8 year old carrier replace/repair

[kilobravo3]

I've got a 5 ton Carrier Heat Pump (38YDB outside unit, FV4B indoor unit), that has developed an evaporator coil leak. I believe my system is fairly efficient already (unable to find my combo in the ahri directory), so I'm wondering what my best plan of action is here. The quotes I've received to replace the evaporator coil have all been in the same ballpark, so I don't think I'm getting taken advantage of, but it seems expensive just to replace the evaporator coil. I was given a quote on the Infinity 21 with Greenspeed, and it seems like a really nice unit. I'm looking for advice on whether I should replace the 8 year old coil (an only get a 1 year warranty) and hope for the best, or to go ahead and replace the entire system(and get the 10 year warranty). It seems like my system is at an age where either decision could be correct, and I'm just looking for advice on which route I should take. I live in North Fl if that makes any difference, and the cost to buy the Infinity 21 system is about 4x's the cost of the coil only replacement.

[second opinion]

I've got a 5 ton Carrier Heat Pump (38YDB outside unit, FV4B indoor unit), that has developed an evaporator coil leak. I believe my system is fairly efficient already (unable to find my combo in the ahri directory), so I'm wondering what my best plan of action is here. The quotes I've received to replace the evaporator coil have all been in the same ballpark, so I don't think I'm getting taken advantage of, but it seems expensive just to replace the evaporator coil. I was given a quote on the Infinity 21 with Greenspeed, and it seems like a really nice unit. I'm looking for advice on whether I should replace the 8 year old coil (an only get a 1 year warranty) and hope for the best, or to go ahead and replace the entire system(and get the 10 year warranty). It seems like my system is at an age where either decision could be correct, and I'm just looking for advice on which route I should take. I live in North Fl if that makes any difference, and the cost to buy the Infinity 21 system is about 4x's the cost of the coil only replacement.

8 years for a system is young, replace the coil. I would still shop around if the cost of the coil is 1/4 the cost of the 21 seer. I would not opt. for the 21 unless improvements in the air distribution systyem and the house envelope is addressed, otherwise you will be wasting money and will never see the higher efficiency.

[beenthere]

8 years for a system is young, replace the coil. I would still shop around if the cost of the coil is 1/4 the cost of the 21 seer. I would not opt. for the 21 unless improvements in the air distribution systyem and the house envelope is addressed, otherwise you will be wasting money and will never see the higher efficiency.

Or they're low balling the 21. And gonna cut corners.

[kilobravo3]

Or they're low balling the 21. And gonna cut corners.

I trust these guys. They are the ones that put in my system originally, and have a good reputation in our town. I haven't seen anything that would indicate that they have or will cut corners.

[beenthere]

At 8 years, I would generally recommend to just replace the evap coil.

[SBKold]

Is your unit R410a (puron) ?

Also I would wager a guess that you have considerable ductwork issues causing your 5 ton to only be delivering around 3.5 to 4 tons to the house.

I say that only because the vast majority of duct systems are not designed proper and a 5 ton takes quite a bit of thought to deliver true 5 tons worth or air.

[kilobravo3]

My unit is 410(a), and the duct work was installed when the current unit was installed (8 years ago when we built the house). I'm not sure how I would determine if there is inadequate duct work.

[SBKold]

It is not something even some contractors really know how to determine.

We could start by seeing photos of how the indoor unit is installed.

Also filter sizes and location?

[kilobravo3]

I know they did have to use some large flex ducts in my attic due to the way the trusses were designed. I have 2 main "trunk" lines going across the attic (supply and return) that are 16" in diameter (I think....I saw 16 written on the outside of the flex). I know flex is less than ideal, but unfortunately I think it was all they could do. I remember having the discussion with the owner of the hvac company regarding it. The supply flex line runs into some duct board, and then all the flex lines for the far side of the house run off of that. From the other suggestions, it seems as though it would be in my best interest to just replace the coil at this time since the remaining components seem to be functioning properly. I have one more contractor coming out for a quote tomorrow, and then I will make the decision.

[SBKold]

Was that one 16 flex supply and one 16 flex return?

[kilobravo3]

SBKold,

Your statement is correct. Those 2 flex lines feed the far side of my house (2 bedrooms and 1.5 baths). Each line runs across the attic to a duct board plenum? From there, each of the supply lines for the bedrooms and bathrooms branch out. Same for the returns. I'm not 100% sure they are 16", they may be bigger...I just saw 16 written on the ducts in several places.

[SBKold]

Pictures would definatley help. If that is the case you are ok for about a true 2.5 to 3 at best tons worth of airflow.

