Thank you so much for this very informative response!!!! I dont have any issues with my current system making too much noise, although I did locate the ac units far from the house. When I lived in a condo, I had issues with my neighbor's unit, which was very old, on our shared roof, and the noise drove me nuts. I'm now on an acre property, so that isnt an issue, but I really want to make this bedroom as quiet as possible.

I am happy to hear that the above ground duct return is the way to go. I will pass your advice along to the contractor. Do you think the air handler is okay in the master closet like it is? Do you think it will be loud? My air handlers in the current house are loud; however, they do not bother me as they are far enough away from the master bedrooms.

Thanks again!!!

You could install insulation in the walls of the air handler closet to minimize the noise. If you want it really quiet you use a material specifically to deaden sound. The door to the closet could have a solid core.

A variable speed 2-stage air handler would also be quieter. It would frequently on the low stage at night while you are trying to sleep.

If an attic is available it would be better for sound. Actually an air handler in a sleeping space might not be the best place for an air handler. There's just no good way to make them quiet. If not, mike_home's idea of the sound deadening blanket or sound blocking insulation in the walls would really help. By the way, this probably isn't an issue but if you are thinking gas heat, most codes will not allow a gas-fired appliance in a sleeping area. Just a thought.

I just replaced an AC unit in a master suite addition. The inside part of the unit was very poorly placed so the choice was to remove it and replace or to go with a ductless mini split system. I picked the mini split. There is a head unit on the wall in the bedroom and another one on the wall in the bathroom. Unless the fan is on high speed I cannot hear anything coming from these units. Oops! Take that back. The unit we got has a condensate pump integral to the system. The only way to service that pump and reservoir was to remove the head unit from the wall. We decided to install a separate condensate pump that sits below the head unit. That pump goes off every 30 minutes or so depending on the humidity being removed from the air.

In addition to the inside unit being very quiet, the outside unit is unbelievably quiet. The guts are outside. Then pipes go through the walls to the head unit where the cold stuff circulates through. The SEER is ridiculous at about 22. Here's a link to a picture of a unit close to what we got.

Thanks guys! We just dont know where else to put the handler. I DO NOT like it in the closet, but where do people put these things in additions? Definitely we will use as much sound deadening material and dry wall as possible.

Thanks dchall- I have seen those on hgtv, but I have never seen one here in AZ. I'll show it to the contractor to see if it's an option.

Here's a pic of the whole addition, if it helps.

Another issue you might want to consider is transmission of noise/vibration from the air handler to the rest of the house through the duct system. I had this problem with my first heat pump. When I had the next heat pump installed, they put in coated flex/canvas duct connectors at both ends of the air handler (that connect to the duct system.) That greatly reduced noise. I know there is a big debate about the value of these flex connectors, but I have found them beneficial.

Rockybird,

I would suggest a mini split also. You don't have to do a wall mounted air handler though. I personally like the cassette or the ducted mini splits. This is a link to the Fujitsu mini split for reference. Fujitsu, Mitsubishi and Daikin are well rated mini splits. They are incredibly quiet systems. These systems are very common in mid century mods because of the lack of attic space in many midcenturies.

Thank you guys! @homepro01 - I had an Ac co. Out here today looking at the units and they said since the addition is 4 rooms, a mini split wouldn't work. He said they are very quiet systems also.

Rockybird,

That is strange to hear. Did you give you an explanation? I am not sure that I have run into a situation where mini slits would not work so it would be helpful to understand where they would not work. They are very common in Eichkers through California which is similar to your style of house. They also predominate in the Carribbean and Asia for instance. I have a friend in Indonesia who built a huge house with nothing but ducted mini splits.

Good luck in your search!

Homepro01-Thanks! I will ask the contractor and report back what I learn.