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Replacement AC question R22 vs 410a

Posted by a-louie (My Page) on
Wed, May 23, 07 at 17:49

I have a couple questions I hope you can help with.

1) Someone posted a link to Honeywell and answers questions on 410a, I cannot find again if you have it please post here.

2) I have had 5 contractors out to look at the house. None has done actual sizing. Look at what I have and listen to my issues. Summary below
- Current 2.5ton Whirlpool 22 yr old
- Live in Hot Atlanta
- Previous owners finished basement (mostly underground) at 1,200+ sq. ft and tapped into existing supply lines. No return in use.
- Main level I estimate at 1,900+ sq. ft.
- House is almost always in shade but has lots of windows. I plan to begin replacing this year in stages.
- Currently little to no airflow in house and it is not comfortable

Most companies have recommended going with 3 ton unit and using same 3/4" line set with R22. They cannot go any larger with R22 than 3 ton without replacing lineset and not easy to do.
One company says they cannot increase size at all with R22 but can go to 3.5ton with Puron/410A. If I used R22 I would have to have a 7/8" lineset. When asked why they went with 3.5 and others 3 ton he said when it is over 87 it will have to work much harder than 3 ton and did say it is not oversized.

Since I am replacing windows can I safely go with 3 ton unit and save the $500-$700?

3) Two companies said they would increase the airhandler a to improve airflow. Is that necessary? Others say once I add returns in basement that will resolve the airflow issue.

In summary I am leaning towards the 410a but not sure of sizing and the requirements on lineset. Can I increase AC size with current line by tring to save on the expense of 410a?

I have more quotes on Friday but want to be sure and ask the right questions. Any suggestions?


Follow-Up Postings:

RE: Replacement AC question R22 vs 410a

What is so special about using the same line set? If you skimp on line size, the system will not perform properly. Most 410 system require bigger line sets. Especially if you buy higher SEER than 13.

RE: Replacement AC question R22 vs 410a

Do you know how long your refrigerant lines are between the indoor and outdoor units? For a 3 ton unit you can go between 40' and 45' with 3/4" before you run into issues. I don't know why you would be able to go with a smaller line size with R410. Don't worry about R22 or R410. Either will work fine and R22 will be available for a very, very long time. Most airflow issues are due to ductwork not equipment. Has anyone checked out the ductwork to make sure it can handle a 3 ton unit? The air handler should be replaced no matter what size. Do you have a heat pump? Electric heat?

RE: Replacement AC question R22 vs 410a

The issue with replacing the lines is access. They are all hidden within finished drywall ceiling. Will replace if must but rather not tear into the ceilings.

The lines are about 30' long at most. Based on the amount of total square footage I am leaning towards the 3 1/2 ton unit. Is that still OK with the lines I have and length?

I am not sure why but two people have stated that the 410a can use smaller lines. If I stay with R22 I will need to increase the line size. I have been looking for information on line size requirements but not been able to find a simple easy to read chart. So I have been taking the sales reps word. I prefer to do my own research and validate what they say.

The ductwork is fine according to everyone that has been out. I will be replacing all equipment with new. AC, airhandler and furnace.

I do not have a heat pump and am using a gas furnace.

Leaninng towards the R-410a version.
Will be in the house for next 15 years, less to worry about
I read it is more effecient, not much I understand.
Due to the way they are made they should be more reliable

PS I was able to find the link on the myths of R-410a someone had posted.

Thanks for your feedback, I really appreciate it.

Here is a link that might be useful: Myths on R-410a

RE: Replacement AC question R22 vs 410a

One more question.

I have decided to go with a 3 1/2 ton unit instead of the 3 ton unit. I suspect some quotes used 3 ton to keep price down.

I called one of the companies that quoted the 3 ton and asked for a quote on the 3 1/2 ton unit. He told me one reason he stayed with 3 ton was due to sounds level. The larger unit will be louder from the blower. The product is a RUUD. It is located in a storage room directly behind the bar in the basement. This is a favorite hang out when we entertain and already is noisy there with refrigerator and kegorator compressors running.

Is he right will it be much noisier? If so what can be done to dampen the noise?


RE: Replacement AC question R22 vs 410a

Most systems that I have seen with 410, are higher SEER units. The newer units require a LARGER lineset. I do not install 410 systems. My partner does regularly. At some time, when 410 systems are designed better, I will start installing them. Or when 22 systems are no longer sold.

Noise is usually determined by fan speed and the design of the fan housing. If the fan is installed wrong, it can be quiter. If a motor is slower, the fan can be quiter. Different brands and models within the brands have less noise. It has nothing to do with size of equipment, in most cases.

To reduce the noise, hire someone who knows how to install the job correctly.

RE: Replacement AC question R22 vs 410a

Bob is wrong as usual.410a units have SMALLER lines than r22 units.Higher pressure and smaller lines.

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