Room size 100 Sq. Ft. needs split unit AC be installed. Condenser unit cannot be installed on top of room, but far away on the roof top of the building, some 70 - 80 ft away.
One tech guy came to inspect location, said it would need a unit of 24,000 BTU ! Isn't that too much for such small room. He reasoned, if unit (condenser) was on top of room, no problem, be way smaller unit. Yet as it will have to be located far away, and for better cooling, especially when in hot desert-like climate, no less than 24K BTU, should be installed.
Any thoughts, input, folks with expertise in split unit AC.
Just to give you some perspective, the load calc below shows (very loosely) your 100 sq. ft room in Phoenix. One door, one window (South side), guessed at construction. Increased outside design temp from 107F to 125 F. Crappy loose construction. Still not at 1/2 ton needed. Obviously this is just an exercise and the actual variables are different. Gotta think 2 tons of cooling in that small room would be quite uncomfortable.
A hot climate and rooftop mounting do play an important role in capacity.
Having the condenser 75' above the evaporator also presents another challenge with liquid refrigeration. A solenoid valve may be required in the line.
Rather than specify a size I'd recommend you call and get a second price from a different contractor.
My gut feeling is the system should be closer to 18k.
Just installing a 18000 BTU mini split 2 head unit in my shop. 500sq ft in one side and 250 other side. Don't have 75 ft th travel to condenser but have lot of humidity in S GA. 24000 sounds like a lot even with AZ heat. (Lived in Phoenix for 10 years) Love dry heat. I am with Pete get another estimate.
You definitely won't need a 2 ton system, probably not even a 1 ton system. Best to find someone who knows what their doing. You will save on installation and operating costs with the correct size unit. I really can't believe the guy recommended a 2 ton system, that's so far off of what you need we thought your square footage was a typo.
Thanks, but that's what he said would be needed, to accommodate for the long distance (75 ft) cooling (refrigerant) hose / pipe travel - between indoor and outdoor units..
This is just an example, not saying it's the correct size (close though). I used this one because it has the copper line-set length data easily available. The installation of this particular unit (<15,000 BTUH) has a maximum allowable length of 82' with a 33' drop in elevation. There are less expensive units out there but I don't know the line-set length data on them. You may have problems finding someone competent to install anything you might buy on line. You will probably need a condensate pump too. While you consider this, are there other rooms that you would want to cool? Multi-zone units are available.
Does the guard keep the window/door open all the time? Good quality construction/insulation? Lot of factors to consider. Regardless, 2 tons of cooling is a massive amount for the room you describe.
Just to give you some perspective, the load calc below shows (very loosely) your 100 sq. ft room in Phoenix. One door, one window (South side), guessed at construction. Increased outside design temp from 107F to 125 F. Crappy loose construction. Still not at 1/2 ton needed. Obviously this is just an exercise and the actual variables are different. Gotta think 2 tons of cooling in that small room would be quite uncomfortable.
I'm in central AZ, currently the dry season. I've been running the ac around 9-10 hours a day. Feels plenty cold, and I'm not seeing any water damage on the ceiling where the air handler sits. My condensate drain pipe doesn't appear to be dripping any condensate from what i can tell, the ground is very dry and hard where the condensate would drip out. poured water through the drainage line through the access port by the air handler, and it's draining just fine, so signs of a clog in the piping.
So my question is, am I not getting any condensate because its primarily just hot and dry right now? or is it because there might be a problem within the air handler?
06-28-20, 09:57 AM
A/C split unit - what capacity
