He quoted Carrier 58PHA Boost 80 furnaces, paired with Performance 24ACC A/C units; Carrier shows the furnace having a "multi speed" ECM motorâ¦would that be the right pairing?

Is there a pairing in the Comfort series that would achieve the same?

What are the advantages of a multi speed motor? Does it really make for better comfort?

Thanks for the help!

Var speed blower motor is best especially for your climate with dehumidification.

The multi speed ECM motor is confusing to most homeowners. All it means is you have a fixed speed that is adjustable for various settings of CFMs/ton. The blower motor while high efficient is not var speed. It is very quiet though like the var speed and would be my choice if not going var speed.

If you give me the size furnace, size condenser, and evap coil Mdl, I will be glad to look up the AHRI numbers.

I would want the Edge thermidistat and also a filter cabinet if you don't already have one.

Post back.

IMO

House is one story, rooms total roughly 2,400 sf, with nine and ten foot ceilings throughout. Lot of windows, but have been replaced with very energy efficient Simonton vinyls (low e, argon gas, etc). I often work from home, so the heat/AC will frequently be on in the living areas all day.

Two Options

Option 1
Main Living Area
24ACC642 3.5 ton, using R-410A
CNPHP04821ALA coil
58PHA090-1-16 Boost 80 Furnace

Bedrooms
24ACC630 2.5 ton, using R-410A
CNPHP03017ALA coil
58PHA070-1-17 Boost 80 furnace
Edge t-stats
Both systems will have supply and return plenums, 4" filters, filter dryers. Both will also have duct work done (enlarge returns, and add two main trunks to supplies).
Total cost $15,560

Option 2
Main Living Area
24ABB342 3.5 ton, using R-410A
CNPHP04221ALA coil
58STA090-1-16 Furnace

Bedrooms
24ABB330 2.5 ton, using R-410A
CNPHP03017ALA coil
58STA070-1-17 furnace
Programmable t-stats
Both systems will have supply and return plenums, 4" filters, filter dryers. Both will also have duct work done (enlarge returns, and add two main trunks to supplies).
Total cost $12,600

So, assuming that these are all "proper", will the Performance system - over its life - deliver additional comfort and cost savings to warrant the extra $3,000 in cost?

This post was edited by mrjones on Tue, Jul 30, 13 at 10:53

I know it's Texas but 2 systems, 125 KBTUs of heating, 6 tons of cooling for 2400 sq ft.

Sounds oversized to me unless home has high ceilings and poor building, insulation qualities.

How were these sizes determined?

What size are you replacing?

IMO

The existing units are the same size: 3.5 and 2.5. As far as I know, they measured the rooms; explained to me that a ton is needed for every 400 sf. Afterward, I measured the rooms and came up with 2,400 (living area = 1,400; bedrooms = 1,000). Builder had said it was 2,778 sf, but that probably includes walls etc.

Not sure what constitutes high ceilings, but ours are 9' and 10' throughout.

I would not do this until you get a professionally performed load calculation.

The real Pros never ever size according to rule of thumb 1 ton/400 sq ft. Only HVAC old timers and hacks size that way.

Your sizing is ridiculous both heating and cooling.

How is your home's insulation properties especially attic?

It would be helpful to know the living area sq footage of each zone.

IMO

This post was edited by tigerdunes on Tue, Jul 30, 13 at 12:08

Not sure about the insulation details but I guess it would be standard for a house built in 1997. The attic has blown in insulation, the 2x4 walls have batting. All ducts are run through the un-conditioned attic.

I received bids form four outfits, all quoted 3.5 and 2.5 for one-stage systems. Three of the four quoted 4 and 3 for two-stage systems; the fourth quoted 4 and *2* for two-stage.

It would be helpful to know the living area sq footage of each zone.

IMO

Main Living Area (3.5 ton) is 1,380 sf (plus 30 sf in closets)
Bedrooms (2.5 ton) are 958 sf (plus 51 sf in closets)
These are by my own measurements

He just told me by email that he did do a load calculation.

