AC Coil Installation

Tim Miller · 07-10-2008, 08:08 PM

Can an AC coil be installed backwards on the unit. the unit is aged by some 12 -15 years and is a seperate unit connected to a gas furnace. I amsorry that I dont have a picture to illustrate the type of coil.
thanks for any input.
Tim

Similar Threads:

**Sal Castro** · 07-11-2008, 08:34 AM

The inlet / outlet orientation should not matter on most installations (horizontal) to the air flow. Of course flipping it upside down would create condensate drain issues on vertical A-coils or any coil assembly with integral drain pan.

**Sal Castro** · 07-11-2008, 08:39 AM

On a 12 to 15 year old unit, if you are having air flow problems, I would be willing to bet the coil needs a good cleaning, especially if filter maintenance has been negligent.

I have seen drastic improvements in capacity after a good cleaning. (Surface cleaning doesn't quite do it)

**Jerry Peck** · 07-11-2008, 09:13 AM

By the time you do a "good cleaning", which requires removal of the coil.

I always advised my clients to "put an extra $100 or so in and just have a new coil installed, by the time you pay to have the old coil cleaned, you still have an old coil which is not-as-clean-as-new, yet you have almost paid that much just to clean the old coil ... replace the coil with a new one".

Darrell Udelhoven · 10-12-2009, 01:10 PM

Originally Posted by Jerry Peck

By the time you do a "good cleaning", which requires removal of the coil.

I always advised my clients to "put an extra $100 or so in and just have a new coil installed, by the time you pay to have the old coil cleaned, you still have an old coil which is not-as-clean-as-new, yet you have almost paid that much just to clean the old coil ... replace the coil with a new one".

Also, ask if they want a more efficient thermostatic expansion valve (TXV) metering device on it.

Of course, if it is not a Scroll compressor it may also need a start kit. I wouldn't have an evaporator w/o a TXV refrigerant metering device on it.

**Ben Jones** · 12-21-2012, 07:46 AM

As others have said, for a horizontal unit the orientation of the coil (front to back) makes no difference. From an installation stand point it is often times more efficient to put the coil on "backwards" in order to get the line set to the coil on a more direct path.

An additional note about putting in a new coil versus cleaning. If the current unit is 10 to 15 years old, it is probably an R22 refrigerant type. A new coil could be put in; however, a decision needs to be made to go with an R22 coil OR and R410A coil. The refrigerants are not compatible. If a new R22 coil is put in and the condensing unit goes out next summer - then a new R22 condensing unit will have to be put in OR an entire new 410A system put in. R22 is getting VERY expensive compared to R410A.

The upshot to this thought process is either keep the current R22 running as long as possible - especially if it is not leaking or otherwise in poor repair OR go ahead and switch out system to a new 410A. Just food for thought!

Patricia Williams · 06-02-2015, 05:51 PM

I have a real problem and would appreciate your input. We have zoned heat and air. Last
week the downstairs compressr stopped running. The service person said it was on Freon,
but the problem was the coil. He said it was leaking Freon and needed to be replaced. It
was installed in 2003. I was given a quote of $2055 to replace it. HOWEVER, another
service person at Sears told us it could no be replaced unless we also replaced the
outside compressor because the new coils were not compatible the "older" compressors.

HELP!

- - - Updated - - -

I have a real problem and would appreciate your input. We have zoned heat and air. Last
week the downstairs compressr stopped running. The service person said it was on Freon,
but the problem was the coil. He said it was leaking Freon and needed to be replaced. It
was installed in 2003. I was given a quote of $2055 to replace it. HOWEVER, another
service person at Sears told us it could no be replaced unless we also replaced the
outside compressor because the new coils were not compatible the "older" compressors.

HELP!

- - - Updated - - -

I have a real problem and would appreciate your input. We have zoned heat and air. Last
week the downstairs compressr stopped running. The service person said it was on Freon,
but the problem was the coil. He said it was leaking Freon and needed to be replaced. It
was installed in 2003. I was given a quote of $2055 to replace it. HOWEVER, another
service person at Sears told us it could no be replaced unless we also replaced the
outside compressor because the new coils were not compatible the "older" compressors.

HELP!

**Jerry Peck** · 06-02-2015, 06:49 PM

Originally Posted by Patricia Williams

I have a real problem and would appreciate your input. We have zoned heat and air. Last
week the downstairs compressr stopped running. The service person said it was on Freon,
but the problem was the coil. He said it was leaking Freon and needed to be replaced. It
was installed in 2003. I was given a quote of $2055 to replace it. HOWEVER, another
service person at Sears told us it could no be replaced unless we also replaced the
outside compressor because the new coils were not compatible the "older" compressors.

HELP!

If you order a new coil based on dimensions of what will fit ... the coils might be different.

However, if you order a coil for a specific make/model ... then the coil should be an exact replacement for your older coil.

Now to the "newer" versus "older" coil difference - my understanding is that the "newer" R410A refrigerant coils are able to withstand greater pressure than the "older" Freon refrigerant coils - so it would seem to me that the main thing would be that it is a suitable replacement for the coil in your older unit, i.e., size, proper ability to transfer heat (Btu/hr rating per CFM air flow), tubing is of proper size same, etc., etc.

Hopefully one of our guys with A/C technician training will address it better.

**Jack Feldmann** · 06-02-2015, 07:16 PM

I would think it would be very difficult to find a coil to replace a 12 year old unit and not have a problem with mismatching old technology and new technology.

**Scott Patterson** · 06-03-2015, 05:52 AM

Call a small local HVAC contractor and get a third opinion…. At twelve years of age that system has had a good life and should be replaced…

**Jim Luttrall** · 06-03-2015, 09:16 AM

Originally Posted by Scott Patterson

Call a small local HVAC contractor and get a third opinion…. At twelve years of age that system has had a good life and should be replaced…

13 years old, don't spend much money on the old system. The average life expectancy in Texas is 12-15 years. The refrigerant compatibility issues are real and can create a problem and additional expense. The cheapest in the long run will likely be total replacement. Get the highest SEER rating you can afford. Check references on the installer. Sears is NOT the company I would trust with a central HVAC system since they likely just hire subcontractors to do the work and charge a bit more for their profit. Try to use smaller (mom & pop) companies with a good reputation in the area.