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Bluon Overview

This is a crash course in R-22 replacements, and using Bluon TdX 20. Here’s all you need to know to become a Bluon Tier 1 Accredited Contractor and start converting equipment to TdX 20!

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Why R-22 is going away


The availability of refrigerants is impacted by an international treaty called the Montreal Protocol. The treaty is designed to protect the ozone layer by phasing out substances known to deplete it.

Under the treaty, early CFC refrigerants (like R-11) have been successfully phased out of use in most of the world. Newer HCFC refrigerants (like R-22) are on a phase out schedule that reduces how much R-22 can be imported each year.

No more R-22 will be imported into the US by the end of 2020.

The Reality

The regulation is designed to slowly force HVAC-R users to replace their R-22 equipment with R-410A equipment. However, most users can’t afford to replace their equipment (which in many cases, still works just fine).

In fact, 65% of the world’s HVAC-R equipment is still R-22 equipment. In many cases, they still have 10+ years of useful life.


R-22 prices are rising dramatically. Soon R-22 will be difficult to obtain and cost prohibitive. As a result, R-22 replacements will become a major part of normal HVAC-R maintenance and repair jobs.

Replacements work differently than R-22

Replacement refrigerants are different than R-22 in important ways.

All Replacements Are Blends

R-22 is composed of a single compound, whereas replacements are blends of two or more compounds.

Blends Have Multiple Boiling Points

The different compounds in blends mean that they have multiple boiling points. This is why PT charts for blends have two columns instead of one, because their boiling and condensing temps are different.

All Blends Have a Glide

The different boiling points of the blend constituents results in a Glide. Contrary to industry opinion, glides can be beneficial in a properly designed refrigerant.

All Blends contain HFCs

Because blends are HFC-based they must carry the mineral oil required by R-22 systems. This can happen in one of the following ways:

  • Change MO oil to POE
  • Use a hydrocarbon in the blend
  • Innovate a way for the HFCs to mix with MO
Different Pressures and Temperatures

Replacements operate at different pressures and temperatures than R-22.

Correct SH and SC are Critical

Proper Superheat and Subcool are very important.

Replacements Perform Worse than R-22

Virtually all replacements perform worse than R-22 on energy efficiency and capacity (except Bluon!)

Challenges For Contractors

Replacement refrigerants present new challenges for mechanical contractors.

Some of the major challenges include:
  • Understanding the behavior of blends
  • Pre-existing problems can get worse
  • Accounting for pressure differences, controls, etc.
  • The impact of fractionation & volumetric issues
  • Tuning is mandatory
  • Client concerns: capacity and efficiency

Pre-existing Conditions

Pre-existing conditions or problems in equipment can get worse when you convert the system to a replacement. Be aware of these common issues:

Airflow Issues

Equipment might have airflow issues.

Metering Device Problems

TXVs may not work. Non-Adjustable TXV’s may require conversion.

Crank Case Heater Failures

It is more critical that crank case heaters are properly functioning.

Oil Levels

Oil levels might be high or low.

Pressure Controls

Low Pressure and High Pressure controls may need to be calibrated.

Refrigerant Charge

Equipment might be undercharged or overcharged. As a general rule of thumb:

↑ Overcharged = Lower efficiency
↓ Undercharged = Lower capacity

Replacements Operate At Different Pressures

TXVs Need Adjustment

Replacing the refrigerant means adjusting TXVs.

EEV Software

EEVs need the proper software profile.

Fixed Metering Devices

Fixed metering device will require more or less refrigerant.

Hot Gas Bypass

Hot gas bypass valves will need to be adjusted or replaced.

Pressure Switches

Pressure switches may need adjustment.

PT Charts

Remember that PT charts have two sides. This is because the constituents in the blend have different boiling and condensing temperatures. Blend PT charts are not absolute, but represent a range between fully liquid and fully vapor. Constituents may be in different states somewhere between that range. This is called “Fractionation” (see below).

