[wurdmann]

First let me say that I am not an HVAC pro in any way. I'm a homeowner trying to understand more about HVAC and what the best path forward is in replacing my current system. In doing my research I came across these forums and was hoping to get the opinions of those that are more educated than I am about HVAC. I apologize if this forum is not for these types of posts, but I didn't see anything forbidding them. Please kill the post if I am wrong. I have also posted this in /hvacadvice on Reddit. Here goes.

I am currently looking to replace the HVAC system in my house that is located in the gulf coast region. It's hot and humid most of the year, and when the temp drops below freezing it's treated as a weather emergency. The house is around 2200 sq ft. and was built in 1998. The ductwork and HVAC system are the original from when it was built.

I have three different estimates that vary substantially and wanted to see what the consensus was on the best way to go. One problem that I am trying to understand better is whether I need to replace the ductwork. One company said that it absolutely needed to be replaced, especially if I moved up to a 4-ton unit (currently have a 3.5-ton). I don't mind doing that if needed, but one installer didn't mention the ductwork and the other said it looked fine and ductwork lasts 30-40 years. This was after I asked him explicitly if new ductwork was needed. So, my questions are 1) replace the ductwork on a home built in 1998 while putting in a new system? and 2) which system looks best. Here are the options that I am considering. Oh, also all of these are 14 SEER units. I have estimates for ones that are higher SEER, but at a price that I'm not willing to pay.

Option 1: 4-ton Ameristar (10 year parts/ 2 years labor): $8500

Option 2: 4-ton Goodman Signature Series (10 year parts/ 10 year labor/ 10 year maintenance) + add new duct work: $18000

Option 3: 4-ton Carrier (10 year parts/ 1 year labor): $14,000

Also, to complicate matters Option 2 and Option 1 (I think) use aluminum and Option 3 is copper. Of course, they each insist one is better than the other. Also, some responses I received in another post on Reddit have questioned whether moving to a 4-ton was needed or warranted. I'm honestly not sure. From what I understand for this house size and region either would likely work. The only reason I was considering 4-ton units is it did not add much, and I didn't want to regret it later. The contractor giving Option 2 did offer a cheaper version where they put in a 3.5-ton unit and reseal the current ductwork for $15000

 

[peterphan88]

Are you in florida? i just replace my own 5 ton hvac system for less then $5k.

 

[peterphan88]

you don’t need to replace duct works.

 

[RoryDickerson]

It's great that you're doing your research and seeking out opinions from those more knowledgeable about HVAC. Don't worry, this forum is a perfect place for these types of posts.

 

[SamAllen]

I can't give you specific advice, but it might be helpful to get a few more opinions to see if there's a consensus on whether your ductwork needs to be replaced. As for the different options you're considering, it's understandable that you're trying to balance cost with quality. It might be worth doing some more research on the brands and specific models to see if there are any major differences between them. It can be helpful to check the following link https://www.onlytradeschools.com/hvac/.

 

[eggs]

Well, to start, I would NEVER purchase a Carrier product. They seem to be more expensive than others and the quality is not all that great along with parts are more expensive. As for the Ameristar, it is made by Trane wich is much better, but that is their bottom of the line version. The Trane brand is much better for a few bucks more. Goodman does give you a good bang for the buck, but is a mid line brand with parts at a reasonable price. As for the duct work - I do not live in that climate, but in the mid west, duct work lasts normally over 70+ years. Mine is fine and was installed in 1957. Next is upgrade from 3.5 to 4 tons - this is not an engine in your car. Bigger is not better - too big and you get cold wet air, too small you get warmer dry air. Thus sizing it is very important. A house build in 1998 should have 6" walls and well insulated with good windows - 2200 ft2 a 3 to 3.5 ton should be fine. On average - 600 ft2 needs 1 ton +/-. The air handler then needs to put out 400 CFM per ton. A 3.5 ton unit needs to push out about 1400 CFM. With a 4 ton, 1600 CFM - thats 15% more and most duct work set up for 1400 can handle 1600 with out issues, plus most air handlers that are rated for 4 ton, can push out 5 ton, enough to over come any issues. Next with out knowing what you have now, but most air handlers last a long time. The AC systems can last well over 30 years, unless damaged. If you are only changing because you want higher efficiency, pay back is many many years - not in my life time. If you are installing a heat pump, with electric heating elements, the air handler is more than likely OK. $8500 for the AC only is really high, with the air handler would be fair. So, personally I would get more quotes, stay with the 3.5 ton unit, keep your duct work. As for the different types of condenser coils, Trane's aluminum coil can handle a lot of dirt before issues happen and do last a long time but harder to clean Copper with aluminum fins get dirty easier in some areas, but works better in some climates. Nothing wrong with a 14 SEER, again, payback going to an 18 or 20+ SEER will take many years. In the Midwest, well over the life of the unit. The only advantage is possibly government kickback money. Good luck in your choice.