InspectApedia Diagnose & Fix What's Wrong at Your Building (2024)

R-401a refrigerant charge quantity for air conditioners & heat pumps:

This air conditioning repair article series discusses the the diagnosis and correction of abnormal air conditioner refrigerant line pressures as a means for evaluating the condition of the air conditioner compressor motor, which in turn, is a step in how we evaluate and correct lost or reduced air conditioner cooling capacity.

Typical R-410A Refrigerant Pressure / Temperatures

For every refrigerant type you use, you'll want to pick up a Refrigerant Pressure/Temperature chart from your supplier. A typical R-410A refrigerant pressure/temperature chart will give refrigerant pressures at various (ambient) temperatures ranging from below freezing to over 160 °F. Here are a few examples:

Notes to the table above

• Typical Low Side Pressure Range for R410A in the field: 115-120 psi
• Typical High Side Pressure Range for R410A in the field: 410-420 psi
• By 2025, high Global Warming Potential (GWP) refrigerants with a GWP of over 750, will be banned together with the systems using that gas.
• R410A has a GWP > 2,000.
• Measuring the refrigerant pressure in air conditioning, heat pump or other refrigerant systems can diagnose a range of operating problems including a refrigerant leak, over charging or under charging.

  Refrigerant pressure readings measured at the air conditioning compressor/condenser unit and which are found to be too low on the high pressure side (compressor output) or on the low pressure side (compressor input or suction line) can indicate a problem with the compressor's ability to develop normal operating pressure ranges and thus will affect the cooling capacity of the air conditioning system.

R410A Refrigerant Rules of Thumb

On a properly-charged and working air conditioning system using R-410A refrigerant

• R-410A Low-Side Typical Operating Pressure-Range = 102-145 psig (varying by indoor wet bulb temperature and outdoor ambient temperature, where higher heat loads increase the vapor line pressure)

Other Properties for R410A Refrigerant

• R410A temperature/pressure relationship: see the table above
• R410A alternative names: 50%CH₂F₂ / 50%CHF₂CF₃ - 410A is a mixture of difluoromethane (CH2F2, R-32) and pentafluoroethane (C2HF5, R-125)
• R410A boiling point: -55.3°F or -48.5°C at atmospheric pressure (sea level or 1 ATM)
• R410A critical temperature 72.8°C
• R410A density: 3.0 g/cm³, in gas form - as a colorless gas, Vapour density: 3.0, Vapor pressure at 21.1°C (MPa) = 1.383
• R410A molar mass: 86.47 g/mol
• R410A vapor pressure at 21.1°C (MPa) = 1.383
• R410A gas cylinder identification: rose color
• R410A status: in use

1. Outdoor ambient temperature

2. Typical low pressure or suction side pressure for R410A is about 120 psi, varying by ambient temperature, here assuming 75°F, may vary by equipment and metering controls

3. Typical high side pressure for R410A is < 600 psi at an ambient outdoor temperature of 95 °F, may vary by equipment

4. These psig readings for R-410A are what you'd expect the pressure of the gas to be in an enclosed container at the temperature given and at steady state.

These pressures are not suction or low-side nor compressor output or high-side pressures as those depend on the compressor model and the refrigerant metering device. This operating pressure for R-410A example was given by ACHR News in 2002:

... to produce an evaporating temperature of 40 degrees F and a condensing temperature of 115 degrees, the suction and head pressures would be 83 psia and 257 psia in an R-22 system, while they would be 133 and 406 psia, respectively, in an R-410A system. - Checket-Hanks, Barbara A., "Guidelines for Troubleshooting R-410A Systems", ACHR News 16 May 2002, retrieved 2016/08/29 original source: http://www.achrnews.com/articles/87788-guidelines-for-troubleshooting-r-410a-systems

An air conditioner or heat pump using R-410A refrigerant may operate at pressures exceeding 600 psi. A typical Carrier HVACR unit incorporates a high-pressure safety switch that operates at 610 psi and a low pressure (loss of refrigerant detection safety device) that operates at about 20 psi.

Low pressure refrigerant switches on Carrier HVACR typically open at 50 psi and close at 100 psi.

R-410A Refrigerant Pressure / Temperature Chart Downloads

Both older R-22 and R-134 operate at lower pressures than R-410A.

• R-410A PRESSURE TEMPERATURE CHART [PDF]
• Prah, Frank, "REFRIGERANT 410A INFORMATION", [PDF] Refrigeration Service Engineers Society, 1666 Rand Road, Des Plains IL 60016, (2001) retrieved 2017/09/20, original source: http://www.rses.org/assets/r410a/r-410a.pdf
• R410A PRESSURE-TEMPERATURE CHART [PDF] retrieved 2019/02/11 original source: https://www.bpa.gov/EE/Sectors/Residential/Documents/R-410A_Pressure_Temperature_Chart.pdf
• R410A SATURATION PRESSURE-TEMPERATURE DATA [PDF] Forane Refrigerants,

  data generated using the NIST REFPROP Database (Lemmon, E.W., Huber, M.L., McLinden, M.O. NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 9.0, National Institute of Standards and Technology, Standard Reference Data Program, Gaithersburg, (2010) retrieved 2019/02/11 original source: https://www.arkema.com/export/shared/.content/media/downloads/products-documentations/fluorochemicals/Forane-410A-Pressure-temperature-chart.pdf

