The biggest problem with sizing your furnace and air conditioner is that so few people know how to do it accurately. The average commercial ac size ranges from 2 tons for small buildings to as much as 30 tons for very large buildings. Find out the floor space in your home. What the technician needs in addition to basic superheat knowledge are the proper modern measuring tools. 1 direct comparison with the standard and 2 indirect comparison with the standard. A btu or british thermal unit is the amount of heat needed to heat 1 pound of water one degree fahrenheit.
2 in the indirect method of measurements some transducing devise called. But body voltage measurement is an less expensive surrogate measurement that demonstrates the effect of ac electric fields on your body. According the hvac instructors interviewed taking the temperature measurements to determine the target superheat or subcooling is not that difficult. It usually contains steps on which parts of the body should be measured and the correct way to take the measurement to get accurate results. First determine square footage. Getting accurate measurements however isnt always that easy.
The most common parts of the body to be measured include but are not. Even many contractors rely on a simplified. You might be able to find the number written down somewhere or you might have to measure it yourself. 6 steps to properly size your hvac unit. To determine the approximate size of your hvac system use the following calculations. Cubic feet per minute cfm the standard measurement for calculating an air conditioners air flow is the cubic feet per minute cfm.
Body voltage measurement kit. Generally most air conditioning systems typically render 400 cfm per ton of air flow. A measurement chart is a chart used by clothiers to write down measurements of body parts needed for specific parts of the garment. Three dimensional ac electric field measurement instruments are expensive. Though btus are important most larger air conditioning units are rated in tons. A 1 ton air conditioner can remove around 12000 btu or british thermal units of heat per hour.
Bv can be used to identify which circuit breakers need to be turned off to reduce ac electric fields. The btu measurement describes the size of the unit or units in tons. Measurement location handheld manometer or pressure datalogger raw flow flow coefficientsqrtflow plate pressure corrected flow raw flowsqrt duct pressure with filter duct pressure with flow plate from paul francisco of ecotopes presentation at affordable comfort 2001. You will need to determine how many btus are required. To know what size air conditioner your building requires youll need to calculate the buildings cooling load in btu. How to figure btus for hvac sizing.
Both the methods are discussed below1 direct comparison with the standard. There are two methods of measurement. In the direct comparison method of measurement we compare the quantity directly with the primary or secondary standard.
Gallery of Body Measurement Hvac
