Heat Pump is vintage 1979 - time to replace??

[davefr]

Background:
My air handler/evaporator and heat pump (Carrier 4 Ton) is vintage 1979. The heat pump seems to be performing below baseline. I characterised the entire system several years ago just so I had a baseline for comparison. At 40 degrees outside ambient it used to give me about 20-25 degrees heat rise from cold air return to the heat vent closest to the air handler. (w/aux. resistive elements off). Right now I'm getting about 13-15 degrees. I cleaned evaporator/condensor, replaced filter, and oiled the air handler motor and am sure air delivery is fine. I suspect refrigerant charge has fallen a little below normal over the years. However the temp of the suction line where it enters the air handler is 150 degrees which is approx. the same as my "known good" baseline measurements.

I will probably have someone come out to check refrigerant charge but it's probably time to replace the entire system.

Here are my questions:

1. For a new system should I go R22 or Puron?
2. My lineset is about 75' long. I can relocate the condensor pad to shorten the run to about 40' but prefer not to. Is there much efficiency gain reducing the line set run?
3. Yes, I know that getting 3 bids, getting a manual Load J, and getting a good installer is more important then brand of unit. However are there component brands that should be avoided or given preferrence?
4. I know that the match between condensor and evaporator is key but is there merit in replacing the air handler? (the blower and aux. resistive elements are fine).
5. Any other tips in finding a good contractor? I don't know anyone that's had HVAC work done lately. (competance trumps cost IMHO)

[Furnace_dude]

replace them both. you cant get todays efficiencies with old equipment

[dash]

Heat pumps are near the grave as teenagers,so it's time,and there's energy to be saved.

1.Check out http://www.410a.com for yourself,I'd go Puron.

2.If the lines are sized correctly for the length,ask your contractor,I wouldn't move it.

3.If you want the tops in indoor comfort,use the search funtion on this site,for Infinity and Evolution,and see what other home owners have to say!

4.The air handler air flow capacity is based on the coil it can with from the factory,so go with a new air handler.Plus go with a variable speed indoor fan for energy savings and added comfort,when using great contol systems.

5.look for contractors on http://www.natex.org , http://www.acca.org ,at your choice of manufacters websites,BBB,etc.. Call around tell them you want a ManualJ,S,and D,to size,select,and verify duct design.If they say they can and will do it,that's a good start,if not keep dialing,IMHO.

[heatpumpguru]

Post where you live and we help you find someone!!!!!!!!!

[davefr]

Washington County. West side of Portland, Oregon.

[dan sw fl]

Originally posted by davefr
Washington County. West side of Portland, Oregon.

Home Comfort Heating & Cooling
2712 NE 3rd Pl
Hillsboro, OR 97124

(503) 640-8638

[smokin68]

1. Your choice.....either is fine IMO, as people aren't going to get caught with their pants down like r-12.

2.Not enough to warrant moving it.

3. In today's disposable society, focus on warranty/features,rather than brand IMO. A V/S airhandler is preferred. Remember, the more bells and whistles, the more things can go wrong, and higher repair costs.Really recommend extended warranties(from manufacturor) on these units, and I normally don't buy them(ex-warranties).
4. Go all new, not much difference($$$),and a known matched system.
5. Call your local hvac supply house, and see if they can direct you to a competant company. Get references from said company on systems 5+ years old.

[bing0]

According to the cursory research that I have done:

R-410a has many disadvantages.
There is one rather glaring disadvantage that I will leave for last as it has not been mentioned anywhere else on-line that I have seen.

R-410a (Puron) is still very much in development and manufacturers openly admit that it becoming the final solution for the replacement of R-22 is uncertain.

R-410a is also very hygroscopic which means that water or moisture in the air is absorbed into it like a magnet. Water is a big problem when it is in a closed refrigeration system.

R-410a, when in a system that develops a leak whether from physical impact or any other failure requiring a recharge, is extremely expensive to replace when compared to R-22.
A system recharge requires multiple evacuation and purging and additional filters and driers as well (moisture again).
This equals time and money.

Finally, R-410a operates at much higher pressures than R-22.
Currently 4 or 5 years down the road evaporator coils develop leaks with R-22 and proper installation.
Apparently the higher heat transfer efficiency requires thinner walled metal. This and the pressure in the system can expose production flaws that result in leaks at a much later date.
If this is true even of better manufacturers like Trane (though less so with Trane) with systems using lower pressure R-22, what is the outcome going to be with those systems which currently use R-410a?
Trane Factory reps admit that currently nothing is different in the evaporator coils of systems which use R-410a.

Only time will tell but, for me, with all of these major question marks, I am only going to use R-22 for my replacemnet system.

My layman's .02

Bing0

[Edited by bing0 on 11-03-2006 at 01:08 AM]

[dash]

We have been installing Puron/R410a since the late 90's,leaks are not a problem.

Copeland reports that the Puron/R410a compressor has the lowest failure rate of any residential compressor they have ever built.