[tedkidd]

Pictures would definatley help. If that is the case you are ok for about a true 2.5 to 3 at best tons worth of airflow.

Good call. Looks like 16 rigid says 39,400, so flex probably is 2.5. What size/type of filter?

If your system is grossly oversized to your duct, this might be the great opportunity your intuition is telling you it is. (Love to see pictures!) You'll want to make the best of it and get size right.

5 ton GREENSPEED will flip out on that duct. That's the fun part of communicating equipment, crappy installs get exposed.

How big is the house? Can you describe how the old system performed on the very hottest days. Run time, noise, etc...

Be nice to know homes leakage. Be nice to know how much of the outdoors and attic you are cooling. Ever had a blower door test?

[kilobravo3]

I'm going to try and attach some images. I'll try to describe the setup. On top of the air handler is a "Y" where two 16" flex ducts are connected. The first split runs a short distance to a ductboard plenum(not sure if that is the right word or not, but it is duct board where all the flex duct feeds to each vent connect). This part of the split supplies air to 50 or 60 percent of my house. The 16" ducts in the picture are the ones that run across my unfinished bonus room and to the far side of the house. This supplies air to the remaining 40 or 50% of the house, and splits into a similar plenum as the one closer to the air handler.

I have a 4" aprilaire filter which I have updated to the most recent slide in filter type. The unit tends to perform well, although on super hot or super cold days, it does struggle to maintain or change the temperature. My electric bills have always been reasonable (I average about $250/month in North Florida in an all electric house with rates about .12/kwh, with a 2850 sqf house). The only room where we ever have a problem is my daughters room on the far side of the house with 3 exposed walls.

I've never had a blower door test done.

[beenthere]

A set of vanes in that return would help a lot.

[kilobravo3]

Beenthere-I'm not sure what that means. If I told my contractor that I would like to have vanes installed, I'm assuming they would know what they are? Also, what benefits do they provide?

[tedkidd]

I like the turning vane suggestion. Without bottom side or side side and 2 filters you are airflow challenged above 3 ton, and doesn't seem room for return modifications. (maybe uDarrel can confirm this) Unfortunately it feels like 3 ton might be too aggressive given your summary of current operation, unless the house has high leakage rate and/or good insulation opportunity that can bring load down.

4 ton might be the compromise you live with (and is probably what your restricted 5 ton was providing). A mod (vna) means it won't choke but for very hot days and if you ask for recovery. It'll probably exist around 2 ton most of the time.

By the looks of things you can afford good long term decisions, and sounds like thats how you already think. So can you research energy audits in your area? An understanding of leakage and load calc would be really nice, particularly with such tight sounding parameters.

[SBKold]

Not sure if anyone else sees poor transition to aprilaire. Not that you really could do any better. And with a 5 ton you would will still struggle with one aprilaire. Even though IMO it is the best performer in the airflow Dept.

Also please describe the ducts that hook to top of return riser and the indoor return grille set and do you run filters inside?

Also a very quick and easy static pressure test between air handler and that aprilaire would tell us a lot.

[kilobravo3]

The ducts on the return are similar to the supply, with a Y at the top feeding to two 16" flex lines. Those flex return lines hook up to 2 separate plenums (one on each side of the house). There is one large return (2'x2' maybe) in the main hall, another return of the same size in the living room, and then small returns (1'x1' perhaps) in each of the 4 bedrooms. I'm guessing the static pressure test between the air handler and the aprilaire is not something I could perform since I wouldn't even know where to begin as a homeowner. There are no other filters in the system outside of the aprilaire.

[Krzyd]

I've got a 5 ton Carrier Heat Pump (38YDB outside unit, FV4B indoor unit), that has developed an evaporator coil leak. I believe my system is fairly efficient already (unable to find my combo in the ahri directory), so I'm wondering what my best plan of action is here. The quotes I've received to replace the evaporator coil have all been in the same ballpark, so I don't think I'm getting taken advantage of, but it seems expensive just to replace the evaporator coil. I was given a quote on the Infinity 21 with Greenspeed, and it seems like a really nice unit. I'm looking for advice on whether I should replace the 8 year old coil (an only get a 1 year warranty) and hope for the best, or to go ahead and replace the entire system(and get the 10 year warranty). It seems like my system is at an age where either decision could be correct, and I'm just looking for advice on which route I should take. I live in North Fl if that makes any difference, and the cost to buy the Infinity 21 system is about 4x's the cost of the coil only replacement.

I would recommend the coil.