AC confusion

[Hillside]

When my 2 story house was built in 1987 it had 2 heat pumps for a split system. When I bought the house in 95 I had a Lennox Complete Heat installed. Lots of problems, of course (4 completely new units installed, I guess that's where the name comes from). Most recently the Lennox was replaced by a Polaris, which seems much quieter.
That is not my problem however. Over the years I have replaced my heat pumps with 10 seer Trane air conditioners; the one for the upstairs in 2002.
Yesterday not much cool air from the 2nd floor vents. Contractor came and said that there was a leak in the attic (the air handler is there) coil and that since a 10 seer coil was not available any more, he would have to put in a 13 seer and therefore a 13 seer outdoor unit. For the same price he could put in a 90 seer furnace in the attic and replace the ac units (I'm getting confused already).
So essentially I would be replacing a 4 year old outside unit for a new 13 seer. That bothers me.

My friend has a friend in who has an HVAC business and when I spoke with him he that he thought that a 10 seer coil for the attic should still be available. And even if it was not, he could put in a 13 seer coil in the attic (more confusion: he said that the 10 seer has a fixed orifice and the 13 seer has an expansion valve- I don't understand this). So he is checking to see if a 10 seer is available. Can a 13 seer indoor coil be installed with a 10 seer outdoor unit? This person also asked if the leak was in the AC coil or in the Aquatherm. I don't know, but contractor #! did mention an Aquatherm. I'm assuming that the leak was in the ac coil since I was not geting cold air.

Details: the outdoor unit is a 10 Seer Trand TTR025C
and the paper that I have for the attic air handler is Trane BWH724A100A1

I see no reason to put a new furnace (90% efficiency in the attic; and HVACer above said that there would be condensation issues with this in an attic.

Your advice will be appreciated.

[BaldLoonie]

You can use a new Trane air handler and have a Trane "quick start" kit added to the existing outdoor unit and all will be fine.

[aircooled53]

I would agree with the Old Bald one.
TWE024C140-Air handler with 10 kw heat package.

Not sure of the numbers anymore as things have changed in the past year and I sell Carrier now.

But, with the new air handler you would increase the 10.0 seer to maybe 11.0 and only need to add start kit for the txv-(thermostatic expansion valve).

As for a coil for that old of air handler you will pay as much for it as new air handler..

If your contractor doesn't want to replace the air handler call somebody else for bid.

[Hillside]

So let me clarify this. Are you saying that the 13SEER
coil in the attic is compatible with the 10 SEER outside unit?

And what about the issue of the availability of a 10seer
coil?

Thanks for your advice guys.

[iheatncoolinnc]

Details: the outdoor unit is a 10 Seer Trand TTR025C
and the paper that I have for the attic air handler is Trane BWH724A100A1

The BWH724A100A1 is an older style air handler than the TTR025C outdoor unit. This outdoor unit would probably work better with the newer style 13 SEER air handler than the existing older style air handler. The existing air handler was an 8 SEER from memory. You should increase the efficiency to at least 10 to 11 with the new air handler. A better match would be the 10 SEER air handler which should have been done when the outdoor unit was changed. This is another reason to match the system.
You might want to consider the new 13 SEER outdoor unit, due to the increase in efficiency and start with a fresh system. Has this system been sized by a Manual J load calculation? If not this might be a good time to start over and have a properly sized system.
The TTR025C is a straight air conditioner and not a heat pump. The heat pump would be a TWR02? model number for the outdoor unit.

[Edited by iheatncoolinnc on 08-29-2006 at 09:21 PM]

[BaldLoonie]

A replacement coil should be available but often are more expensive than buying a whole new air handler.

The new 2TEC air handlers will be fine with your existing A/C if a start kit is added. They have an expansion valve coil for higher efficiency and a recip compressor like you have and like the 13 SEER Trane units have, need this start assist to start against the TXV.

[tomac]

Wow, twenty years and all that trouble, and it's still not right? Sorry for your troubles and I can't add anything else, but that situation is terrible.