In May we had a Nordyne IQ Drive system installed with all new duct work and 2 return vents. The air handler sits in the middle of our home which our living area is centered around. See attached pictures for location of air handler & vents.
Problem #1: When the system ramps up to higher blower speeds it sounds like we are in a wind tunnel, when ramping down there is a high pitched whining noise, low speeds sound tolerable.
Problem # 2: There is no ramping up, when the air handler is off and comes back on, it is at high fan speeds, and there is no ramping up.
Problem #3: In the Florida summer, humidity averages 60%.
I have contacted the installation company and they have tried to remedy these issues to no avail. Finally, they have admitted this is not right and have agreed to replace the system with another brand.
Question #1. Do all variable speed air handlers tend to be loud at the higher blower speeds?
Question # 2. We have a 4 ton system, the company insists this is the correct size and a 3 ton would not cool enough. Our home is only 1752 sq. They said they have done the calculations and it came out we needed 3 ½ tons, so they upped it to 4. Is that oversized? Would a 3 ton cool enough and have better humidity control?
Question # 3. Any suggestions on what brand AC system that has a quiet air handler?
Thank you for any help with this.