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Old 02-27-2011, 06:35 PM   #16
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TXV and superheat


yes there is, EPA certification in US maybe not in canada................

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Old 02-27-2011, 06:48 PM   #17
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yes there is, EPA certification in US maybe not in canada................
Oh, you mean you need an EPA Certification(section 608). Since there is no EPA License. Which doesn't apply to HFCs. So if he is working on R410A, there is no EPA certification.
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Old 02-27-2011, 07:22 PM   #18
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i'm going to leave this alone, but I do not agree that this is DIY IMO. Regardless of 410A or not, you still can not legally release any refrigerant knowingly. There is no such thing as a safe refrigerant, only better for the environment than what was used previously. Such as.... you are still required a full evacuation of a 410A system same as 22 system, but I digress. Make your own call, but I don't think we should be giving this information in this type of forum, would be better suited for pro only setting.
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Old 02-27-2011, 07:25 PM   #19
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0 degrees superheat will ruin your compressor. Post suction and discharge pressures. Post liquid line and suction line temps. Post number on TXV.
Will also need to post ambient temp.
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Old 02-27-2011, 07:29 PM   #20
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i'm going to leave this alone, but I do not agree that this is DIY IMO. Regardless of 410A or not, you still can not legally release any refrigerant knowingly. There is no such thing as a safe refrigerant, only better for the environment than what was used previously. Such as.... you are still required a full evacuation of a 410A system same as 22 system, but I digress. Make your own call, but I don't think we should be giving this information in this type of forum, would be better suited for pro only setting.
So far. In none of his post has he said anything that he has or intends to release any refrigerant into the atmosphere.

This is no different then if he went to a store and bought a couple cans of R134A to use in his car.

All members here are free to use their own opinion/judgment of how much info/aid they wish to give or not give.
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Old 02-27-2011, 07:30 PM   #21
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i'm going to leave this alone, but I do not agree that this is DIY IMO. Regardless of 410A or not, you still can not legally release any refrigerant knowingly. There is no such thing as a safe refrigerant, only better for the environment than what was used previously. Such as.... you are still required a full evacuation of a 410A system same as 22 system, but I digress. Make your own call, but I don't think we should be giving this information in this type of forum, would be better suited for pro only setting.
Eventually. He might realize what he did that is causing the system to operate like this. He already told us in his postings what he did wrong.
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Old 02-27-2011, 07:39 PM   #22
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yes there is, EPA certification in US maybe not in canada................
To handle refrigerant in Canada, you need a certificate from Environment Canada, and to transport it you need another from Transport Canada. So, two certificates are required to purchase, unless you are going to use it in the supplier's parking lot .
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Old 02-28-2011, 11:53 AM   #23
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TXV and superheat


I'm assuming If your messing around with superheat and subcooling your not any regular Joe.

Remember to when you adjust your txv it may take 15 minutes for everything to even out.

Last edited by Hubcap626; 02-28-2011 at 11:55 AM.
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Old 02-28-2011, 01:22 PM   #24
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TXV and superheat


For anyone who is wants to know the outcome. I checked the system the next day. Temp was a bit higher the 2nd day. 75 vs 70. The TXV started adjusting the superheat properly. I don't know why. The super heat was still very low but I was able to increase it to 7 degrees. The only strange thing is that I now have gas bubbles in the sight glass that is right before the TXV. The subcooling is a bit high 12 and it should be 9. This would indicate overcharge but the bubbles would indicate undercharge.

I'm getting a good temperature drop 15 F so I'm not going to touch it.

For the non pros out there. If you assume that the liquid you feed to the evaporator is at the pressure you measure at the port. The you know that the boiling point of that liquid 410a in my case 50F in my case. So then you blow hot air across the coil and start heating the gas that was just created. To transfer heat from the coil to the air, air will cool down gas will heat up. Superheat is the measure of how much this gas has heated. If the superheat is 0 then you are not turning all the liquid to gas in the coil. You may get liquid going flashing to gas in your return line or worse liquid is still in the line. Liquid on the input of the compressor is very bad.

In summary. Thanks for your comments. It works now and I have no idea why. I'll check it again in the middle of the summer when there is a better load on the system.
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Old 02-28-2011, 06:11 PM   #25
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TXV and superheat


The last 410A class I went to said you cant use the sight glass as a charge indicator since it can bubble from the change in diameter.
Next time you go back set the subcool at the specified 9 and your superheat should rise.
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Old 02-28-2011, 08:51 PM   #26
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The last 410A class I went to said you cant use the sight glass as a charge indicator since it can bubble from the change in diameter.
Next time you go back set the subcool at the specified 9 and your superheat should rise.

I was kind of wondering if that was the case. In the sight glass it looks more like the bubble may form but then condense back to liquid.
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Old 12-30-2011, 07:27 PM   #27
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TXV and superheat


If you are getting low superheat measurements, you need to check a lot of things. What is the delta T across your evaporator? Do you have a low load on the evap? Is this the original TXV? Are you short cycling supply air?

Also, to charge a TXV system, you have to charge by subcooling. A TXV is designed to maintain a constant 15 degree superheat, regardless of low charge or over charge. Once you have charged to subcooling and can confirm your charge is right, you then check superheat to " troubleshoot" your txv

Last edited by ServiceTech; 12-30-2011 at 07:30 PM.
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Old 12-30-2011, 07:36 PM   #28
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There is no license required to handle refrigerant.
Hahahahahaha, really dude? EPA has a test for the conservation and safe handling of refrigerant, but I guess you already knew that since apparently the smartest man on earth
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Old 12-30-2011, 07:55 PM   #29
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TXV and superheat


Beenthere is a very smart tech. One of the most impressive that I have come across, but I agree with hvactech126. We should not give instructions in this area.
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Old 12-30-2011, 08:55 PM   #30
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TXV and superheat


I guess I never updated this post. Turns out I had a bad txv. I've had bad luck with them. I broke one by adjusting it to far and this one was bad. 3rd one worked fine all summer.

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