[django11]

I'm slowly in the process of installing a fixed ac unit.  Something like this:


Presently I am just using a big old window unit. 12000 btu if memory serves.  They are quite cheap and don't cost much to maintain ( actually I have never spent a cent on one) but it is pretty heavy and noisy and I certainly foresee a time when I won't be able to muscle it into place (it is in a window at the top of a staircase ).  I think I know the pros of the pictured units.  What are the cons?

[thunderbrick]

I have nearly 9 years experience with a Mitsubishi "Mr. Slim" on a special project home, and was responsible for maintaining  it.  I remember one service call, one clogged drain pipe, and having to clean mildew out of it after about 7 years.  If I had the cash I'd buy one right now for my home, but I have bigger AC issues right now.

Quiet, effective, dependable.  And easy to work on.

[django11]

I've been doing a little research.  Expensive install...

[TomS]

I've been doing a little research.  Expensive install...

I've been looking at these mini split type units for my daughter's 1 story bungalow style home in Atlanta. She also has window units which are a real pain and they've actually had a couple stolen out of the windows for scrap 

They have an old gas forced air central heating system coming from a basement with huge duct work, so I thought these might be a reasonable option for whole house A/C instead of reworking all that and/or adding a bunch more small ducts. The problem is that you need quite a few units and/or zones to cover it and they seem to be at least 5-10x more expensive per unit than the old window units. They have a LR, DR, 3 BR's, and kitchen to cover, all small separate rooms on one floor. I hadn't even checked installation costs, but from the DIY video I viewed, if you already have outlets placed (unless you need 220v) and exterior wall space is available it really shouldn't be too bad.

I too am curious to hear others' experiences with them. The only other major drawback I can see is it takes up wall space and really sticks out amid the normal decor in each room. Maybe for an addition or something it wouldn't be such a big deal.

Tom

[django11]

I googled diy on the units and the ones I have seen aren't diy friendly.  I can do the electrical and I can hang the units but you need specialized equipment for the coolant.  The HVAC companies don't seem to come cheap from what I have read.

We presently do pretty well with one 12000 Btu unit for a smallish two story house near Montreal.  So I am thinking  one 18000 btu will do.  I'll probably really improve my insulation first.

[TomS]

I googled diy on the units and the ones I have seen aren't diy friendly.  I can do the electrical and I can hang the units but you need specialized equipment for the coolant.  The HVAC companies don't seem to come cheap from what I have read.

We presently do pretty well with one 12000 Btu unit for a smallish two story house near Montreal.  So I am thinking  one 18000 btu will do.  I'll probably really improve my insulation first.

I spied a video somewhere that showed exactly how to do it. Made it look really easy in fact. I'll see if I can find that one somewhere for you.

[TomS]

Here you go http://www.youtube.com/watch?v=PdMRVO_NOz4

[django11]

That particular model (AUX)seems fairly simple.  This one is more involved http://www.youtube.com/watch?v=xUJMzKPwjbI

[john1970]

I have a traditional New England home with baseboard heating and no duct work.  I just finished having a Mitshubishi Mr. Slim heat pump system installed in every room in the house.  Overall I am quite happy with the system: 

Advantages:
1) Very quite indoors compared to a window or thru wall unit
2) Outside compressor is relatively quite at only 50 dB (much quieter than my neighbors central AC unit)
3) More efficient that a window or thru wall unit due to inverter based compreser
4) Much less expensive to install if your house does not have ductwork
5) Provides AC in the summer and a secondary (or backup) heat source in the winter.  Althought the heating system becomes less efficient below 32 F it can provide heat down to 0 F. 

Disadvantage:
1) Wall mount units do not blend in as well as a central AC vents.  Although the indoor units are smaller than the through the wall units.  Mounting the unit toward the top of the ceiling and in a corner can help make them less intrusive in a room.


Good luck,

John

[django11]

Well I had a unit installed and it has been working for a couple of months so I thought I would post impressions.

I have a smallish house at about 1500 feet to cool sans the basement and the second floor is hardly insulated (upcoming project).  I got an 18000 btu unit and installed it on the second floor near the stairs.  The unit was professionally installed and comes with a 10 year warranty on parts and labor.  At first the second floor would be nice and cool but we would still be roasting down stairs so I purchased a through wall fan and installed it in the floor between the first and second floor.  Problem solved although the fan is a bit noisy. There is still a bit of a difference temperature between the first and second floor but not any issue.  For example on Friday it was  93  (about as hot as it gets around here) and the second floor was at 68 and the ground floor was at 73.  That is with the system maxed out mind you.  The installer told me that what wears out the unit is the compressor turning on and off.  He says there is no problem with it working all out so I don't worry about it. And once  I reinsulate this fall things will become even better. 

The unit as four speed settings including "quiet" for sleeping.  It is totally quite in that mode.  The installer does not recommend the units that heat as he says there is a part that breaks often requiring expensive repairs.  In any event having a heating unit on the second floor near the ceiling would be pretty close to useless.

The brand name of my unit is Friedrich.  Apparently it is identical to Fujitsu.  Very quiet.

Central air would be better but just the same I am very happy and  .