Replacing a 4ton with a 5ton, what else should be replaced?

[trentc]

Built a house in July. House won't cool properly (indoor temp wouldn't get below 78deg during the day this summer and bedrooms are 2-4degs hotter than living area).

After months of arguing, found out that the HVAC sub-contractor made an error in their load calc (left out a bunch of west-facing windows)...orig Heat Gain was 45kbtu, corrected Heat Gain is 53kbtu. So, they agreed to replace my 13seer 4ton Goodman with a 14seer 5ton. Found out from Goodman that to use the 5ton with my existing air handler(AHU), the AHU needs a (thermal expansion valve) TXV and a my compressor needs a hard start kit (capacitor).

Thats the background...so my questions are:

1. What happens if the HVAC contractor does not install the TXV or hard start kit? (They claim its not needed.)

2. What happens if the existing duct-work in my house is too small for the new 5 ton unit? (I assume it is sized for 4ton since that is what I currently have)

[Roadhouse]

Okay, the air handler is being changed but not the condensor? And what is it that is not needed, the txv or the hard start, if not installed.

I'd get them to replace that condensor to match that 5 ton 14 seer air handler, no if ands or buts.

Good Luck.

[trentc]

They said they are only replacing my outdoor unit...from 4ton to 5ton but keeping my existing air handler.

The contractor says they will not add the TXV or the hard start kit...but the Goodman product description for the 5ton calls for both when used with my air handler.

[trentc]

The air handler is not being changed...the condesor is. The air handler will work with both 4 or 5 tons.

[MicahWes]

This is a new house and needs 5 tons? It must be a huge house with no shade, vaulted ceilings and tons of windows? I would have someone competent make sure that the existing unit is performing to its full potential, and that there are no building envelope problems that you don't know about before I went and started replacing equipment.

[Roadhouse]

They said they are only replacing my outdoor unit...from 4ton to 5ton but keeping my existing air handler.

The contractor says they will not add the TXV or the hard start kit...but the Goodman product description for the 5ton calls for both when used with my air handler.

Do you readily have available the model number for that air handler? Does it have '4860' in the model number?

[Stamas]

They said they are only replacing my outdoor unit...from 4ton to 5ton but keeping my existing air handler.

The contractor says they will not add the TXV or the hard start kit...but the Goodman product description for the 5ton calls for both when used with my air handler.

In the scheme of things this is a minimal cost on their part and if they miscalculated as you said it would be a minor thing that could alleviate the whole matter.

[Roadhouse]

This is a new house and needs 5 tons? It must be a huge house with no shade, vaulted ceilings and tons of windows? I would have someone competent make sure that the existing unit is performing to its full potential, and that there are no building envelope problems that you don't know about before I went and started replacing equipment.

Down here in Houston where all things are attic, you will on average find it 500 sq ft per one ton. Not oversized either, no humidity problems.

[trentc]

Air handler- Goodman ASPF426016B.

They said that are installing a Goodman SSZ140601A Heat Pump

[trentc]

This is a new house and needs 5 tons? It must be a huge house with no shade, vaulted ceilings and tons of windows? I would have someone competent make sure that the existing unit is performing to its full potential, and that there are no building envelope problems that you don't know about before I went and started replacing equipment.

Got a 2500sqft in central florida. East Facing house with a bunch of Windows on east and west...no shade, 10 foot ceilings in living area...8ft in bedrooms.

[SBKold]

The air handler is not being changed...the condesor is. The air handler will work with both 4 or 5 tons.

You CANNOT use 14seer condensor without a TXV. It will never work as good nor efficient as it will with proper valve.

Goodman has no data as to a piston size for their 14seer line (SSZ14).

If they insist on using no Valve...then you must use 13seer condensor.
(GSZ130601). Also Fan speed in airhandler will require to be set for 5 tons.

Trust me.

Id rather have the 13seer without TXV over a mismatched SSZ14 and piston.

[trentc]

You CANNOT use 14seer condensor without a TXV. It will never work as good nor efficient as it will with proper valve.

Goodman has no data as to a piston size for their 14seer line (SSZ14).

If they insist on using no Valve...then you must use 13seer condensor.
(GSZ130601). Also Fan speed in airhandler will require to be set for 5 tons.

Trust me.

Id rather have the 13seer without TXV over a mismatched SSZ14 and piston.

Okay, if they increase the fan speed do they need to increase the size of my return opening? Its 18" round flex right now

[udarrell]

The air handler is not being changed...the condenser is. The air handler will work with both 4 or 5 tons.

With a 5-Ton system I would want two extra large air return filter racks.

You want at least 1750-CFM of airflow through the indoor coil.

I would want a manual D performed on the duct system, air handler capacity, diffusers, grilles, etc.

I would think the condenser would have a Copeland Scroll compressor, which you don't usually need a start kit with a TXV.

Also, I wouldn't have a 5-Ton condenser without a TXV metering device on the indoor coil; I won't list all the reasons.