Aircon Sizing - Your Thoughts as a User?

[AlwaysRt]

Many of you have Aircon purchasing/installation experience, mine is irrelevant as all from a 'central air' country.

What would you suggest? I have just moved into a house with no Aircon. It is a long-term rental and the owner will allow only one split unit and no window units. The master bedroom is 15 m2, the best location I see is an exterior wall blowing directly at the door from the sala. The sala is 30 m2. I would like to cool the sala in the evenings and bedroom only at night.

Will installing a 2hp unit, sized for 45 m2 bedroom + sala work or is the doorway too much of a restriction? Would it be better to install a 1hp unit, which is still oversize for the bedroom only, and accept limited cooling but still should see a significant drop in humidity so a fan in the sala is fine? Any other ideas keeping in mind the 1 unit only requirement?

Thanks, Steve

*EDIT* for crying out loud, I wish my brain still worked!!! Anyway, to clarify my confusion above. 1 unit allowed only (split, compressor outside, air handler inside) to be installed on bedroom exterior wall (sala installation in front of the house or the other side blocking the kitchen entry not allowed either). That will have the air being blown (if straight) to the bedroom door leading out to the sala. I will close the door at night as no need to cool the sala when sleeping.

Edited May 15, 2017 by AlwaysRt

[Jack Peterson]

For me the 2 hp as it will do the Job you want without too much energy used the 1 hp would be fine for just the Bedroom but will overwork to do both, Now Steve, to install a Split unit you will need the Inverter on an outside wall so can you see that OK, you don't really need it to point it at the bedroom just leave the Door open and the Air will circulate around and do the Job If you don't want to cool the bedroom too early just close the Door. and turn the temp to a comfortable setting for the sala then say 1 hour before sleep time open the Door and it will cool it.

This is how we Cool the maids room as there is no A/C in there.

Hope it helps.

[Bruce]

Too many unanswered questions such as roof color, number of windows, exterior wall colors, will the bedroom door be closed at night? So ignoring that, as you are limited to (1) unit you need to clarify with the owner if he means 1 outside unit and 1 inside unit or, 1 outside unit and 2 inside units. (They make them up to 8 inside units on 1 compressor unit.)

If it is 1 and 1, where will you spend the majority of your time? Which room. How cold do you want it at night? Buy the larger unit and install in the larger room and use a floor fan to blow into the bedroom if you are not getting enough cooling at night and assuming the door will be open. If not, then buy the same larger unit and install in the bedroom and use the floor fan during the day for moving air out into the larger room. Bedroom door is the deciding factor open or closed at night.

Do not worry so much about over cooling the bedroom with the larger unit as most houses there have no insulation and a high heat load. No matter what size you buy, when the thermostat gets cool it shuts the unit off. If you buy a higher end model, you can use the dehumidification mode to control the unit rather than the standard thermostat temp control.

If he allows 1 outside unit and then 2 inside units, with a 24,000 outside unit, buy an 18,000 for the larger room and a 9,000 for the bed room. This will keep you cool. As you will be leaving the AC when you move out, I do not see what issue the owner may have.       

 

Edited May 15, 2017 by Bruce

[Gratefuled]

They sell portable air conditioners. Just about any size that you want. 

Check out the LG models.

[Bruce]

23 minutes ago, Gratefuled said:

They sell portable air conditioners. Just about any size that you want. 

Check out the LG models.

Portables are a poor choice. High energy consumption as they blow cool air out one end and HOT air out the other end. For those with a hose hook up to put out a window.... that air being blown out, COMES from the same room you are trying to cool. For every cubic foot of air blown out the window, 1 cubic foot of hot, humid outside air must be brought back into the room. Portable AC units are made for tents and outside weddings and very temporary use. 300 cu. ft. per minute out, means 300 cu. ft. of hot air must come back into the room.

[AlwaysRt]

36 minutes ago, Jack Peterson said:

For me the 2 hp as it will do the Job you want without too much energy used the 1 hp would be fine for just the Bedroom but will overwork to do both...

Hope it helps.

 

31 minutes ago, Bruce said:

Too many unanswered questions such as roof color, number of windows, exterior wall colors, will the bedroom door be closed at night? ...    

 

after re-reading my OP it needed an edit, here it is. "for crying out loud, I wish my brain still worked!!! Anyway, to clarify my confusion above. 1 unit allowed only (split, compressor outside, air handler inside) to be installed on bedroom exterior wall (sala installation in front of the house or the other side blocking the kitchen entry not allowed either). That will have the air being blown (if straight) to the bedroom door leading out to the sala. I will close the door at night as no need to cool the sala when sleeping."

Roof is read, bedroom has (2) 200mm x 120mm windows, sala has (1) 200mm x 120mm and (2) 70mm x 120mm windows (all dual pane insulated sliding), sala entry double solid wood doors, exterior is western US burnt orange.

21 minutes ago, Gratefuled said:

They sell portable air conditioners. Just about any size that you want. 

Check out the LG models.

Air conditioners? I have seen the portable air coolers - based on same principle as western US 'swamp coolers' which are not very effective in a humid environment.

[intrepid]

Go for the larger size.  Have two fans available when cooling the Sala.  One just inside the bedroom door to push the cooler air into the Sala and a second one oscillating somewhere in the Sala to keep the air moving and feel cooler.

[sonjack2847]

I used to fit heating and it was the norm to slightly oversize, as you can turn it down but it is overworking the unit,  if it has to work all the time with a smaller one.

[Jollygoodfellow]

2 hours ago, AlwaysRt said:

Air conditioners? I have seen the portable air coolers - based on same principle as western US 'swamp coolers' which are not very effective in a humid environment.

 In Australia I had a refrigerated one with compressor, not water cooled. Only good for a small room.

[robert k]

If you are leaving it when you move, I'd be looking for a new landlord. Two AHU inside shouldn't be a problem.