Fractionation Impact

Multiple Temperatures

Blend vaporization/condensation happens at multiple temperatures as a result of fractionation.

Pipes Can Condense or Evaporate

Large or volumetric piping can produce unexpected condensing or evaporating issues.


Liquid leaks have smaller impact vs. vapor leaks. This is because in liquid form the constituents leak equally, but as vapor they leak unequally, which affects the blend’s ability to function.

Use the “20% Rule” with leaks: Generally if you’ve lost more than 20% on the vapor side, you should do a full recharge instead of just topping off.

Tuning Is Critical

Glides and Pressures

Glides can actually be beneficial when tuned properly.


Subcool requires liquid line pressure and temperature from bubble column from PT chart.


Superheat requires suction pressure and temperature from vapor column from PT chart. The measurement locations matter.

Target Temperatures

Although pressures are different, target temperatures for the evaporator and condenser should stay consistent.

Example: If an R-22 system is operating with a 40 F evaporator coil and 105 F condenser coil, then the replacement should run at those same temperatures, as measured at the coil outlet. The pressures will be different. Remember that the refrigerant glide will account for the temperature change occurring in the coil.

Dual Pt Charts For Blends

Remember that you are now using TWO columns on the PT chart, not just one.

1. Condensing Temps

Use the Liquid (Bubble) column to determine Condensing (Bubble) temperatures.

2. Evaporating Temps

Use the Vapor (Dew) column to determine Evaporating (Dew) temperatures.

Customer Concerns


The price of R-22 is skyrocketing as its availability declines. The price will only continue to rise.

Energy Cost

Most replacements drive up the electricity use of the equipment, which means higher energy bills for customers.

Loss of Cooling Capacity

Most replacements reduce cooling capacity, making the equipment less effective.

introducing tdx 20 (R-458A)

TdX 20 (R-458A) is an R-22 replacement designed to make your life easier, and your customers happy!

Energy Efficient

TdX 20 is the only blend that increases energy efficiency while keeping capacity similar to R-22.

Contractor Focused

TdX 20 comes with expert tech support and installation tools to make the job easier, such as the Bluon Mobile App.

Upgrades Equipment

TdX 20 reduces amp draw, lowers operating pressures, reduces compressor temps, and reduces vibration.

How It Works

TdX 20 is different than other replacements because it embraces the power of intelligently designed blends. Years of research and experimentation went into creating a combination of blends that work synergistically with one another to reduce inherent system losses.

Embracing Blends

TdX 20 is a blend of 5 constituents with staggered boiling points, designed to change phase in a carefully orchestrated sequence. Imagine 5 perfectly spaced dominoes knocking each other over. That’s how the TdX 20 blend works.

As a result:

  1. Heat is absorbed across more of the coil surface area, improving overall heat transfer.
  2. Compressor workload is reduced, resulting in less amp draw and lower compressor head temperature.
  3. Compressor stability is improved, resulting in less noise and vibration and more stable amp draw.

The reduced amp draw, better use of the coil, and reduced pressures and temperatures is what makes TdX 20 the only replacement that actually upgrades the equipment.

Bluon contractor focus

Bluon Has Your Back

We know that R-22 replacement can be a headache. That’s why we provide industry-first tools and support to make the job easier.

  • REAL tech support from industry vets
  • Growing knowledge base of best practices, and real world equipment testing.
  • Mobile app with access to conversion notes on thousands of R-22 systems.
  • Warranty protection

Real Tech Support

Call Us for Help

If you run into problems or have questions on the job, call our team of industry veterans anytime. We have decades of in-field experience, and we’ve pretty much seen it all.

Our techs can be reached through the tech support line in the app, or on the Bluon website.

Community Best Practices

Gain the experience and wisdom of the Bluon community and our growing knowledge base of replacement best practices, such as:


Use the right equipment, methods, and third party services to reduce recovery time.


Reduce evacuation time by using the right methods:

  • Minimize connections
  • Use only vacuum rated hoses (typically black) and equipment
  • Test equipment and connections before beginning evacuation
  • Follow OEM equipment guides (i.e. change oil, properly use vacuum pump ballast, etc.)

