# Interest group forums > Energy and Resource Conservation Forum >  Air-conditioning ?

## Electrode

Logik 10 000btu Portable Air Conditioner



Good day, I would like to ask some help regarding Air conditioning systems. I would like to purchase one next week but know they are heavy on power. Unfortunately I don't know what the power consumption is but after doing a search it is safe to say that it consume about 1000 Watts per 1 hour of use. Well that is what most models consume, I will have a look at it within next week. My bedroom is about 5x4=20 square meters.

The model I am considering is ideal for a room size up to 18 square meters. I don't think that 2 square meters more will be a problem. My question is how long does it normally take to cool a room down? I have no experience with these systems and would like to know if I can use it at night when I am trying to sleep in this unbelievable heat.    

If anyone can give me information on how long it would take to cool a closed room, I would greatly appreciate it.

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## Justloadit

The question is a double edge.
1. How hot is the room when you start the aircon.
2. What other heat sources are there in the room generating heat. Electrical lighting, electrical equipment, electronic apparatus, direct sunlight on walls and through windows.
3. What temperature is 'cool'?
4. What materials are in the room made from, as they could be absorbing the cool air, and not passing it on to the room. Typical is mortar
5. What is the relative humidity, as this affects the efficiency of the aircon
6. What is the ambient temperature of the outside evaporator, as this affects the efficiency ability of the aircon

Human bodies generate approximately 300w of heat per hour, so must be taken into consideration

Check this out Tips on choosing an Aircon
Top Ten things about aircons

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## Electrode

It is hard to imagine that most people would have that type of information. The equipment alone to take every single measurement will be expensive. I don't think that your average customer would even bother taking those measurements. This is what I do know, The outside sun does hit the window directly from about 12:00 PM to about 5:00 PM. The room is fairly airtight if all windows are shut and the door is closed. Obviously the room isn't completely airtight due to air ducks on the side of one wall and the one above the door. Covering them up might be a bad idea, as fresh air need to come in from somewhere. 	     

Using a BTU calculator I calculated that I may need about 21,678 BTU/hour or 6,353 watt.




> Reference
> 
> The British Thermal Unit, or BTU, is an energy unit. It is approximately the energy needed to heat one pound of water for 1 Fahrenheit. 1 BTU = 1,055 joules. 1BTU/hour = 0.293 watt.
> 
> BTU Calculator


Since I will be using it at night the sun will not be a contributing factor. It is of note that the system i am looking at is only 10000 BTU and if the calculation is correct and I am reading it correctly it will be able to cool the room down in about 1 hour or so. I don't know I am not an expert but this is the info i got.

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## Houses4Rent

I have no idea about aircons, but the picture you posted is not a split unit I believe i.e. oen part is outside and the other inside and its not mobile either. Is it not only a evaporative cooler and not an air con? I might be wrong.

Why not ask an installer for aircons for input/free quote?

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Electrode (28-Dec-15)

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## Brett Nortje

> Logik 10 000btu Portable Air Conditioner
> 
> 
> 
> Good day, I would like to ask some help regarding Air conditioning systems. I would like to purchase one next week but know they are heavy on power. Unfortunately I don't know what the power consumption is but after doing a search it is safe to say that it consume about 1000 Watts per 1 hour of use. Well that is what most models consume, I will have a look at it within next week. My bedroom is about 5x4=20 square meters.
> 
> The model I am considering is ideal for a room size up to 18 square meters. I don't think that 2 square meters more will be a problem. My question is how long does it normally take to cool a room down? I have no experience with these systems and would like to know if I can use it at night when I am trying to sleep in this unbelievable heat.    
> 
> If anyone can give me information on how long it would take to cool a closed room, I would greatly appreciate it.


Oh you again? hey man!

Your problem of sleeping will nearly instantly be answered with blissful sleep. if you were to observe that hot air rises, then you will also notice that you sleep near the bottom of the room. then, you need to know that the cold air is pumped out quickly and atomically, as, it will send a lot of 'cold air' into the room like a ripple on a pond. these 'waves' you will notice are not 'solid' as they have holes in them, and, they will quickly spread like ants, yes?

Then, they will quickly bring the whole room temperature down, as, hot and and cold air 'mix.' this is because opposites attract, and, they will quickly dilute the cold air into hot air, like a hair spray bottle, of course.

I reckon, in a two square meter room, they will be all over the place 'instantly.' then, as the pressure grows, it will cool at a rate of, with the motor or cooling device cooling at a rate equal to itself, well, as big as the cooling vent is in 'length and breadth' times by as much of a rate as it is coming out, you will have your answer.

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## AndyD

If it's a bedroom and you're using the aircon at night then heat load from window area and direct sun etc isn't going to be an issue and a 10000 btu unit would suffice for a 20 square meter room.  

I'm also not sure what that thing is in your picture, it might be an evaporative cooler rather than an air conditioner by the looks of it.

**edit** It is an air conditioner of some sort according to the spec. It must have a flexible hose or duct that comes out of the back and you'd need to route outside I think.

At 10000BTU and assuming it's not inverter driven etc I'd expect your power consumption to be 800-900 watts. On the conservative side this means you'll be consuming 1 unit of electricity for each hour it's running. It the room temperature drops to the point where the air con is cycling on and off on its thermostat then maybe you'll be using about half a unit per hour.

How much is your electric unit price Electrode? If you electricity is on a sliding scale then use the highest unit price you pay.

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## Electrode

Hi everybody, I got a Delonghi Pinguino.



It is a powerful system running at a maximum cooling capacity of 12500 BTU/h at 3.67kW

I do not use the maximum setting on it and it consumes 800Watts of power exactly. It takes about 2 hours to cool the room down with us in it. and turns on once every few hours at night. I do not use it in the day at all. It did come with a plastic pipe that hangs out of a window but it is no bother at all. 

I am very happy with it and will recommend it to anyone looking for a good air-conditioning system. It is also a heat-pump unit with a maximum heating capacity of 11250 BTU/h at 3.30kW but I don't think it will get used much for heating.

Total cost was R7000 inc VAT

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