Semi-OT: Air Conditioner Question

[Swingman]

As a single family residential builder, let me say that Ed gave you the best advice ... With central air go with installation and service.

Let me say it again: with central air, _installation_ is much more important than brand! :)

The difference between US brands is basically "fit and finish", as the parts that make it an air conditioner are pretty much universal off-the-shelf, with the exact same parts used by all brand manufacturers in the US.

IOW, forget the brand, go with a high SEER, 2 stage unit if you want the best efficiency and realized cooling, and make sure that your installer does a "Manual J" cooling-load calculation for your installation, preferably software based ... many free programs around if you want to double check yourself, like the following:

will cost you more for a properly sized, higher SEER unit 2 stage compression (about 30%), but I will guarantee you will make it back back many times over in energy costs over the life of the unit.

[Max]

We have a 5 ton Rheem. It's almost ten years old and hasn't "burped" even once. We keep the house at 75° F. 24/7.

Max (in *HOT* El Paso)

[Bob AZ]

Mark

A commercial building I am involved with, installed 9 each 5 ton Carriers last year. 2 have failed this week, 1 month after the warranty expired.

I have a Trane 4 ton unit, 19 SEER that as been faultless since new 9 years ago. Cheaper overall to run than an evaporative cooler in S AZ.

The house is super insulated and this is one of the features that keep my electric so low. $122 a month year around. All electric house.

Look closely where your proposed ACs are manufactured. Possibly all from the same factory in W Texas. Same machines but different labels.

Make sure the electric circuit is at least #8 wire with the correct circuit breaker. The name plate on the AC will call out the circuit breaker size.

Bob AZ

[Larry Jaques]

On Sat, 24 Jul 2010 00:06:47 -0400, "Ed Pawlowski" wrote the following:

American Standard makes toilets (OK, they started out with steam radiators), Rheem makes water heaters , and Carrier is an HVAC maker (Willis Carrier is the Father of Cool; he invented A/C.)

I found that I trusted Carrier more and bought a 96% efficient $6k Carrier HVAC system when I moved into this house. YMMV.

EXCELLENT questions, Ed. Rather than dumping a couple grand into refitting an old, dying system, swap it all out with new machines and ducting for a best-fitted house. The comfort alone is worth the cost, which might not be as different as one would think.

I saved about a grand by doing the wiring for the units myself. I ran a 10/3 Romex out for the condenser unit, installed an attic lighting string, and ran 12/2 Romex up to the evap/heat unit. This was my first high efficiency unit and I'm still amazed at the PVC exhaust tubing and the teppid air coming out of it when it's in full swing heating.

Good job!

-- Exercise ferments the humors, casts them into their proper channels, throws off redundancies, and helps nature in those secret distributions, without which the body cannot subsist in its vigor, nor the soul act with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711

[Larry Jaques]

On Fri, 23 Jul 2010 21:44:23 -0700, "Lew Hodgett" wrote the following:

Tell us about Liberal Algore's moldy money for his old Tennessee mansion, Lew.

-- Exercise ferments the humors, casts them into their proper channels, throws off redundancies, and helps nature in those secret distributions, without which the body cannot subsist in its vigor, nor the soul act with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711

[krw]

I bet not.

[krw]

Any words of wisdom on the mini-split units? From what I can put together these seem ideal for my use. I'm currently working on the space over the garage for my shop (I'll eventually turn it into another bedroom, when I sell). Instead of tying into the 2.5T upstairs unit (the downstairs has a separate 3.5T unit). I was thinking about a mini-split unit. The mini-split unit might even be easier than ducting the few feet (the air handler is in that space) and it would help keep dust out of the house.

[tom]

FWIW, there's a Rheem parts distributer in Tucson. That's one pretty good reason the local technicians prefer Rheem. Tom

[HeyBub]

See imbeded retorts.

I don't overlook it. Whether the oil industry gets tax breaks has not bearing, in my mind, over whether solar et al should get tax breaks. If you want to expand the discussion, yes, tax breaks for oil, gas, and buggy whips should be eliminated. The tax laws, in the main, should be used to raise revenue, not pick winners and losers in the marketplace.

You miss the point - I'm not opposed to innovation; I'm opposed to government defining the direction of progress.

Henry Ford did not get government assistance to re-jigger the production of automobiles nor did the American public get tax breaks to buy a Model-T. You can't name a nail-gun manufacturer who got government subsidies.

Agreed. But shouldn't it be a level playing field?

Huh? China is opening one coal-fired power plant per week!

If the providers of energy can supply oil at a cheaper price than we can produce it ourselves, yeah, we should buy from them. In a free market, however, they can't. Oil is fungible. If the world market is $80/bbl and we can produce oil profitably at $30/bbl, we're STILL going to be buying Saudi oil (because our local sources will be selling our oil to Japan).

As for "petro dollars to countries that fund radical groups," I remind you that Canada is our largest supplier of petroleum products, followed by (2009) Mexico. Still, you may be on to something; I've always been leery of the French in Canada (and Mexico was once ruled by the French).

