Need To Upgrade

[royto]

First time poster.

Finally need to replace residential split system. CAC/LP, forced hot air.

Janitrol furnace (which is ok), Goodman A/C (10 SEER) (Model U-30, 2.5 ton)

I was considering moving up to a York 3.5 ton, 13 SEER system (Model PC48C3XN1).

1900 square foot house, not including the basement.

Long story short, how much trouble is this going to be?

Preemptive thank you for any responses.

royto

[cmajerus]

1st off why would you upsize the tonnage, what facts do you have showing you need a larger unit? If you have your contractor do a load calculation on the home you will be assured the unit is sized properly for the application, and oversized system will likely perform worse than the one you have now if that is the size you are supposed to have.
The installing company should be able to provide you with this information, or you don't want them installing it in the 1st place.

[royto]

Thanks for responding.

I have a guy that has services my business, as well as the home. Albeit, he was not the original installer, he was just out a few months ago to charge the system. (already knew the unit was leaking, trying to get through the summer)

He actually made mention, when I decide to change out the system, I should consider increasing capacity because he felt the builder was on the margin using a 2.5 ton unit.

As well, I am looking to add an addition in the future, it seems reasonable to have some reserve capacity.

I'm open to all suggestions. I have a working knowledge of this stuff, but for the finite information there is no doubt in deferring to the professional opinion.

[hangfirew8]

Janitrol furnace (which is ok), Goodman A/C (10 SEER) (Model U-30, 2.5 ton)

I was considering moving up to a York 3.5 ton, 13 SEER system (Model PC48C3XN1).

1900 square foot house, not including the basement.

Long story short, how much trouble is this going to be?

A lot of trouble, ripping out all the ductwork and putting in new just to properly accommodate a 40% larger system.

The contractor did bid that too, didn't he?

When the system worked well, did it cool OK on hot days?

Oh, and by the way, contractors adding coolant to your system doesn't always mean it is leaking.

-HF

[royto]

Thanks for responding.

I had him do a leak check, and I was told the evaporator coil was going, as well as the detecting leaks in the condenser. The system if I recall, was a 1997 model, with installation in 1998.

As for cooling, yeah, it was ok, but a definite difference between the first and second floors. Second floor always seems a bit warmer, (sure, heat rises) but it always seemed just a little insufficient to me.

Obviously, if I had the knowledge or the option to go back 10 years, I probably would have chosen to zone the floors, but I admit up front, I am approaching this without the knowledge of the majority of the folks here.

A couple of months ago, starting the season, I got the frost on the lines going into the coil, as well as the condenser.

He charged it, it worked great just until this Wednesday.

Frosted again.

[hangfirew8]

As for cooling, yeah, it was ok, but a definite difference between the first and second floors. Second floor always seems a bit warmer, (sure, heat rises) but it always seemed just a little insufficient to me.

Adding a ton won't fix anything about floor heat differentials. It may will increase the differential.

Even if you add zoning, or perhaps just more air returns in the upstairs, oversizing the A/C won't help. It will just short-cycle, die young, and leave the upstairs warmer then the downstairs. You'll have the option of turning the state way, way down, cooling the upstairs and turning the downstairs into a meat locker.

Short of zoning, adding returns, rebalancing the suppy, adding radiant barrier and/or insulation will all help with upstairs/downstairs temperature differences.

-HF

[hangfirew8]

Oh yeah, ask for the results of his Manual J to show cause for 3.5 tons, and his Manual D to show that your current ductwork can handle the necessary airflow.

Otherwise your oversized unit may suffer the dual fate of short cycling/short lifetime, and struggling against an undersized duct system (again, short lifetime).

-HF

[royto]

So for a single CAC system, you like the idea of retrofitting a zone capability?

I have been looking at this, but my guy said he was not a fan of the dampers because, (IIRCC) it could lead to a false differential in the returns.

He actually suggested having another system in the attic, thus separating the floors, and creating the 2 zones.

I am ok with this idea, but obviously I am here, trying to become a better consumer, in consideration for not only a broken system now, but perhaps a zone upgrade in the future.

Seriously, thanks for taking to the time to discuss this.

[royto]

One more thing.

I'll be upfront. He only suggested increasing capacity.

The unit I referenced in the beginning, is a unit someone informed me was a used unit for sale which is only a year old, because the owner opted for a heat pump one year out from his new home build.

Having the feeling I might need a new system, is my reason for being here now.

[hangfirew8]

So for a single CAC system, you like the idea of retrofitting a zone capability?

No, I never said that. IMHO zoning should only be done if a.) you have some real challenges to heat/cool a single house with a single unit and b.) you have a contractor that has done it before, done it often, and done it right.

Like I said, you can often lower the temp differential in a home by cheaper methods- such as addressing balancing, return size, higher flow return grills, more open diffusers, adding returns, adding radiant barrier and/or attic insulation, sealing existing duct, etc.

I have been looking at this, but my guy said he was not a fan of the dampers because, (IIRCC) it could lead to a false differential in the returns.

So, you clearly don't have b.)

Never push a contractor beyond their capabilities. Just get another.

He actually suggested having another system in the attic, thus separating the floors, and creating the 2 zones.

I am ok with this idea, but obviously I am here, trying to become a better consumer, in consideration for not only a broken system now, but perhaps a zone upgrade in the future.

I guess I'm having a problem discerning what is the real issue here. The original question involved fitting a 3.5 ton where a 2.5 was. Unless the builder oddly sized ductwork for a 3.5 ton, and then accidently installed a 2.5, I think that is a bad idea.

Now what is the real problem, besides replacing your old 2.5, do you just need a new working system, or do you also have a real problem with the heat differential between floors you are trying to solve at the same time?

-HF

[hangfirew8]

I'll be upfront. He only suggested increasing capacity.

The thought just occured to me, he might have suggested increasing capacity because he just got burned on wrong-sizing a York 3.5 ton, was forced to refit with the proper size, and now has an extra 3.5 ton he wants to sell.

-HF

[royto]

No, I'm being honest with you.

The unit I'm referring to, is totally not connected to this guy.

Something engaged on my own.

Months ago, he only suggested thinking about increasing capacity.

Never mentioned 3.5, etc.

Purely my own interest for the York system. Came across it by happenstance.

[royto]

No, I never said that. IMHO zoning should only be done if a.) you have some real challenges to heat/cool a single house with a single unit and b.) you have a contractor that has done it before, done it often, and done it right.

Like I said, you can often lower the temp differential in a home by cheaper methods- such as addressing balancing, return size, higher flow return grills, more open diffusers, adding returns, adding radiant barrier and/or attic insulation, sealing existing duct, etc.



So, you clearly don't have b.)

Never push a contractor beyond their capabilities. Just get another.



I guess I'm having a problem discerning what is the real issue here. The original question involved fitting a 3.5 ton where a 2.5 was. Unless the builder oddly sized ductwork for a 3.5 ton, and then accidently installed a 2.5, I think that is a bad idea.

Now what is the real problem, besides replacing your old 2.5, do you just need a new working system, or do you also have a real problem with the heat differential between floors you are trying to solve at the same time?

-HF

Yes. Replace what is not working now.

Curious about the effort to replace, would it be better to increase capacity, or just get the next generation 13 SEER 2.5 Goodman, or take advantage of a one year old used, and upgrade when I put on my addition?

Really, just trying to be pro-active, and perhaps prioritize future upgrades with the effort now.

Again, thanks for all of you input, it has surely opened my eyes more, and given me plenty the think about.