Newbie here -- Hello! Looking for a window unit, AC only, 18000 BTU, 220v preferred...

The kicker is the cabinet size -- the opening height maximum is 16.5 inches. Most seem to be 18" or so.

No luck finding one that will fit. Anyone know of a "shorter" than usual unit...?

If I am barking up the wrong tree, please steer me in the right direction (other forum or site?) .... Thanks. Alex.

 

Have you considered a mini-split system? It would be more expensive but can be placed almost anywhere.

 

You may not need the full 18000 btu, may be able to get away with a smaller unit which will fit.

 

Dane - No, am only vaguely familiar with the split system... probably too pricey for my project. Where would you look for info on them?

User10 -- my area is 650 sq. feet, includes a full size kitchen... 18000 seems to be what I need once you've added some 4000 for the kitchen. Sound about right?

 

The sizing charts aren't very accurate, you can end up with up to twice as much capacity as you need.

There are online load calculators you can use to determine required capacity, here's one - HVAC Load Calculation - Maunualj - Whole House Loadcalc You can probably use it for a smaller space, not whole house.

Unless you intend on cooking all the time i wouldn't include heat from a stove.

I doubt that you need more than 12 000 btu/hr. In milder climates that space may cool fine with only 8000 btu, but it's a guess without a calculation.

 

User10 -- thx very much.... the calculator you mentioned says about 8700... quite a difference from 18000. I'll want to err on the high side (without overdoing it) to be sure there is enough cooling under extremes IE very hot day, guests over for dinner, kitchen in full use. Even so, maybe 12000 is enough?

 

FWIW, my house is 1,325 sq. ft. and I have an 18,000, so I don't think you need one that big. If it gets terribly hot you can always run a fan or two to push the air around more.

 

Shadeladie, that's very interesting... obviously I don't want to undersize but I hear that oversize won't run enough to dry out the air. Do you live in the South or somewhere that it gets beastly hot? I am in NE Michigan but it still gets hot at times. I am thinking 14000 now, sort of a compromise and hopefully not too large.

 

No, I live in Phila., PA. It can get pretty hot at times but the 18,000 cools just fine. When I cook I just point a fan towards the kitchen and it cools it off.

 

Yes, I have stand fans and ceiling fans to aid the air flow a bit, seems to allow a slightly warmer setting (current units in bedrooms only). I will definitely get a quiet model since the main room is a home theater/audio room.

 

In michigan 12k will be plenty even with high ceilings and a lot of windows.

For guests, figure 340 btu per person if at rest, up to double that if more active/moving around.

If you have a high enough budget and your window is large enough, you can get a 14k inverter window unit - the compressor is variable capacity and it ramps down when the load isn't high, so the penalty for oversizing isn't too bad.

https://www.homedepot.com/p/LG-Elect...IVSM/303947186

 

Very helpful, I can see that the original guesstimate of 18000 was out of line (was based on some store's chart). Did not know about the inverter type, will definitely consider that. Seems that 12000-14000 would be a good 'more is better' range, as part of the area is "open" to the back end of the house via a short stairway (split level)... rear area includes a full bath and a laundry room, though the laundry will probably be kept closed during heat waves. Individual small AC units in two bedrooms. Ideally these rooms would be left open to help the new AC to cool the entire home.

 

A certain periodical I will not mention by name that specializes in product evaluations tested window air conditioners in its July 2018 print issue. They only went as big as 12,000 BTUs but the winner in that category was the (115Vac) LG LW1216ER, scoring 82 points out of 100 and besting second place by a margin of six points. I just checked the LG website and they claim that that model is 15" tall.

Said article gave it a 'good' rating for noise on low power but only a middling rating on high power. I have a 6000 BTU LG in my home office that runs 24/7 about 10 months of the year on account of heat from all the computers and whatnot. After five years of trouble-free service it still runs like it will live forever. However, whenever the compressor kicks on, regardless of the fan setting, it makes racket like a tractor-trailer downshifting gears.

 

Thank you, Fred, and everyone for your input and suggestions. I have experienced under-sized unit when trying to cool a small home, and don't want to make the same mistake (it was in FL though, and the unit ran on full blast all day trying to cool a small home). So, 14000 is my goal and I know I can find them in the height I need to fit a particular window. Very important is running noise, it must be quiet as not to muck with the home theater sound.

 

A lot of systems that perform poorly are not actually undersized, but have problems including but not limited to insufficient airflow, improper charge, leaky ducts, mismatched components.

When you buy a window unit, provided it's not defective it delivers rated capacity out of the box so you shouldn't oversize.

You just need to circulate the air from the unit using fans so the supply air gets distributed properly and not just pulled back into the return, causing short cycling.

 

Thx... am hoping to avoid a problem unit by using CU guidelines and others... but again, because of the high ceiling in the main rooms and the open connection to the rear portion of the home, I'd like too err on the side of good capacity and not have to strain an underrated unit. And yes, have always intended to supplement the cooling with ceiling and stand fans. Wishing I could afford central, but this floor plan doesn't lend itself to that anyway. Thanks again.

 

a mini-split is the best long per option but is expensive.

12k window unit will have plenty capacity to spare, i'm a little north of you in ontario canada and it's not uncommon for 12k to be able to condition 800 to 1200 sq ft. so 14k if it's non inverter is too much in a slightly warmer climate.

if this was my project i would size it close and get 8000-9000 btu - but i care about dehumidification more than making it cold and wouldn't mind the temp going up to 78 inside a couple of times each summer.

 

a mini split is more expensive, but if you install it yourself (correctly), it will save $ in your bill and eventually it'll pay off the difference. meantime, you would enjoy the much more silent operation.