Written Its not a scam. Actually very technical reasons are behind this.In an air conditioner the coolant is circulated through two sets of coils- Evaporator and Condenser. The evaporator is present in the indoor unit and is responsible for the actual cooling effect of the air conditioner. When the warm and moist indoor air comes in contact with the evaporator, heat exchange takes place between air and the coolant. The coolant being at a much lower temperature, absorbs the heat from the air in contact and cools it down. So if the contact between the air and the evaporator is better, greater cooling will be achieved. This is taken care of by increasing the surface area of the evaporator. If the coil has a bigger surface area, more air will be in contact with it at a time. Split ACs sport a bigger evaporator in comparison with window ACs which helps in achieving more cooling per unit power consumed.The similar story follows in case of the condenser. The condenser is present in the outdoor unit and is responsible for cooling down the coolant itself.

After being compressed, the temperature of the coolant rises and it has to be lowered for proper operation. This is done by the condenser. The lower the temperature of coolant, the better the cooling. As in case of the evaporator, if the surface area of the condenser coil is increased, the heat exchange will take place in a better way. Split ACs generally consist of a much larger condenser which helps in cooling the coolant more effectively. Due to the above two factors, the compressor of a split ac is at a lower load and draws lesser current. Another important factor is air distribution. Split ACs are able to distribute air more effectively than window ACs. This helps them cool faster and thus the compressor shuts down quicker.All these factors make a split AC more efficient than a window AC.Written Written Written Window units only need to achieve between 9.4  and 10.7 depends on size. But an central AC unit must have a minimum energy efficiency ratio of 12. One reason behind window AC has lower rating is that, it is impossible to fit much advance hardware into that little box.

While Central air conditioning can work  at a range of speed and condensers in most window units only have two on and off. Which can make a significant difference in energy use. Central air units are getting more smarter according to more efficient and beneficial . Programmable thermostats of central air conditioning can make up for forgetful central AC users by shutting the unit off when no one is at home.copper in ac unitssmallest window unit you can findhow to wire a ac unit The remote may be a cool thing, but to be honest, never used it.central air conditioner size square feet I have a cabin with very small windows and needed something that would fit. On the hottest days, I had 3 of these units running to remove the humidity and cool down about 1200 sqft of space.

It never got real cool, but it manage to keep the place at a level the was much better than 80% humidity and 90F like outside for the one week a year we get that. These work much better than those portable air handler with hoses. I probably could use two more of these to get the house down a bit cooler. In a 11x13 bedroom, it managed to keep it around 76F, with lower humidity. Walls are 4" and insulated, ceiling has about 12" of insulation. It does not push a lot of air, even at high speed. If I compare it to my old unit from 15 years ago, it may be more efficient, however that old thing was probably 50% stronger than these. I could cool the whole place down with just two of the old units. Even though I had these tipped down in the correct direction, water still built up inside. I'll have to look at drilling a hole in the back, since it looks like it has to get over a lip. Found that out the hard way when I lifted them out of the sill. very efficient and quiet for the bedroom

I had been considering returning it for a more powerful unit but as I used it I decided that it actually did a really good job and I also noticed that my electric bill was actually reduced with no other reason other than using this unit in my bedroom and had it on constantly. also quiet and that adds up to who could ask for more? Great cooling at a great price I have this in a small bedroom, so the cooling challenge is not great. That means I can cool the room rapidly and then maybe just turn it off for a night of sleeping. The unit is in a window near the corner of the room but the air vents adjust the cool air out to the center of the room so the cooling is pretty even in the room. When i say it's quiet I mean that it is certainly no noisier than the unit it replaced, but these room-size air conditioners are inherently sort of noisy. Having the remote control is really great--the unit it replaced did not have that. I will never have an a/c without a remote again. I live in sw Florida - its hot!!

My central ac went down so ordered this window unit. It works very well. It can actually do 2 small rooms comfortably. I love the remote. If I wake up in the middle of the night and need it either lowered or raised, its right next to me on the nightstand. Well worth the money. I took a chance on a brand that I had never heard of, and I'm happy I did. I would buy another. We've had mid and upper 90's . Cools a small office building that i have seperate from my house and seems to cool as well as the previous 10000 btu I had in it. It is on 24 hours a day and in energy save mode , so it cycles on and off.Each air conditioner has an energy efficiency rating that lists how many BTU's per hour are used for each watt of power it draws. For room air conditioners , this rating is the Energy Efficiency Ratio, or EER. For central air conditioners, this rating is the Seasonal Energy Efficiency Ratio, or SEER. These ratings are posted on an Energy Guide Label, which must be attached in a visible place on all new air conditioners.

Many AC manufacturers are voluntary participants in the Energy Star labeling program. Energy Star labeled appliances indicate that high EER and SEER ratings. The air conditioner EER is its British thermal units (BTU) rating over its wattage. For example, if a 10,000-BTU air conditioner consumes 1,200 watts, its rating is 8.3 (10,000 BTU/1,200 watts). The higher the rating is, the more efficient the air conditioning unit is. However, a higher rating is usually accompanied by a higher price. Let's say that you are given a choice between two 10,000 BTU air conditioning units. To calculate what the payback period is on the more expensive unit, you need to know: Let's also say that you plan to use a room AC in the summer (approximately five months a year, depending on where you live) and it will be operating around eight hours a day. Say that the cost of a kilowatt-hour in your area is approximately $0.10. The difference in energy consumption between the two units is 200 watts, which means that every five hours, the less expensive unit will consume 1 additional kWh (and therefore $0.10 more) than the more expensive unit.

Assuming that there are 30 days in a month, you find that during the summer you are operating the air conditioner: 5 mo. x 30 days/mo. x 8 hr/day = 1200 hours [(1200 hrs x 200 watts) / (1000 watts/kW)] x $0.10/kWh = $24.00 Since the more expensive unit costs approximately $100 more, this means that it will take about four years for the more expensive unit to break even. Not all BTU ratings can be trusted. Just because the BTU's are stated to be high on specific models, this does not mean it is necessarily true. Some manufacturers will exaggerate the BTU's on units to raise the possibility of selling them and others will be more conservative to cause lower EER ratings, so keep in mind that a low room air conditioner EER may be misleading. It is best not to allow the energy rating to be your only criteria for choosing an air conditioning unit. Research the unit you are considering for your home and you will be happier with your purchase. Here you'll find a helpful Portable Air Conditioner Buying Guide .