Mismatched HVAC equipment possible?


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Old 02-12-08, 07:46 PM
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Mismatched HVAC equipment possible?

Hello, poor homeowner here, with barely a clue...
Currently, I have an Arco aire, upflow 80% 100K BTU, with a 14 seer 3 ton A/C (NCP) with a A coil. A/C is in great shape only a few years old... Furnace is shot; Can I have the furnace replaced with a Carrier 58MCB 100K BTU unit and keep my A/C unit or will I have to replace everything?

Thanks for any and all help, I greatly appreciate it...

If you're wondering why this furnace, simply because father-in-law is in residential construction and can get this for cost(unfortanately he has nothing to do with HVAC)...
 
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Old 02-12-08, 08:08 PM
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You only need to replace the furnace...though running a load calculation (heat gains & heat losses) would be the best thing to do here, just to make sure that you get the right size furnace installed.

A tit-for-tat is not the best approach. What if the furnace you're replacing is oversized to begin with?

In this field, top operating performance happens when the installed system matches the house needs.
 
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Old 02-12-08, 08:16 PM
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Furnace sizing

I will second pflor's suggestion about doing a heat gain/loss calculation. There is a good program available online for doing this calculation. The cost to a homeowner is $49 & it will be the best $49 you spend on a furnace. Here is a link:
http://hvaccomputer.com
 
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Old 02-12-08, 08:24 PM
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No worries w/ that the 2 corporate companies that came out both were very insistant that even though the A/C works now in the long run a new 6 to 8K system will serve me better for the future... And both recommended 90K BTU systems, although they both did want to cut the air down by half a ton to 2 1/2...
 
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Old 02-12-08, 08:32 PM
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A/c

Personally, I think they are just trying to pad their pockets. In my area the average A/C system lasts 15-20 years.

90K is a lot of heat. Spend those $49 & find out what you need. You may find 2 tons of cooling would be ample. If that's the case, it might be worth it to replace both at the same time.
 
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Old 02-13-08, 01:00 AM
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Why were you told the furnace was "shot."? Furnaces are pretty tough --- usually the primary reason a furnace really needs to be replaced is that the heat exchanger is cracked or has holes in it.
 
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Old 02-13-08, 03:31 PM
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That's just funny, I'm in De, so I'm within 50 miles of you Grady!!!
My idea of shot parts and labor cost more than I paid for the furnace 10-12 years ago... Plus since newer unit is so much more efficient and will have a warranty, in my mind it just makes sense...

Thanks Guys
 
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Old 02-13-08, 03:58 PM
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Wink

Just slip the new furnace under the old A coil is all. They should be able to do it and not do anything to the AC at all .
 
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Old 02-13-08, 09:11 PM
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Hey guys will it make any difference if I go with a Trane instead of the Carrier?


Thanks again
 
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Old 02-14-08, 05:51 PM
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Brand

It will make no difference at all. Do your heat loss first.
 
 

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