Heating, Air Conditioning, Fridge, HVAC/HVAC system

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I just had a new unit installed 2.5 ton for approx 1000 sq ft mobile home. Main air ducts(in and out)replaced (Note: under home the ducts connecting unit to ducts in the structure of home itself). New unit is a Goodman 13 seer. Air cools however the air in the home feels stuffy and air flow is not as strong as with old unit which was about 12 years old. Contractor came back out and is suggesting a second return be added but original return at 16x20 was working fine with old unit and when checked is pullling air well. Contractor maintains there are no kinks in the ducts replaced. Can't figure out what is problem.

Answer
Elsie,
I'm not sure what exactly your system is? ducts and unit,
Is it a split system Or a self contained system?
Is it heating and cooling or cooling only?
For 2.5 tons of cooling the blower needs to produce 1,000 CFM of air, The supply air ducts and the return air ducts need to be of sufficent size  to allow enough air to flow through.
Most all units have vereable speed blower motors that will run faster or slower depending on how they are wired/connected.
You need at least 200 square inches of free area for the return air to pass through, I don't know what exactly the  "original return at 16x20" consists of?
16X20 is 320 square inches, if there is grill over that area it reduces the free area 50% which would be 160 square inches,
If it's a filter grill with a filter it can reduce the 160 another 50% which would be 80 square inches, less then half what you need.
There is a good possability that the cooling coil minght ice up and freez over if enough air dosen't pass through.
I'm limited in knowing exactly how your system is put togeather?

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Jim Barnhart

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Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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