pwned
03-11-2013, 04:14 PM
It is a generally accepted practice that to liquid charge blends with a large distillation range such as R-404A to avoid fractionation. The distillation point difference causes fractionation which the more volatile portion leaves first and leaving the left over richer in less volatile fractions.
Why is it ok to add 507 as vapor, but 410A is expected to be added as liquid only just like 404A?
R-410A is considered zeotropic and service standards in the US for A/C discourages vapor charging.
http://www.sciencedaily.com/releases/2013/08/130804081117.htm
Azeotrope blends are assigned 500 series numbers, such as HFC 507 and HCFC/CFC 502, CFC/HFC 500.
Azeotrope only holds true at the azeotrope temperature. DuPont says ~502 is around 0.3F glide.
http://www2.dupont.com/Refrigerants/en_US/assets/downloads/h45938_Suva_temp_glide.pdf
Tecumseh permits 507 charged as vapor:
http://www.tecumseh.com/en/canada/library/~/media/North%20America/Files/Guidelines%20and%20Manuals/Refrigerant%20Documentation_North%20America/Tecumseh%20Guidelines%20for%20Utilization%20of%20R404A%20and%20R507.ashx
507 does have ~0.3F of glide:
http://www.honeywell-refrigerants.com/americas/?document=hfc-retrofit-guidelines-hfc-404a-and-hfc-507-to-hfc-407f&download=1
410A <0.5F per DuPont, some others say <0.3F
http://www2.dupont.com/Refrigerants/en_US/assets/downloads/h45938_Suva_temp_glide.pdf
410A isn't perfectly azeotropic but neither are 500, 502 and 507.
Why is it ok to add 507 as vapor, but 410A is expected to be added as liquid only just like 404A?
R-410A is considered zeotropic and service standards in the US for A/C discourages vapor charging.
http://www.sciencedaily.com/releases/2013/08/130804081117.htm
Azeotrope blends are assigned 500 series numbers, such as HFC 507 and HCFC/CFC 502, CFC/HFC 500.
Azeotrope only holds true at the azeotrope temperature. DuPont says ~502 is around 0.3F glide.
http://www2.dupont.com/Refrigerants/en_US/assets/downloads/h45938_Suva_temp_glide.pdf
Tecumseh permits 507 charged as vapor:
http://www.tecumseh.com/en/canada/library/~/media/North%20America/Files/Guidelines%20and%20Manuals/Refrigerant%20Documentation_North%20America/Tecumseh%20Guidelines%20for%20Utilization%20of%20R404A%20and%20R507.ashx
507 does have ~0.3F of glide:
http://www.honeywell-refrigerants.com/americas/?document=hfc-retrofit-guidelines-hfc-404a-and-hfc-507-to-hfc-407f&download=1
410A <0.5F per DuPont, some others say <0.3F
http://www2.dupont.com/Refrigerants/en_US/assets/downloads/h45938_Suva_temp_glide.pdf
410A isn't perfectly azeotropic but neither are 500, 502 and 507.