R-458A

[Jim Katen]

https://www.bluonenergy.com/residential/

Does anyone here have firsthand experience with this stuff? 

Is it a realistic drop-in replacement for R-22 or just hype? 

Everything that I can find online seems to be PR from the manufacturer. 

[Marc]

The truth on the R 22 drop-ins can be difficult to find but each of the ones I've been able to get detailed info reveals that they're all blends.

A blend is fine as long as the pressure/temperature points between the two components of the blend aren't too far apart but I've yet to find a single one with PT close enough to recommend it.  At 105 degrees, 458A has one at 178 psi and the other at 208.5 psi.  I'd be OK with the two points within 3 degrees of each other.

https://www.bluonenergy.com/wp-content/uploads/2018/09/bp-10-pressure-setpoints.pdf

If the points are too far apart, one flashes or condenses before the other, making them separate inside the refrigerant lines of the AC.

A lot of folks are offering various 'drop-ins' and likely making a lot of money but I stick with recommending a new 410A system. Daikin has a new refrigerant of their own design, not a drop-in but a 410A alternative, but I can't find a PT chart for it.

Edited June 27, 2020 by Marc

[Jim Katen]

I think it's actually a blend of 4 or 5 different refrigerants, with all different flash points. One of the papers that I read treated this as a selling point, saying that it made the blend up to 25% more efficient. This is why I never trust products where the only available information is PR. 

[plummen]

Theres been rumors around hvac supply houses for some time now about 410a equipt being phased out in near future.

I'd say it has more to do with patents running out than it is out performance of any particular product.

MO 99 seems to have been a popular go to around here for a while,especially since we cant get straight r22 from local supply houses anymore.