New 5Ton HP/AC/Trane or Carrier?

[Carry On]

The time has come to replace the 5T Carrier HP, about 9 years old, 10 SEER, due to leaks in the evaporator coil. Thought about replacing it a few years ago but put about a grand in repairs because R22 was being phases out and few were sure about installing R410 units.

1. I understand that it is now permissible to use the existing R22 line set if properly sized and flushed and our believe ours are. A few years ago no one sure about using the existing line set. Can the existing line set be used? Will a 3/4 inch condensate line be adequate with a higher SEER unit.

2. I prefer a scroll compressor for somplicity and note that Trane does not use them, whereas a few years ago it did? Is the preference correct?

3. We live in Florida and the AC stays on for long cycles? I therefore see no benefit to a variable speed air handler. Is that correct? And isn't is less reliable than a single speed air handler, subject to power surges and producing EMI in the house?

Look forward to all comments helpful to this decision. Thanks.

[JWB]

Trane XB13 units use scrolls. Great basic AC. I sell them all the time.

[BaldLoonie]

Trane uses scrolls in some models & sizes. The rest are the old recip.

Look at all the specs. SEER, EER, HSPF, capacity. Most Trane pumps are shy on heating output meaning cooler air and more backup. The XL15i is a notable exception.

[Starglow]

The time has come to replace the 5T Carrier HP, about 9 years old, 10 SEER, due to leaks in the evaporator coil. Thought about replacing it a few years ago but put about a grand in repairs because R22 was being phases out and few were sure about installing R410 units.

1. I understand that it is now permissible to use the existing R22 line set if properly sized and flushed and our believe ours are. A few years ago no one sure about using the existing line set. Can the existing line set be used? Will a 3/4 inch condensate line be adequate with a higher SEER unit.

Required line set size will depend on the equipment installed. Condensate line size of 3/4 inch should still be ok.


2. I prefer a scroll compressor for somplicity and note that Trane does not use them, whereas a few years ago it did? Is the preference correct?

Trane builds their own compressors from what I understand. Copeland makes the scroll compressors.


3. We live in Florida and the AC stays on for long cycles? I therefore see no benefit to a variable speed air handler. Is that correct? And isn't is less reliable than a single speed air handler, subject to power surges and producing EMI in the house?

The variable speed blower helps to remove humidity as the blower runs over a longer period of time on the slower speed. The blower motor has three electrical windings, one for each speed, but otherwise is no different from a single speed blower regarding reliability, power surge, or EMI issues which most consumers could care less about those things.

You may have to use a variable speed air handler to get a SEER rating high enough to qualify for the tax rebates depending on the required equipment combination to fit your application.

[FSHS]

Trane has been having too many problems with their txvs, I would truly investigate further & check their bulletins. between the two carrier would be a reliable fit (my opinion)

[Cold Feet]

The variable speed blower helps to remove humidity as the blower runs over a longer period of time on the slower speed. The blower motor has three electrical windings, one for each speed,

The whole point behind VS blowers is that they have a lot more than three speeds.

They have three coils because they're three phase motors.

[dan sw fl]

They have three coils because they're three phase motors.

What size and type AHUs are you talking about?

[Carry On]

Trane XB13 units use scrolls. Great basic AC. I sell them all the time.

Does Trane require a new line set for the warranty? My line set is 3/4 suction and 3/8 liquid? I'd be replacing an R22 5T with a 410 5T.

Can it be cleaned with RX11 without voiding the warranty?

I'd like to avoid installing a new line set for several reasons, not the cost: the existing line set goes up the side through a cover into the eve above the second floor and across the attict and down into a closet containing the air handler. I'd like to avoid messing up the exterior with a new cover and making the job more complicated since that just risks more problems.

Thanks.

[Carry On]

What size and type AHUs are you talking about?

It would be a 5T/410, replacing a 5T/R22. I am not looking for the highest SEER but the most reliable. In the past, I've read of EMI and circuit board problems with VS air handlers (they are less reliable), and it seems to me that in Florida they will run at full speed most of the time, just like a single speed air handler that I have now and therefore there is little benefit from lower reliability (greater complexity). In principle, VS is a good idea, especially for heating. But I doubt that the few minutes of slow start up time for dehumidification will make much difference with long run times like we have in Florida. My single speed keeps the humidity low; no complaints there.