Only charge liquid (not vapor) with blends.
Recommended 80% charge at liquid line, followed by metering in the remaining charge at the suction line.


Know what to pay attention to, system specific information, tuning methods, and more.

If you encounter an adjustable TXV, 95% of the time you will need to close it by 1-4 turns.

Real World Testing & Sharing

Bluon technicians are actively installing TdX 20 in hundreds of systems. This helps us to:

Determine best practices, do’s and don’ts
Create system bulletins to guide our contractors
Outline solutions for challenging systems
Save you the frustration and learning curve

Our industry veterans are in the field each week to become your recon group on difficult jobs.

Using The Bluon Mobile App

The Bluon Mobile App gives you installation tools to simplify the R-22 replacement job.

Look Up Equipment, Get Answers Fast

Open the Installation Tools section of the app to search for thousands of HVAC equipment units by model number.

You can also sort for equipment based on manufacturer. Our expert techs are adding new units every day.

Get expert notes on the replacement process for that piece of equipment, as well as relevant unit details.

Wizard: Step By Step Replacement Guide

Helpful conversion guides and videos will walk you step by step through the TdX 20 installation process.

Use the TdX 20 PT chart to find Subcool and Superheat values to determine evaporating and condensing temperatures.

Enter pressures and temperatures into our calculator to help calibrate your TdX 20 charge.

Tdx 20 | R-458A conversion

Bluon Conversion Recap

  1. Check filters and replace as needed
  2. Check coils, clean as needed
    • Visually inspect for signs of leaks (oil spots, bubbles, etc.) – the best time to identify a leak is before you take the refrigerant out
  3. Verify proper airflow (generally 400 CFM / ton)
  4. Check general condition of unit looking for any abnormal wear and tear that might affect system performance (corroded contractors, clogged drain pains, etc.)
    • Replacing the refrigerant in a system with issues will make the existing problem worse
  5. Record refrigerant type and original charge (usually found on data plate)
    • TdX 20 is compatible with R-22 and R-22 replacement equipment
  6. Check metering device type
    • If fixed, make note of type and style (piston, capillary tubes, etc.)
    • If adjustable, verify thermostatic expansion device (TXV) responds to adjustments. In 95% percent of cases, you’ll need to close the TXV by 1-4 turns.
    • If TXV is non-adjustable, you may need to replace or convert to adjustable (conversion kits available)
  7. Baseline system performance under full load and record for future reference
    • Suction pressure/temperature, Liquid line pressure/temperature
    • Return Air (RA), Supply Air (SA), Outside Air (OA) if air cooled, Compressor amperage
    • Calculate Superheat and Subcool (use the Bluon Mobile App)
  8. Check for any pressure controls that may interfere with TdX 20 performance
  9. Recover refrigerant using standard trade practices (generally down to 10” Hg)
    • Record amount of refrigerant recovered as this will be used later
  10. Replace filter driers with HFC compatible driers within OEM recommendations
  11. Check seals, pressure test with nitrogen, check for leaks (bubbles, standing pressure test, etc.)
  12. Evacuate system to 500 microns using standard trade practices
    • Ensure system holds vacuum without rising above 1000 microns in 15 minutes
  13. Charge system through liquid line to 80% of nameplate or charge recovered (whichever is less)
    • Meter in liquid TdX 20 to the suction line until suction pressure is at least 30 psig
  14. Startup unit in accordance with OEM procedures
  15. Once stabilized, dial system in according to metering device type:
    • Fixed: charge to Superheat (8-12 F at the evaporator outlet / 8-20 F at compressor inlet*)
    • Adjustable: charge to Subcool (8-12 F at the liquid line*), adjust to superheat
      *Always refer to OEM recommendations first
  16. Label equipment with provided TdX 20 tags (attached to cylinder stem)

You’re Done With Step 1!

Now continue to step 2, the review questions. It takes about 15 minutes.