Units in HVAC

In HVAC (Heating, Ventilation, and Air Conditioning) systems, capacity refers to the system’s ability to heat or cool a space. The most common units for measuring HVAC capacity are BTU (British Thermal Unit) and kW (kilowatt). In the following paragraphs, we will explain these units in HVAC systems.

BTU (British Thermal Unit)

A BTU is a unit of heat energy. It is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. BTUs are commonly used in the United States to describe the capacity of heating and cooling systems. For example, an air conditioner might be rated at 12,000 BTU per hour, indicating it can remove 12,000 BTUs of heat from a space each hour.

KW (Kilowatt)

A kilowatt is a unit of power equivalent to one thousand watts. It measures the rate of energy transfer or conversion. Kilowatts are more commonly used internationally and in scientific contexts. In HVAC systems, kW can describe the electrical power consumption of the system or its heating/cooling capacity. For instance, a heater with a capacity of 3 kW can generate 3 kilojoules of heat energy per second.

Converting Between BTU and kW

To convert between these units, you can use the following relations:

– 1 BTU per hour (BTU/h) = 0.000293071 kW

– 1 kW = 3412.142 BTU per hour (BTU/h)

Ton

Another common unit in HVAC, especially for air conditioners, is the ton. One ton of cooling capacity is equivalent to 12,000 BTU per hour. This term originates from the amount of heat required to melt one ton of ice over 24 hours.

SEER (Seasonal Energy Efficiency Ratio)

This measures the efficiency of air conditioners and heat pumps. It is the ratio of the cooling output (in BTU) over a typical cooling season divided by the total electric energy input (in watt-hours) during the same period.

COP (Coefficient of Performance)

This measures the efficiency of heating systems. It is the ratio of useful heating or cooling provided to the energy consumed. Higher COP values indicate more efficient systems.

These terms and units are essential for comparing the capacities and efficiencies of different HVAC systems, helping users select the right equipment for their needs. In Radiran the required capacity of the customer’s system can be calculated and the desired equipment can be designed and manufactured based on the capacity they need.