[beenthere]

It would be a 5T/410, replacing a 5T/R22. I am not looking for the highest SEER but the most reliable. In the past, I've read of EMI and circuit board problems with VS air handlers (they are less reliable), and it seems to me that in Florida they will run at full speed most of the time, just like a single speed air handler that I have now and therefore there is little benefit from lower reliability (greater complexity). In principle, VS is a good idea, especially for heating. But I doubt that the few minutes of slow start up time for dehumidification will make much difference with long run times like we have in Florida. My single speed keeps the humidity low; no complaints there.
Many VS blower problems are installer created.

And the VS just gets an invalid bad reputation.

They are very reliable.

In Florida. If its an area of high humidity, then it won't be running at full speed all the time. And can prove to aid in more savings, by helping to control the humidity.

[Airmechanical]

1. I understand that it is now permissible to use the existing R22 line set if properly sized and flushed and our believe ours are. A few years ago no one sure about using the existing line set. Can the existing line set be used? Will a 3/4 inch condensate line be adequate with a higher SEER unit.
yes, and yes

2.I prefer a scroll compressor, Trane does not use them, whereas a few years ago it did?
you got it backwards on that one

Is compressor preference correct?
both style compressors are proven, so your preference is ok


3. We live in Florida and the AC stays on for long cycles? I therefore see no benefit to a variable speed air handler. Is that correct?
no

And isn't is less reliable than a single speed air handler
no

subject to power surges
everything is subject to power surges, most v.s. motors come with 10 year warranties?

and producing EMI in the house
just like any electrical device!



.

[Carry On]

Thanks. Didn't mean to be confusing.

When I check the Trane site, it is not clear which units are scroll compressors, except, I think, it's variable speed top end condensing unit. At this point, I'd like to simply replace my Carrier scroll, single speed system with same in Trane or Carrier.

[tigerdunes]

carry on

Trane does not have a qualifying 5 ton HP system for the $1500 tax credit.

Carrier does have several choices that do qualify.

IMO
Good Luck!

[catmanacman]

Thanks. Didn't mean to be confusing.

When I check the Trane site, it is not clear which units are scroll compressors, except, I think, it's variable speed top end condensing unit. At this point, I'd like to simply replace my Carrier scroll, single speed system with same in Trane or Carrier.

in the last 10 years i have found more bad scroll compressors than recip in the trane units the trane recip compressor is very reliable so i would not be concerned about a recip in a trane

[Starglow]

The whole point behind VS blowers is that they have a lot more than three speeds.

They have three coils because they're three phase motors.

Residential homes are not commonly wired with three phase electrical service.... if ever.

[Starglow]

Does Trane require a new line set for the warranty? My line set is 3/4 suction and 3/8 liquid? I'd be replacing an R22 5T with a 410 5T.

Can it be cleaned with RX11 without voiding the warranty?

I'd like to avoid installing a new line set for several reasons, not the cost: the existing line set goes up the side through a cover into the eve above the second floor and across the attict and down into a closet containing the air handler. I'd like to avoid messing up the exterior with a new cover and making the job more complicated since that just risks more problems.

Thanks.

Your current line set seems to be easily accessable for replacemeint and should not require a new cover when the old one can be reused.

I would opt for a new line set just to avoid any potential warranty issues down the road if the old lines aren't flushed properly. Installing a new line set is cheap insurance and seems fairly straight forward in your case.

[beenthere]

Residential homes are not commonly wired with three phase electrical service.... if ever.
He's not talking about 3 phase electrical service.

[Cold Feet]

Residential homes are not commonly wired with three phase electrical service.... if ever.

The motor control board in a VS blower system contains a three phase inverter.

[Airmechanical]

The motor control board in a VS blower system contains a three phase inverter.

actually, the module is the inverter

the control board makes decisions and sends signal to the 16 pin plug, based on the dipswitch settings



.

[Carry On]

actually, the module is the inverter

the control board makes decisions and sends signal to the 16 pin plug, based on the dipswitch settings



.

In a VS air handler with a single speed heat pump, does the blower operate at the same top CFM in heating and cooling?

[beenthere]

In a VS air handler with a single speed heat pump, does the blower operate at the same top CFM in heating and cooling?

On York it is. But the Speed/CFM for when a W signal is received is set separately. So it can have the same or different CFM.

And even with a single stage condenser. You can still use a humidistat to slow the blower for increased latent capacity.