[HELP] Electricity Consumption of 5,000 btu vs 10,000 btu window type AC

[erjohntalag]

Good day fellas. I'm having a trouble in chosing which air conditioner I will put in my bedroom. My bedroom is 150 sqft and not properly insulated. I live in a very hot environment, the philippines, with the average of 35C temp outside our house from 9am to 5pm. Actually, I already have a 5,000 btu in my bedroom and it was said to be effective for up to 150sqft room which is the same size as mine but unfortunately my AC takes a lot of time to reduce the temp from 35 to 30. It takes about 6 to 8 hours to do so and when it reaches that temp it would be night already and it just loses the point of cooling my room since it's not so hot already. Also, my AC can't reduce the temp below 30C. Fortunately I have an extra AC from the guest room which is 10,000 btu, my problem is I think that my electricity bill would jump really high if I switch from my smaller AC to the bigger one. And here are the scenarios that makes me reconsider. First of all my smaller AC is running continously from morning 'til evening, I mean continously since I never really notice it resting it's compressor so I was thinking it would be different if I installed the bigger AC. Also, I think that the rate of cooling would be faster with the bigger AC and it would reach my desired temp during the hot hours.

In a shorter version, will my 10k btu aircon consume siginificantly higher energy compared to my 5k btu aircon which runs continously? Thank you

I hope you guys can find time and reply to my post. Thank you.

[The Viking]

In short,

Yes, an 10,000 BTU unit will consume considerable more electricity than a 5,000 BTU unit.

However, does that really matter?
If your 5,000 BTU unit doesn't manage to bring the room temperature down then any money you spend on running it is completely wasted. Wouldn't you rather get something for the money?

[nike123]

Your air conditioner does not consume energy. Your room is consuming energy. Air conditioner only transfer energy more or less efficiently.

I suppose that your 5000 btu unit is mobile one! With these, you have another issue, which is that they consume your already cooled room air to cool their condenser. That is inefficient and waste of energy.

[install monkey]

on the plus side your 10000btu unit would get the room to setpoint so it wouldnt run continuously so your leccy bill wouldnt be double what it is now

[erjohntalag]

Thank you guys for giving a thought about my setup I'm really glad that you took your time and energy in reading and responding. Anyway, I will really consider installing my 10,000 btu in the room and see if my electricity would double the next month, hope not. Also, my 5000 btu is not a portable one, i guess, it's just a small window AC mounted at my wall. So my next problem would be making the AC hole bigger in my wall since my window ACs are not installed in my window but rather in the wall. Thank you again.

[The MG Pony]

If long term money is an issue invest in a ductles mini split that is well sized, all so keep in mind humidity is the largest consumption of a units cooling rating, if humid bulk of the btu rating will go in removing this water.

So to size, we need to know humidity+heat gain

If very humid and lots of out side air is comming in you may need up to a 13Kbtu/h unit.

But for now try the 10K unit, you will at least then get your monies worth out of the energy consumed in comfort!

[erjohntalag]

Yes I read that humidity is also a big factor as to the air conditioner requires to reduce the level of humidity before it actually cools, correct me if i'm mistaken For my room's situation, I think it's also a big factor because as I have recorded, my room averages from 70% humidity all throughout the day. But even if my RH reaches 40%, my 5,000 btu still takes a lot of time to cool a degree I don't know if it's a brand issue (Haier) or is the cooling capacity of the AC is just insufficient for my room.

I can't update yet about my 10k btu AC since I have not made the hole in my wall bigger so I think it will wait for a while until I get someone to do it for me.

Another question. Is there a standard rate of temperature drop per hour using a proper sized AC?

[The MG Pony]

No, as T drop is a function of heat load and humidity, basicaly your 5K is using all its cooling power condensing the water out of the air leaving very little left to cool the room, and if humidity is staying constent you have an air leak some where.

The ten K will be hard pressed even unles the room is well sealed.

[nike123]

If you using your unit on low air flow setting, than it is more latent heat (water condensation) that unit is removing than sensible heat (air cooling). Actually, unit than works in more like dehumidifying mode. For maximum sensible heat removal, you need higher air flow.

As these units are more noisier than split-systems, we (users) are usually run them on slow fan mode.

[The MG Pony]

Oh I know all to well Nike I got a 13.5Kbtuh unit, badly placed unit as living room is cool but bed room cooking (It is an rv) noisy but makes it berable.

[MikeHolm]

Good idea to have an RV in Redvers so you can get the hell out of dodge when the going gets tough, haha.

ERJOHN, it might be a good idea to see if you can get a cheap ductless split which might be better than the through the wall unit.

[The MG Pony]

Oh long out of redvers, the job was hugely unstable so not worth stay atm I am between regina and saskatoon, exactly where not to be but stuck atm as I can not find any where to stay in either place and a 3h commute is a tad much!

[nike123]

Through the wall unit have one, to me, crucial benefit against ductless split unit. And that is, fresh air supply!
I prefer that in contrast to less noise.