Runoff Produced Per Square Foot Of Roof

Since rainwater is collected from rooftops you will need to work out the total surface area of roof s that will be used to catch rainwater.

Runoff produced per square foot of roof.

Drainage pipe required minimum diameter. 0 gallons per minute gpm 0 cubic feet per second cfs peak runoff volume. To calculate the runoff from any given rainfall. In this example we ll assume 2 inches of rain per hour.

If you get about 10 inches of rain over the course of the spring and summer an average 1 360 square foot roof would yield 8 160 gallons of rainwater. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. Rainfall calculator english units how much water falls during a storm. Calculate surface area of your roof.

So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. Measure along the length of the house or building and along the width of the house or building in feet. Although this calculation is simple in principle the units can make it a headache. It is the middle of july in georgia and both you and your tomatoes are wilting in your yard both looking to the sky and hoping for rain.

Determine the footprint of your structure f in square feet. In this example 600 x 240 x 1 144 000 cubic inches of water divide by 231 to get the number of gallons because 1 gallon 231 cubic inches. The answer is about 623 gallons. 216 000 square inches multiplied by 2 inches of rain yields 432 000 cubic inches of rain.

The number of feet multiplied by 144 equals inches. Because of the variables pinning down exact numbers is tough. Here you can easily find how much rainwater you can collect from you roof how much you need to remove from a courtyard or how much runoff you can expect from an area of land. Use our metric system version.

So how many square feet of your roof will your pv solar system cover. Multiply the two figures together to obtain the square footage of your roof. Roof area ft2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember. Automatic overflow control directs water back to downspout when barrel is full.

However calctool s unit menus remove this issue doing all the unit conversion for you. 0 inches per hour data source. 1 of rain on 1 000 sf roof will yield 623 gallons roof area m2 x precipitation amount mm amount collected liters other water conservation calculators. You have to admit that whether you re in a drought situation or not it s hard to pass up that much of a free thing.

To work out the surface area simply multiply the length in metres by width for square or rectangular roofs. But at 20 watts per square foot a system rated to produce 2 kilowatts would cover roughly 150 square feet while a 3kw system would take up about 225 square feet.