410a General Question

[J-Fish]

I maintain several buildings for the county and they have always keep everything strictly R22. In the past I have had no dealings with 410 a but I have a couple of jobs coming up soon that I will have to maintain in the future.

Someone at the parts house told me that I can not accurately add additional 410 a to an existing unit with out recovering and then weighing in the exact charge.

Someone else told me that you could add what you need to get the job done.

A third person told me that if it did not come from the same jug of gas it would not mix well and give me increased head pressure just like having non condensible in the line.

Can anyone that deals with the typical 410a system send me down the wright path until I have a chance to read up on the subject.

[snewman24]

R-410A is a near azeotropic and doesn't tend to fractionate, so you can top off a system. Watch the following educational presentation for a good overall look at servicing with R-410A: http://www.lennoxcommercial.com/res/pres/elearning-r410a/frame1.htm

and this is also somewhat helpful:
http://www.epatest.com/R410A/manual/manual.jsp

[big johnson]

If you loose less than half the charge, "topping off" will work. The way I deal with it is by system size. If you've got a 120 ton chiller, and lost 1/3 of the gas, I would top off after repairs are made. A small roof top heat pump, say 2-5 tons, suck it all out, wiegh it back in.

[brian in mass]

R-410a is a tireny blend (three to make one), when introduced to atmospheric it will fractionate at three different rates. This causes it to no longer "be" 410a. When you find a leak....what you have has lost some of it's make-up. Therefore whoever told you to recover and weigh in new product was correct. And a word to the wise, carefull storing it at high temps.

[yorkdude]

take the test free

http://www.epatest.com/faq/R410A/