One more clue: it is physically impossible to run this country off of sunbeams. A solar collector farm just to supply the energy needs of California (~50Gw) would be as large as the Los Angeles basin (some 1200 square miles). The only way to improve on this is to move the orbit of the earth closer to the sun.

As for energy independence, we Texans are in pretty good shape. We're not connected to either of the two national electrical grids, have a significant amount of oil and 70% of the nation's refining capacity. We also have more wind energy facilities than the rest of the country combined, and even two nuclear plants. We're lagging in hydroelectric, admittedly, but if solar ever becomes feasible, we've got a lot of cows that could benefit from the shade.

[HeyBub]

Come on! Gore passionately believes in warmed globals.

[whit3rd]

Air conditioners don't have legs. If yours has a bad compressor or leaks, or if a heat exchanger is damaged, why not fix what's wrong, instead of thinking it all has to be 'replaced'? Aren't there competent service personnel available in your area?

[Mark & Juanita]

Competent service person is the one who recommended replacement. Yes, the compressor can be replaced as can the squirrel cage motor that is going out, a couple of starting capacitors, and several other parts. That leaves the coils that may or may not be close to leaking due to the high vibration environment induced by the aging compressor. At this point, cost of service and replacement of those parts starts approaching cost of complete unit replacement. Complete unit replacement comes with higher efficiency and 10 year compressor and parts warranty == overall lower ownership cost that justifies the replacement.

Not making this decision frivolously, this is someone who buys and drives a vehicle until the wheels fall off and who will push the use of something well past its lifetime. Sometimes replacement is the best solution.

[Mark & Juanita]

Swing, thanks for weighing in here. I'm going with someone that, as best I can ascertain, will do the job right and stand behind what he has done.

Thanks. I'm trying to figure out why the Rheem bid is ~$900 lower than the Carrier unit. 1/2 SEER doesn't seem to be a differentiator in this case (14 vs. 14.5).

I think we are good with the loading since we are replacing 5 ton with 5 ton and no changes to the house that would adversely affect heat load have occurred. We can't go larger since this is a rooftop installation and 5 tons is maximum that we could put up. It would be cost prohibitive to re- plumb the entire installation.

I've looked into cost/benefit trades of the higher SEER units and can't make the transition cost-effective. We currently have a dual system (central evaporative, central air) system with barometric damper. I just replaced the evaporative system this year -- that I did myself, I won't / can't do the central air system myself. I want to keep the evaporative cooler because we really like the fresh airflow through the house when we can use the evaporative system. It works well here in AZ through about July when the monsoon hits and the humidity goes up. After that time, not so much. It is also nice having a dual system so that when one goes out, there is at least a temporary backup. Evaporative cooling may not work well in higher humidity, but it is way better than nothing, so redundancy is not a bad thing.

[Andrew Barss]

: Our air conditioner is on its last legs and will most likely not last the : summer -- it's 22 years old, so can't complain too much. The proposed : replacement is one of either, 1) 14 SEER American Standard, 2) 14 SEER : Rheem, or 3) 14.5 SEER Carrier. All of these are direct 5 ton replacements : for the existing unit.

: Has anyone recently gone through a replacement or had experiences (good or : bad) with these manufacturers? Looking for data points in multiple places, : and folks on this newsgroup have a diversity of experience with multiple : things, so am asking for input.

We replaced our quite old (I think it was installed in 1987) rooftop unit about four years ago. The new unit is a Rheem, and it works very well, and has needed no repairs since installation. I'd recommend it.

There are two issues we have, but one is due to where it's installed, the other with the state of our aged ductwork. Ours is a combined AC and furnace, and the blower/furnace/filter part is in a closet inside the house, with the coil on the ground outside.

Issue 1: The filter is electrostatic, and the unit had to be placed in the closet such that getting the filter out to clean it is a bit of a wiggle. And aligning the filter properly so one of the back corners doesn't drop inside the duct (i.e. getting it to seat properrly on its support) is a pain, as it's only a few inches off the ground, as mounted.

Issue 2: Our ducts (both intake and output) are just undersized for the house, so we have some circulation issues, and once in a while, if the filter is dirty and one of the intakes is blocked by something (i.e. a hamper of clothes), the unit can ice up. But that's not a fault of the unit, it's the house it's put into.

-- Andy Barss

[Andrew Barss]

This is a followup to Mark's question, with a couple questions of my own for Tucson folks. Our ductwork is really nasty --- some hard sheet metal, with who knows what sealing it (or failing to do so), and a lot of old, uninsulated, substadard and undersized flexduct.

Do you know anyone in Tucson who has a camera on a long cable that could snake it through the ducts and inspect them for leaks? We're concerned about both the integrity of the "real" ducts at the joints, and the shape of the flex duct (one pice of which we found completely disconnected a year ago).

