You do NOT want too large of an air conditioner.

AC does two things:

1. Removes heat

2. Removes humidity

This second is the most important. If you put a large AC unit on a small house, then your unit will only run very rarely. The problem with that is that this allows humidity to develop, and that leads to MOLD.

A smaller unit that runs all the time is a better idea. You can figure on 15 years from your inside and outside unit, maybe a little less if you are in Florida, where it is going to run year-round and is subject to frequent lightning strikes.

Good luck!

N!

I think 2 ton is about right for my insulated 900 sq ft garage, although the two A/C companies I've had come out to give a quote were leaning toward 2.5 ton.

I like that the Klimaire corporate headquarters are in Miami, Fl. They sound like a young company that strives to build a good product at a good price.

For the $2,800 Mitsubishi system I could just about get a central A/C system but that's really beyond my budget for the garage.

Check and retorque all the connections on the terminal blocks. I've seen a few of them melt and burn up from poor factory connections. Other than that, I haven't seen any problems with them.

The AC in our automobiles is a split system. As a matter of fact the central air system in our homes is a split system. The evaporator and condensor are separated! With central air you are simply ducting the cool air through the house. A split/ductless system you are cooling the one room or area with the evaporator in the room. Coolant flow from condensor to evaporator is same. Air movement within the area is another matter. A felony fan or oscillating fan helps.


I wouldn't hesitate to install a split/ductless system over a window unit.

what color is the roof

anything other then white is hot

we just painted a gray shingle roof white
and the house is a lot cooler
105 in the sun 95 air temps will get 120-130 on a gray roof

yes you will still need better A/C but not as many btu's = $$

We have a ductless split heatpump for about 5 years now, works great.

If I understand correctly you just want to cool the attic... if so the ductless system is the way to go.

But seeing as this thread is several years old you probably have already resolved the problem. :D

Many factors in switching a old heat only system to A/C... long story short cold air needs larger ducts.

Also if I had the luxury of starting from scratch I would go with a package HAVC only because you don't have to worry about leaks at the connections.

I just a quote back on a central AC system and it's $3,375 which is more than I want to spend. One other issue now is that the contractor already contacted the city about pulling a permit :o

Of course I was planning to pull a permit even if I did it myself, but now I REALLY have too :mad:

I think I'll go with a ductless mini-split if I can find a cheap enough electrician to pull the permit.

David,

There are 2 ton package units, already filled with freon, for about $1300. All you have to do is cut 2 holes in the wall, run a duct/diffuser in the ceiling, and a return line to the outside unit. They are not the most efficient units (13 SEER) but you're not going to keep it on all the time.

13 SEER is more than good enough. The vast majority of A/C units today are likely less than 13 SEER. Based on my ammeter, you'd pull less than 10 amps (likely under 8 amps) of current to run a 2 ton unit. 2.2 kw per hour. $0.12/kwh, so 25 cents per hour at most.

Best bet is to keep your upfront costs reasonable, and do a quality install. Ductless would be a great way to go, but a package unit may be cost competitive.

My other thinking on the ductless is how long we live here. If we move, I could take the mini-split to the new garage with minimal effort.

I was able to finally get ahold of the guy who installed our house AC for a song. Hopefully that quote will be within the ballpark for a garage system.

David, on a mini-split, someone will also have to evacuate/charge the system for you, since the evaporator is installed separate from the condenser. On a package unit, you are only running ducting and electrical.

I bought the 2 ton Mitsubishi Mr Slim ductless mini split system. After looking at all the specs I decided the Mitsubishi's better efficiency and quieter evaporator was worth the extra money. With the slow pace I get projects completed it'll probably be a week or so before I can give a product review.

I did look at the package systems like the Bard units we have on our traveling crew shacks but they didn't seem that much quieter than a window unit. Their efficiency isn't very good either.

Are you planning on running it all the time, or just when you want to work? And how big is the garage?

My installer told me Mitsubishi were the best.

My parents just did the ductless split system in their 1919 farmhome and it works GREAT. And yes, you see them everywhere in asia and on the islands

I plan to run it all the time. It's 19 SEER. I'll turn it up during the day and down when I'm hanging out in the garage which has been almost every night and weekends. The garage is about 900 sf and it is insulated.

who wants my Mitsubishi Mr Slim ductless mini split system?

Obviously I have my own system now but what are selling and why?

it is undersized for the room and not really needed after I got my shade trees growed up & put in new windows

shipping to Houston would be a bit high