What is the R-404A pressure at 40F and 100F?
On the R-404A PT chart, 40F saturation is about 84 psig and 100F is about 234 psig. Read the low-side (suction) pressure and its saturation temperature for superheat, and the high-side (liquid) pressure and its saturation temperature for subcooling. R-404A is used mostly in low-temperature and commercial refrigeration (reach-in freezers, walk-ins, ice machines), where the evaporator normally runs well below the comfort-cooling range.
Does the R-404A PT chart have glide (bubble and dew)?
R-404A is a near-azeotropic HFC blend with a very small temperature glide, so field pressure-temperature charts, including this one, list a single saturation column rather than separate bubble and dew points. That is standard practice for R-404A. The larger-glide zeotropic blends that need two columns are R-407C, R-448A, and R-449A.
Is R-404A being phased out?
R-404A has a high global warming potential, so under the AIM Act its production and import are being stepped down and new equipment is moving to lower-GWP alternatives such as R-448A, R-449A, R-454C, and CO2. The large installed base of R-404A reach-in coolers, walk-ins, ice machines, and transport units still needs service, so the PT chart stays in daily use.
What units is this R-404A PT chart in, and how do I convert to kPa or Celsius?
The table is in psig (gauge pressure) and degrees Fahrenheit, the field-standard units in North America. To convert pressure to kPa (gauge), multiply psig by 6.895. To convert temperature to Celsius, use C = (F - 32) / 1.8. For example, 100F is about 37.8C.