Have 2 leaky evap coils.. Replace with same or go generic

pcumming · August 2010

Have 2 10 year old Comfortmaker (ugh) residential units-2 ton and 2.5 ton with gas Comfortmaker furnace on top.

No ice on coils. Last year my great and trusty hvac guy had to top off the R22. This year he has been out 2x to top off. One needed more R22 than the other.

This time he got out his leak detection meter (for R22) and found a leak in both evap coils, one more than the other. I was interested and watched him do this. *Tomorrow he will come out and check the outside condenser for any leaks-we ran out of time today.

A. Also tomorrow, he will get me a price on 2 Comfortmaker made replacement uncased downstream coils for my 10 year old unit.

B. He also mentioned that perhaps I could use a different brand uncased evap coils (Goodman/Aspen) could work with my Seer 10 condenser unit assuming they fit in the evap case. He said we would need a TXV valve and would need a 3/4 to 7/8 adapter or something. He also said that this would not make my units operate at a seer 13 level. These Seer 13 evap coils can handle R22 or R410A per Alpine: <a href="http://www.alpinehomeair.com/viewproduct.cfm?productID=453063169">http://www.alpinehomeair.com/viewproduct.cfm?productID=453063169

[color=#f98237]Since I am not working currently and been out of work for a while. I do not have the money to replace both AC units (and condenser) in their entirety-ie: 2 completely new systems.

But I was thinking that if I used these new coils (10 year warranty) with R22, that if the condensers went out in the future, perhaps I could go to a Seer 13 condenser and run R410A making things more compatible

Would this give me a Seer 13 unit or are there more factors???[/color]</a>

Since I am not working currently and been out of work for a while. I do not have the money to replace both AC units (and condenser) in their entirety-ie: 2 completely new systems.

But I was thinking that if I used these new coils (10 year warranty) with R22, that if the condensers went out in the future, perhaps I could go to a Seer 13 condenser and run R410A making things more compatible

Would this give me a Seer 13 unit or are there more factors???

Whats best to do: A, B and any comments you might have?

Thanks so much

Peter

<a href="http://www.amazon.com/ADP-13C30-Cased-Evaporator-17-5wx16-5hx20-5/dp/B003KWD5WA"></a>

ddlong1286@yahoo.com · August 2010

In writing

He needs to show you some paperwork from ARI to verify that upgrading to these coils will indeed give you 13 Seer. Ten year old units-don't think so, but if they where higher seer units, 11 or 12 seer when installed, then maybe a txv and new coils will get you to 13?

I agree that using the new coils gives you the option for 410a in the future. If you only have so much money, fix one and wait on the other. Heating season is quickly on the way!

Don in Mo

Eugene_Silberstein · August 2010

Replacing Part of a System

Any time you replace only part of a system, especially when you are not properly matching the components, you can expect the efficiency of the system to decline.

What makes a high efficiency evaporator a high efficiciency evaporator are typically the metering device used and the physical size of the coil. Evaporator coils are designed for use with R-410A when they are factory pressure tested at a minimum of 235 psig.

By installing an evaporator coil that is rated at 13 SEER, you are increasing the rate at which heat can be absorbed into the system. By leaving the existing condensing unit in place, you are not increasing the system's ability to reject heat. So, although the system may cool the space adequately, you will most likely NOT get any increase in efficiency. In fact, you might actually experience a reduction in efficiency.

Other things to consider are the length of the refrigerant lines that connect the indoor and outdoor units as well as the size of these lines. In order to achieve maximum efficiency, the line sizes must be appropriate for the equipment being used.

Ironman · September 2010

Using TXVs

Using TXVs may give a slight increase in efficiency (1/2 a seer. point at best). But if your cond. units have recip. compressors, then you will have to add hard start kits to them. If you're trying to keep costs down, use coils with pistons (orifices) instead of TXVs. Also, TXVs are refrigerant specific: You can't use an R22 TXV on an R410a system. Pistons work with any refrigerant, but may need to be re-sized when converting to R410a. The're very inexpensive. Make sure your tech. sizes them correctly. The one that comes with the coil may not be the right size. A 2 ton unit should be around 061 and a 2 1/2 ton about 067. That's the bore size of the piston in thousands of an inch. The size is stamped into the side of the piston.

Have 2 leaky evap coils.. Replace with same or go generic

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