And our regular HVAC guy is happy to redo all the ductwork, but not until the Fall, given the heat in the attic. Is this what I'd expect froom any HVAC guy?

Thanks --

-- Andy BArss

Andrew Barss wrote: : Mark & Juanita wrote:

: : Our air conditioner is on its last legs and will most likely not last the : : summer -- it's 22 years old, so can't complain too much. The proposed : : replacement is one of either, 1) 14 SEER American Standard, 2) 14 SEER : : Rheem, or 3) 14.5 SEER Carrier. All of these are direct 5 ton replacements : : for the existing unit.

: : Has anyone recently gone through a replacement or had experiences (good or : : bad) with these manufacturers? Looking for data points in multiple places, : : and folks on this newsgroup have a diversity of experience with multiple : : things, so am asking for input.

: We replaced our quite old (I think it was installed in 1987) rooftop unit about four years ago. : The new unit is a Rheem, and it works very well, and has needed no repairs since installation. : I'd recommend it.

: There are two issues we have, but one is due to where it's installed, the other with : the state of our aged ductwork. Ours is a combined AC and furnace, and the blower/furnace/filter : part is in a closet inside the house, with the coil on the ground outside.

: Issue 1: The filter is electrostatic, and the unit had to be placed in the closet such that : getting the filter out to clean it is a bit of a wiggle. And aligning the filter properly : so one of the back corners doesn't drop inside the duct (i.e. getting it to seat properrly on its support) : is a pain, as it's only a few inches off the ground, as mounted.

: Issue 2: Our ducts (both intake and output) are just undersized for the house, so we have some : circulation issues, and once in a while, if the filter is dirty and one of the intakes is blocked : by something (i.e. a hamper of clothes), the unit can ice up. But that's not a fault of the unit, it's the : house it's put into.

: -- Andy Barss

[Leon]

Our house originally had a Rheem and we had to have it worked on all the time. In its life time 14 years, we spent enough to have replaced it at least once.

Our current unit is 15 years old and still works well with only "1" switch replaced as a preventative measure and a fan motot and starter capacitor replaced.

What the AC guys have told me is to buy as cheap as you want, basically in the last 20 or so years government standards on containing leaking freon have gone up significantly. Basically the expensive repairs come in when the system leaks freon and oil. This has a bad effect on longitivity. Our

15 year old system has never needed freon added and electricity usage has actually gone down in the last 6 years. Yes I have data and charts to back that up.

Our current unit is a Goodman, manufactured in Houston. I'd buy again.

[Leon]

Air conditioners don't have legs. If yours has a bad compressor or leaks, or if a heat exchanger is damaged, why not fix what's wrong, instead of thinking it all has to be 'replaced'? Aren't there competent service personnel available in your area?

Effecency will never be as good as a new unit. Pay back will be sooner with a new unit.

[Swingman]

Which goes right back to what I said previously ... Goodman is also re-branded as "Janitrol" and "Amana" and is used by most builders in this area because they are inexpensive (but they indeed have the same generic components as ALL the higher priced brands).

(Mine two units are also Goodman, but I install mostly American Standard due to an excellent HVAC contractor relationship with one of the best installation teams around). I used to use Goodman also, but when my old HVAC contractor got sick and retired, I switched to the above mentioned.)

In a nutshell, a quality installation is what has got you such good luck with your Goodman. There is a perception that, being a 'builder brand', Goodman units aren't that great ... this is mainly due to the fact that Goodman will sell to any subcontractor who walks in off the street, and thus there are many, many substandard installs.

Once again, the major difference in central air brand names is the installation ...

[Swingman]

I forgot to mention that when I used Goodman, I spec'ed expansion valves instead of the flow rate tubes they come with, which may or may not be sized correctly by the installer for the particular install ... it makes a big difference in this humid climate to have a properly balanced refrigerant system.

Although I had to add an extra start capacitor on my Goodman units, it is also one of the reasons I can keep my AC at 80 and when you walk in from outside it feels much cooler than the actual temperature due to the lower humidity inside.

I'd bet that whoever installed your AC had enough snap to know the difference and/or knew how to balance the system with correctly sized flow rate tubes to get optimum evaporation in the condenser ...

Installation, installation, installation .... :)

[Robatoy]

I just had all my HVAC stuff redone. The installer walked me through my house and pointed a few things out to me which made perfect sense. I asked him point blank what AC ( I had already decided on the furnace) is best value. He suggested an nicely featured Amana as, like Leon pointed out, the regs need to be met. I went with this guy because of his rep as an installer. He put the same Amana in his house.... and considering the size and successes of his business, he didn't chose it because of the money. He then showed me, as a point of interest, the part numbers for the compressor motors on a Carrier, Lennox and Amana.....al the same motor. Like the good old days when you opened a Sony VCR and found nothing but Hitachi parts.... the Lambourghini Gallardo has an Audi engine... the Bentley a BMW mill....and a XC90 Volvo has a frikking Yamaha engine.