A.C Coil Brand and Recommendation

[jw31bn]

I want to change this 20 year old a.c coil. What brand, size and other things i need to make sure before ordering it. Having a HVAC tech installing it for me. Here’s pics of the old one

 

[pjones]

Existing systems are notoriously oversized. An over sized unit can have multiple negative effects on the function of the whole system. I suggest having a proper heat load calculation done to see if your existing system is correct. Size your new system based on the results, if you need to reduce the size them you may need to change your furnace section also because the fan speeds may not be comparable for bother heating and cooling (either overheating in heating mode or pulling moisture off the coil in cooling mode, depending on how the fan speed gets set up in the end). If you need to get a bigger unit then that could mean increasing your ductwork to allow for he new larger airflow requirements.... speaking of airflow. New systems are often not comparable with old ductwork. Old systems use high temperature low volume air where new systems typically operate with low temperature high volume air. This can cause noisy ducts, motors to burn out prematurely, system operation issues, etc... the tech that calculates your heat load can also look at the ducts and help determine if you will run into issues with your new install.

I don’t do residential very much at all anymore so my experience now is limited mostly to commercial equipment aside from the units I’ve installed for friends and family, technology has changed a lot since I’ve worked in the residential sector. I like York units because parts are readily available in my area and they are easy to service. I’ve found Trane and Lennox parts to be vastly more expensive and often require a wait time to get. I don’t like the quality of Goodman very much, I’ve been happy with Carrier units as well, Bryant is basically a carrier but rebranded for non carrier certified dealers to purchase.

Has your current unit failed or are you replacing it preventively?

 

[jw31bn]

It’s not failed yet, but the inside coil is starting to have frost on it, so I’am thinking it has a leak somewhere. I don’t have the money for a whole new unit. So i was going to purchase a coil myself and I’am a tech install it. What’s your thoughts?

 

[pjones]

It’s not failed yet, but the inside coil is starting to have frost on it, so I’am thinking it has a leak somewhere. I don’t have the money for a whole new unit. So i was going to purchase a coil myself and I’am a tech install it. What’s your thoughts?

Newer units have higher SEER ratings. It will affect how the system performs if it’s not matched to your condenser. More of a problem if it’s a heat pump, but it looks like your unit is AC only so manageable, but you may lose your ability to remove humidity.

A frosted coil can be the sign of many different issues, refrigerant loss is only one of many possibilities.

Check your air flow (clean filter, blowers belt in good shape, blower wheel clean, floor registers all open, return air not blocked, evaporator coil clean on BOTH sides, blower motor capacitor providing proper capacitance, etc..)

What outside temperature do you run your AC at? If it’s too cold outside then it could be dripping down your head pressure too much causing the iced coil.

Filter dryer blocked up or restriction at the metering device can cause it also. Where exactly is the frost starting to form?

20 years is an old system but my concern is replacing the evaporator may not fix the issue, or the leak if it’s leaking at the condenser or somewhere in between. It may be cheaper to fix the issue than throw a dart at the evap coil.

It’s true what they say. They don’t build it like they used to. Everybody now wants high efficiency but they don’t realize that more often than not those systems have shorter lifespans and higher maintenance/repair costs. The overall savings in my opinion is debatable.

 

[jw31bn]

here a picture. New filter and cleaned off coils. The repair guy but Freon in it last year. Does Freon leak out running or off. What you thinking

 

[pjones]

View attachment 21855here a picture. New filter and cleaned off coils. The repair guy but Freon in it last year. Does Freon leak out running or off. What you thinking

If he put gas in last year for the same symptom and the symptoms disappeared after he added it then it probably has a leak. Either you or they would need to leak check the whole system to determine where it is leaking from. Dish soap on a small sponge then go to town over all the lines. Pay particular attention to threaded fittings, caps, and any place where the pipes contact anything else that could wear through.

Leaks don’t care if the system is running or turned off. If it leaked out since his last visit then he didn’t find the leak. Technicality they are not allowed to add more refrigerant at this point until they find and fix the leak. That may mean tightening a fitting, replacing a pipe, or if the coil is leaking then fixing or replacing the coil. I’ve seen coils become riddled with pin holes, there’s no guaranteed fix for that. If a capillary tube on the coil has worn through then that is an easy fix. Gotta find it first to know what you are up against.

 

[jw31bn]

Looking at that coil, does it seem like this one is gone.

 

[pjones]

Looking at that coil, does it seem like this one is gone.

Unfortunately it not possible to tell by just looking at it. You need to find the leak and that will determine what needs to get fixed or replaced.

 

[jw31bn]

Is the most common leak, the evap coil

 

[pjones]

If I had to pick a most common area for leaks I would say threaded fittings.

Doesn’t mean yours will fall within that category, every system is different.

 

[Jim greengo]

Do you have the model number off of outside unit so we can make sure of size coil you need?
Biggest thing is to get a coil sized for the tonnage of outside unit,and to match the width of existing coil so it will fit existing plenum.
Make sure your new coil is a 410a coil so you can reuse it if you upgrade to a 410a condensing unit outside.
Your installer can modify lineset and drain as needed.

 

[jw31bn]

I might just by a new coil and and condenser unit and let a tech install it for me. Can u tell me the size of my old coil by looking at the label on it. Here’s the pic

 

[Jim greengo]

It looks like 3 1/2t by the numbers on it,I'd like to see model number off of outside condensing unit also to be sure though.

 

[jw31bn]

The number are faded away , the only can i have it this back pic