I know there are a lot of possible factors that go into determining the size of the air-conditioning system a house needs. Is there a standard way of calculating what is needed, or do A/C companies each devise their own method? Is there a guide somewhere to aid a home-owner in figuring it out? You'll want to check out the ENERGY STAR Air Conditioning Sizing Calculator. To roughly calculate the required BTU output of an air conditioner you will need to total up the results of six calculations. Square footage of area to be cooled. (Length x Width) x 337 Area of south facing windows. (Height x Width) x 871 Area of north facing windows. (Height x Width) x 166 Heat produced by people (# of people x 400) Heat produced by lights (Total wattage of all lights x 4.25) Total heat produced by appliances (Total wattage of all appliances x 3.15) Add all of these numbers up to determine the BTU output required of the air conditioner (Source).

You could also use a site like this Air Conditioner Sizing Worksheet to make the calculations. It probably depends on climate as much as it does the square footage of your house but the general rule is one ton for every 400-500 square feet of house. There are a ton of other factors like vaulted ceilings and if you have dual pane windows and if you have 2x6 construction and therefor more insulation in the walls but for the most part none of that is going to factor into the unit. It goes more like this: Contractor: How big is your house? You: about 1900 square feet Contractor: I see the house is older You: Yeah, it was built in the 50s Contractor: 5 ton it is! Contractor: I see the house is newer You: Yeah, it was built in the 90s I think you need to look at the Discover Ways for Air Conditioner Sizing in order to get an idea of the size of the AC unit. Two out of three suggested methods include Manual J which is exact science - but not many contractors want to do it for free.

There's a ton of variables: A good HVAC pro will be able to do the proper calculations for you.Online Tonnage calculator helps you to determine the AC tonnage required for a particular room. Wall thickness - 9 inch, Colling thickness - 6 inch, Room height - 10ft or less, Indoor Temperature - 24~25 deb. Col, 2how to refill window ac unit Persons, 01 TV & 01 computer in room, room should be single & air tight, curtain on glass window,outside ac unit running winter installation by LG authorised person,5 ton ac unit coverage This is only for general guidance and is not a rule book. Random samples taken for testing. Outside ambience like location near sea, drains, installation in shaft, air moisture level have not been considered.

How do you convert air conditioner BTUs to tons? To convert BTUs to tons, find the BTU capacity of the air conditioner, and divide the BTUs by 12,000. Twelve thousand BTUs equals the amount of heat removed by an air conditioner that would melt 1 ton of ice in 24 hours, which is called the chiller refrigeration ton, according to The Engineering Toolbox. How many BTUs do I need to air condition 600 square feet? Find the BTU capacity On the tag or packaging, find the BTU rating of the air conditioner. The number is expressed in thousands, such as 6,000 BTU or 15,000 BTU.Divide the BTUs by 12,000Using a calculator, divide the unit's BTU rating by 12,000 to arrive at the chiller refrigeration ton capacity. The equation may yield a fraction. For instance, a 6,000-BTU window air conditioner equals 1/2 ton of cooling capacity. Apply the tonnage to the spaceAn old rule of thumb stipulated that 1 ton of air conditioning should cool 400 square feet of living space. However, many air conditioners are too large for the site, which results in high humidity and wasted energy.

The current thinking, according to Green Building Advisor, is 1 ton per 1,000 square feet of space, with some adjustments based on ceiling height, climate, number of windows and other variables. What material is an air conditioner grate made from? How does a manometer work? What are the top 10 brands of air purifiers? What is the size of a standard 2 car garage? How fast can a Concorde plane go? Room Dimensions (in ft.) Area of Windows (in sq. ft.) Is your floorBasement or Ground Floor First or Higher Floor Are there any floor(s) above yours Yes Number of people occupying the area Calculating chiller and cooling tower refrigeration - in tons Cooling towers tons pairs the water-cooled chiller tons and the water-cooled condenser tons.  Chiller Refrigeration Tons The process of cooling is called refrigeration. Refrigeration or cooling capacity can be measured in tons. A water-chiller refrigeration ton is defined as: 1 Refrigeration Ton (RT) = 1 TONScond = 12000 Btu/h = 200 Btu/min = 3025.9 k Calories/h = 12661 kJ/h = 3.517 kW 1 kW = 0.2843 Refrigeration Ton (RT) A ton is the amount of heat removed by an air conditioning system that would melt 1 ton (2000 lbs.) of ice in 24 hours.

The heat required to melt 1 lb of ice at 32 oF to water is 144 Btu. 1 Ton Refrigeration = (2000 lb) (144 Btu/lb) / (24 hr)     = 12000 Btu/hr Converting between Btu/h and Tons of Refrigeration Btu/h Refrigeration Ton 6000 1/2 12000 1 18000 1 1/2 24000 2 30000 2 1/2 36000 3 42000 3 1/2 48000 4 54000 4 1/2 60000 5 Cooling Tower Tons A cooling tower ton is defined as: 1 cooling tower ton = 1 TONSevap = 1 TONScond x 1.25 = 15000 Btu/h = 3782 k Calories/h = 15826 kJ/h The equivalent ton on the cooling tower side actually rejects about 15000 Btu/h due to the heat-equivalent of the energy needed to drive the chiller's compressor. This equivalent ton is defined as the heat rejection in cooling 3 U.S. gallons/minute (1500 pound/hour) of water 10°F, which amounts to 15000 Btu/hour, or a chiller coefficient-of-performance (COP) of 4.0 - a COP equivalent to an energy efficiency ratio (EER) of 13.65. Heat Load and Water Flow A water systems heat load in Btu/h can be simplified to: h = cp ρ q dt     = (1 Btu/lbm oF) (8.33 lbm/US gal) q (60 min/h) dt     = 500 q dt         (1) where h = heat load (Btu/h) cp = specific heat, 1 (Btu/lbm oF) for water ρ = 8.33 (lbm/US gal) for water q = water volume flow rate (US gal/min) dt = temperature difference (oF) Example - Water Chiller Cooling Water flows with