Get the load calculation in writing. If it's not on the software letterhead and broken out by zone, it's worthless.

Any idea what design temps were used both for heating and cooling, inside temp and outside temp? Mighty important. A good dealer would have discussed this with you.

IMO

This post was edited by tigerdunes on Tue, Jul 30, 13 at 13:31

Will do. What sort of things are taken into account when doing a load calculation?

Size of rooms, building qualities, insulation qualities, ext doors, windows, directional orientation of home, shade, number of people living in home...etc

Design temps for cooling and heating
Inside temp and outside temp
Size to average not extremes

IMO

Besides the lower sound level TD mentioned (due to the compressor sound blanket), the Comfort series air conditioners have no external compressor protection (high or low pressure switches) and also do not have louvered outdoor coil protection. The new "Comfort" series models are the previous builder/base models. So from a sound/reliability/longevity standpoint, the Performance models are better. Given you are in the Dallas area and the units will receive plenty of use, I do suggest the Performance models (mainly for the high and low pressure cutoff switches to protect the compressor should unfavorable operating conditions arise as well as the better outdoor coil protection offered in the Performance line -- the lower sound is a plus as well).

This post was edited by ryanhughes on Tue, Jul 30, 13 at 15:51

We're in the Boston are and I just had an seer 13 Comfort series installed. Very nice unit, but the multi speeds are not user adjustable. Changing speeds requires switching wires behind the service panel. This is basically a one speed unit, it comes shipped set on medium and setting it to a different speed requires a service call.

The variable speed Performance series has the ability to self adjust, a higher speed when conditions need it and a slower speed once it has reached it's temperature setting. I wish I had gotten the Performance series for the simple reason that an air conditioner should run on it's slowest speed 90% of the time for economy and comfort, and only use the higher speeds when needed. Even in the NE area we have hot and cool days, and I plan to use this all year to circulate the heat from the fireplaces and filter the air.

I can attest to the fact that the Carrier Comfort series outdoor units are pretty noisy (the dB rating is not helpful as its a weighted average and perceived noise is very frequency dependent). They also use two blade fans which doesn't appear to help.

Ken: I think you are talking about the furnace/air handler whereas I believe the previous discussion is referring primarily to the outdoor condenser units.

Yes, right, I was talking about the fan coil, not the condenser. The noise you mentioned is outside and not bothersome to me, however I still would have preferred the upgraded unit. The ability to adjust the fan speed from low to high to suit the conditions is big. Today it's 96* and running fine on medium, but most days I would prefer it to run on low, and if your coming home to a hot house, and didnt leave the AC on, high would exhaust and cool the house much quicker.

I came across this post while looking to see if there are any recall notices on my Carrier Performance 16 unit. I've had this unit and its been nothing but an expensive headache every summer. In 5 years I've had to replace the coil, the txv, the compressor and every year I have to add refrigerant, and some kind of oil/gas mixture that must be added to the unit every 2 years because of the bad design of the unit. Hopefully you did not get this unit because the money saved on energy is nothing compared to the money I've shelled out to fix this unit.

Dwight, there is some irony in your post.

Carrier as well as Bryant are brands that are often recommended here along with Trane and American Standard these brands are touted here as something special than all the other choices you have.

There is no brand that's perfect. But there are brands with lower ownership costs. (It's not the aforementioned brands though)

You want to know why? You already know, but I will tell you: Money.

It's the old con game: My brand is better than your brand. Then the price of ownership kicks in. The costs to repair these brands are thru the roof.

Once the part warranty runs out, it's even worse.

This is why you can't trust everything you read on the internet from other homeowners offering what appears to be the golden apple.

I service the Katy, Texas area.