• THERMODYNAMIC PROPERTIES of R410A [PDF], (2010) National Refrigerants Inc., Website: http://www.refrigerants.com, http://www.refrigerants.com retrieved 2019/02/11 original source: http://www.refrigerants.com/pdf/R410A_LINK.pdf
• REFRIGERANT PRESSURE / TEMPERATURE CHARTS for R-22, R-410A, R-134A, R-404A REFRIGERANTS [PDF] Advantage Engineering, Inc. 525 East Stop 18 Road Greenwood, IN 46142USA, Tel: 317-887-0729 Web site: www.AdvantageEngineering.com Email: sales@AdvantageEngineering.com
• REFRIGERANT TEMPERATURE / PRESSURE CHARTS for R-407, R-22, R410a, R-407c, R-134a, R404a, [PDF], Op. Cit.,
• REFRIGERANT PRESSURE / TEMPERATURE CHARTS for R-11, R-113, R-123, R-12, R-13, R-134A, R-114, R-14 or Freon-14, Tetrafluoromethane,R-22, R-23, R-410A, R-409A, R-416A, R-500, R-503, R-507, R-503 [PDF]

Watch out: Excerpts from Carrier’s Puron® Quick Reference Guide

“When charging 410A (liquid refrigerant only), use a commercial-type metering device in the manifold hose when charging into the suction line with the compressor operating.”

“Manifold sets should be a minimum 700 psig on the high side and minimum 180 psig low side, with 550-psig low-sided retard. Use hoses with a minimum 700-psig service pressure rating.”

“Be sure that servicing equipment and replacement components are designed to operate with [410A].” The recovery cylinder service pressure rating must be 400 psig, DOT 4BA400, or DOT 4BW400.

R410A Evaporating & Condensing Temperatures

Notes to the table above

1. To charge correctly, use the subcooling method
2. Typical pressure range at 75F: suction side 100-120 psi
3. HVAC Education Australia, The Essentials Of Working With R-410A [PDF] [no contact information given except website as cited below] retrieved 2019/02/11 original source: http://www.hvaceducationaustralia.com/Resources/PDF/The%20Essentials%20Of%20Working%20With%20410A.pdf
4. R410A HEAT PUMP HEATING CHECK CHART PAYNE PH16NA [PDF] for 16 SEER 2-Stage Split System Heat Pump using R410A, 2-5 Tons, (2012) Payne Heating & Cooling Systems, 7310 W. Morris St. D Indianapolis, IN 46231 USA, retrieved 2019/02/11
5. Suction side: add 25°F to outside air temperature and use the refrigerant chart to convert to psig
6. ACHR News, "Guidelines For Troubleshooting R-410A Systems" ACHR News, Main Office 2401 W. Big Beaver Rd., Suite 700 Troy, MI 48084 Phone: 248-362-3700 retrieved 2019/02/11 original source: https://www.achrnews.com/articles/87788-guidelines-for-troubleshooting-r-410a-systems<

Correcting R-410a Refrigerant Pressure & Leaks

Refrigerant Pressures & Pressure Diagnosis

• - home,
  • HIGH SIDE, LOW SIDE PRESSURE DEFINITIONS
  • TYPICAL REFRIGERANT PRESSURES found in air conditioners, heat pumps, refrigeration equipment for various refrigerant gases
  • COMPARISON of REFRIGERANT GAS PROPERTIES - table just below gives replacements for now-obsolete refrigerants like R22
  • COMPARISON of REFIGERANT GAS PRESSURES/TEMPERATURES - refrigerant pressure of various gases at the same temperature?
    

Refrigerant Pressure & Leak Correction

If you already know your refrigerant pressures are wrong or that you have a refrigerant leak, please see

• REFRIGERANT CHARGING PROCEDURE
• REFRIGERANT LEAK DETECTION
• REFRIGERANT LEAK REPAIR

If your air conditioning or heat pump system has lost its cooling capacity or won't start see

• REPAIR GUIDE for AIR CONDITIONERS.

...

Reader Q&A - also see

On 2020-04-09 - by (mod) -

On 2020-04-09 by carl

when installing 410a is the pressure gauge around 40
the same on a heat pump as it is on a regular air conditioner

On 2020-02-10 - by (mod) -

On 2020-02-10 by Dave Wane Plumbing

On a split system air conditioner, what should the approximate pressures be at condensing unit using 410A or 32A when the unit is off?
And what should the pressure be when the unit is operating?

Question:

2019/08/10 Karl Seyer

I have an AC compressor using R410, can I use an older gauge, or is the pressure too high for the the old Refrigerants, like R12 & R35?

Reply:

The pressure range will be within your older gauge set and in fact you may see an R-410a scale on the gauge face of some equipment.

...

Continue reading at - home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• - home
• DEFINITION of LATENT HEAT
• DEFINITION of SEER RATINGS
• DEFINITION of SENSIBLE HEAT
• DEFINITION of SUBCOOLING
• DEFINITION of SPECIFIC HEAT
• DEFINITION of SUPERHEAT
• - home
• - home
• SPLIT SYSTEM AC / HEAT PUMP REPAIRS

Suggested citation for this web page

R410A REFRIGERANT PRESSURE / TEMPERATURE CHARTS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES:

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.