated or taxed in the coming years, making many of the alternatives unattractive.

5 Trane Engineers Newsletter volume 40–2 providing insights for today’s HVAC system designer

New On-Demand Courses Now Available Engineers

Upgrading Existing Chilled-Water Newsletter Systems. (This program provides LIVE! designers with specific strategies for To register, contact your chiller upgrades, optimization or local Trane office. replacement; reusing components of a system and help you Upgrading Existing identify areas where control upgrades would be beneficial. Chilled-Water Systems ASHRAE 62.1 and 90.1 and VAV Now available on-demand Systems. (GBCI LEED-specific) at www.trane.com/ContinuingEducation This program discusses the potentially conflicting requirements and design choices. June 2011 High-Performance

ASHRAE 62.1: Ventilation Rate VAV Systems Procedure. This program covers the Ventilation Rate Procedure for calculating zone and system ventilation October 2011 airflow, which still exists in the standard Dedicated today. As a prerequisite to obtain LEED certification, this program will help Outdoor Air Units viewers understand the requirements of the Standard.  Visit www.trane.com/ ContinuingEducation to view or to see a complete list of courses.

Trane, Trane believes the facts and suggestions presented here to be accurate. However, final design and A business of Ingersoll Rand application decisions are your responsibility. Trane disclaims any responsibility for actions taken on the material presented. For more information, contact your local Trane office or e-mail us at [email protected]

6 Trane Engineers Newsletter volume 40–2 ADM-APN041-EN (June 2011)