I don't know anything about AC units. This unit was recommended by the contractor who was doing the renovation work on our home. I had heard the carrier name all my life and when he recommended them I didn't see any reason not to go with them. We even upgraded from the model he previously recommended to the model we have now because it was supposed to save us money on energy over the course of the units life. When the unit is working, our AC bills are low even in the summer. When its not working, which is often, its very costly to repair. At this point, I am weighing the option of replacing the entire AC unit because it looks like its going to continue to suck money out of my wallet year after year. The AC person I have been using lately did some homework and found out that the design of this unit was just a bad design from the beginning by Carrier. I also found information on a class action suit against Carrier because my problems with this unit aren't unique to just me.

It looks like you are a profession HVAC company, what brand and model units do you recommend if I do end up going down the road of replacing this unit?

I'm not necessarily an 'equipment' seller. I am a HVAC retrofit repair specialist.

I do sell equipment but it is more about the goals of the customer, mixed with what I believe is the best fit to achieve that goal. ( I have used a combination of 8 different brands within the time my company formed a name on the side of the box means nothing.) The person working on it, maintaining it, servicing it --- means everything.

I sell more than one brand, I work on all brands. There is no perfect brand. If that is what you are looking for in terms of a recommendation --- no, concentrate on installation and service. The more cooks in the kitchen, spoil the broth in my experience. Or if you prefer --- turns it to corona soup.

To cut costs avoid the major name brands, if you can. While there is nothing wrong with any brand... what is wrong is what they charge for replacement parts. (they all offer 10 year parts, but if you hire a truck of clowns then expect someone like me to try to fix it after a bunch of clowns have manhandled it, you're not going to like what I have to say. There isn't much I haven't seen in 26 years of doing this. There is no warranty for improper installation.)

In some cases you can not get away from this: like for example you want to install a more efficient unit.

Now I could just tell you a brand I use, but due to the aforementioned criteria you just select anyone to install it and possibly with in a few years you may be in a worse situation than you are in now.

That's the way this game works (more or less) for the past 5 years or so. Every manufacturer is squeezing whatever they can from the units they produce. This increases breakage.... puts me in a good spot being a repair man.

You, not so much. You call someone up... what do you think they will tell you about their brand?

It's like moths to a bug zapper. The whole goal of an equipment seller is to more or less dupe you. Prove it to yourself... what were you told when you bought the Carrier?

Nothing has changed in that regard.

With that said, there is off brand equipment that is garbage. This is why you hire a pro and actually use said pro to install the equipment.

But money, what people perceive as a bargain 'up front' often turns into what you have now. Again 26 years doing this.

I service the Katy, Texas area.

"and every year I have to add refrigerant, and some kind of oil/gas mixture that must be added to the unit every 2 years because of the bad design of the unit."

Well, the design has nothing to do with the need for frequent refrigerant and oil "top ups". These are permanently sealed systems You have a leak and you need to find it and fix it. Could be in the outdoor condenser, the indoor evaporator or the lineset.

These are permanently sealed systems.

That's what they are supposed to be, but in as little as a year you may develop a refrigerant leak. It seems more and more that the average is trending down.

If you don't spring a leak you may develop a problem that mimics a leak. Those kinds of problems can be just as bad as if you developed a leak... because they will probably tell you that's what's wrong with it any way.

Any brand can suffer these problems and more.

I replaced a bad Lennox coil just over 3 years old. Had so many leaks in it, wouldn't hold freon for longer than couple of weeks. Sure the unit is under a part warranty... but as usual the builder didn't register it. Not like registering it is going to matter that much.

If the first coil failed in just over 3 years how long does the exact replacement last?

It doesn't end there.... Just a shade over 5 year old Trane...... well similar problem... but repaired it without much fan fare. Homeowner wasn't too happy except for the fact the air conditioner is working again in nearly triple digit heat.

Ah the life of an AC repair man. The manufacturer's make them, I fix them.

You could go out and buy a brand new shiny AC and suffer a similar fate. You will never get away from the repair man. (Knowledge Required)

I service the Katy, Texas area.