How do you calculate refrigeration capacity?
Divide Q (BTUs per hour) by 12,000 (the number of BTUs in one ton of cooling capacity). This yields the chiller capacity required to handle the process heat load in tons per hour: Example: 240,000/12,000= 20 tons/hr.
What is capacity control in refrigeration?
Capacity control of a refrigeration plant can be defined as a system which monitors and controls the output of the plant as per the load on demand. As the load (temperature) of one room is reached to its required temperature, there will be no more need of the refrigerant for cooling.
How do you calculate 1 ton of refrigeration?
One ton of refrigeration is equal to 3024 kilo-calories per hour. This is 12,000 BTU/ h divided by 2.204 (pounds per kilogram) divided by 1.8 (°C to °F).
How do you calculate HVAC capacity?
To calculate the estimated HVAC load for a house with 2,500 square feet, 12 windows, and 3 exterior doors occupied by 4 people, simply plug it into this formula: 2,500 x 25 = 62,500 base BTU. 4 people x 400 = 1,600. 12 windows x 1,000 = 12,000.
What is the formula for CoP?
CoP = power output / power input. The higher the number, the more efficient the system.
How do you calculate evaporator capacity?
If the evaporator must move 400 gallons per minute: 14 x 400 = 5,600. Multiply the answer by 500: 5,600 x 500 = 2,800,000. This answer is the evaporator’s size, measured in BTUs per hour. Divide the answer by 12,000: 2,800,000 / 12,000 = 233.33.
What are 4 types of compressor capacity control?
Compressor capacity-control methods are utilized to maintain a required compressed gas delivery under variable process conditions. The main capacity control methods for reciprocating compressors are variable-speed drives, suction valve unloaders, step-less methods, clearance pockets and bypass recycling.
How is capacity control accomplished?
INTRODUCTION Capacity control of a reciprocating compressor can be accomplished directly by varying the speed or by methods designed to allow direct discharge of vapor from a cylinder to the low pressure or suction side during the so-called compression stroke.
What is the formula to calculate tonnage?
tonnage, in shipping, the total number of tons registered or carried or the total carrying capacity. Gross tonnage is calculated from the formula GT = K1V, where V is the volume of a ship’s enclosed spaces in cubic metres and K1 is a constant calculated by K1 = 0.2 + 0.02 log10 V.
How do I calculate BTU for refrigeration?
Step 1: Measure The Square Footage (Length, Width, Height Exact To 0.25 Ft)
- Square Footage = Measured Length x Measured Width.
- Square Footage = 16 3/4 ft (Length) x 14 1/2 ft (Width) = 243 sq ft.
- BTU Requirement = 500 sq ft x 20 BTU per sq ft = 10,000 BTU.
- Accurate BTU Calculation = 20,000 BTU * 1.1 + 600 BTU = 22,600 BTU.
What is HVAC system capacity?
Capacity refers to the ability of a heating or cooling system to heat or cool a given amount of space and is measured in tons. Cooling capacity is expressed in tons. A ton is the capacity in relation to melting one ton of ice in 24 hours.
What is a good COP value?
A good COP for heat pump units starts at about 2.0 for an air source heat pump and about 3.1 for geothermal, but heat pump COP can be well above 4.0 too, as seen in the chart below. A geothermal heat pump is also called a ground source heat pump.
What is a COP value?
A COP value of 3 means that you get 3kWh of heat output for every 1kWh of electricity used to run the pump. Higher COP values represent a heat delivery that is relatively more efficient. For example, a COP value of 4 means that you get 4kWh of heat output for every 1kWh of electricity used to run the pump.
What is the formula for calculating BTU?
You may be familiar with the formula BTUH = CFM x ΔT x 1.08. This same formula is often rearranged to use for determining airflow by measuring the heat input and temperature rise.
What is evaporator capacity?
Explanation: The evaporator capacity is defined as the amount in kg of steam used to heat the fluid for evaporation in 1hr.
How do you control the capacity of a compressor?
Adding and subtracting fixed clearance is one of the most common methods used to control the capacity of a reciprocating compressor. When fixed clearance is added to the compression chamber of a compressor cylinder the VE is reduced thus reducing capacity. This is an efficient method of capacity control.
Why is capacity control important?
Capacity control
The two main reasons why a reciprocating compressor capacity regulation is used are to adjust the suction mass-flow to match the process demand and to save energy. Variable-speed reciprocating compressors are attractive, theoretically. However, they have many practical, technical and cost limitations.
What are some approaches to compressor capacity control?
What is tonnage factor?
The tonnage factor provides the mechanism for the conversion from volume of ore to weight of ore. In the English system, the tonnage factor is normally expressed as cubic feet per ton of ore. In the metric system, the tonnage factor is the specific gravity of the ore.
How many CFM are in a BTU?
The BTU’s per hour unit number 163.17 Btu/h converts to 1 atm cfm, one atmosphere cubic foot per minute. It is the EQUAL power value of 1 atmosphere cubic foot per minute but in the BTU’s per hour power unit alternative.
How do I calculate cfm?
CFM = (fpm * area), where fpm is the feet per minute. To find the cubic feet per minute, substitute the FPM value with the area after the area is squared.
What is cooling capacity in kW?
The cooling capacity is defined as the amount of cooling (usually expressed in terms of kW or tons of cooling) delivered by the system divided by the amount of air passing through the system (in kg/s or cfm).
What is the formula for COP?
Why can COP be greater than 1?
The COP usually exceeds 1, especially in heat pumps, because, instead of just converting work to heat (which, if 100% efficient, would be a COP of 1), it pumps additional heat from a heat source to where the heat is required.