Air Conditioning

Air Conditioning systems - heating, cooling and dehumidification of indoor air for thermal comfort

ASTM B 280 Copper Tube for Air Conditioning and Refrigeration - ACR

Standard specification for seamless copper tube for Air Conditioning and Refrigeration Field Service

Air Conditioner Efficiency

The ratio between heat removed - to watt of power used - EER and SEER

Air Conditioning - Cooling of Air and Condensate

Water may condensate when air is cooled in an air conditioning system

Ammonia - NH3 - Concentration in Air and Health Symptoms

Ammonia and health symptoms - smell and threat to life

Ammonia - NH3 - Properties

Thermodynamic properties of saturated and superheated ammonia R-717 - specific volume, enthalpy and entropy

Calculating Cooling Loads

Calculating chiller and cooling tower refrigeration - in tons

Chilled-Water Systems

Chilled-water systems equations - evaporator and condenser flow rates

Comparing Ethylene Glycol and Propylene Glycol

Properties of ethylene glycol and propylene glycol

Compressor Capacity and Evaporation Temperature

Evaporation temperatures, condensing temperatures and compressor capacities

Cooling Load Converting - kW/ton to COP or EER

How to convert cooling load between kW/ton, COP and EER

Cooling Loads - Latent and Sensible Heat

Latent and sensible cooling loads to consider in design of HVAC systems

Cooling and Heating - Performance and Efficiency Terminology

Performance and efficiency terminology related to heat pumps and air condition systems

Cooling and Heating Equations

Latent and sensible cooling and heating equations - imperial units

Dehumidfication Process in a Psychrometric Chart

Dehumidification tutorial with psychrometric charts


Classification of dehumidifiers

Equivalent Diameter - Rectangular and Circular HVAC Ducts

Equivalent diameter for rectangular and circular ducts - air flows between 100 - 50,000 cfm

Ethylene Glycol Heat-Transfer Fluid

Freezing point, viscosity, specific gravity and specific heat of ethylene glycol based heat-transfer fluids, or brines

Freeze Protection of Water based Heat Transfer Fluids

Antifreezes used in water based heat transfer fluids or brines

Fruits and Vegetables - Optimal Storage Conditions

Optimal temperature and humidity conditions for some common fruits and vegetables

HVAC Diagram - Online Drawing

Draw HVAC diagrams - Online with the Google Drive drawing tool

Heat Emission from Animals

Heat energy produced by animals

Heat Gain from Electrical Motors in Continuous Operation

Heat transferred from an electrical motor to the ambient room - different locations of fan and motor

Heat Gain from Equipment

Heat gain from switchgear, transformers, motors and more

Heat Gain from Lights

Heat contribution from lights may have a major impact on an air condition system

Heat Index

Equivalent heat index at various temperatures and relative humidities - in degrees Fahrenheit and Celsius

Heat Pumps - Performance and Efficiency Ratings

Rating the performance and efficiency of heat pumps

Heat Removed when Cooling Air

Heat removed when air is cooled to storage room conditions

Human Heat Gain

Heat gain from persons in air conditioned spaces - in btu/hr

Humidifying Air with Steam - SI units

Use steam to humidify air

Indoor Design Conditions - Industrial Products and Production Processes

Recommended indoor temperature and humidity for some common industrial products and production processes

Indoor versus Outdoor Temperatures

Recommended indoor versus outdoor temperatures

Inside Design Conditions - Summer and Winter

Recommended indoor design conditions

Lights - Installed Power

Installed light power in some common types of buildings and rooms

Measure Air Humidity with Dry and Wet Bulb Temperatures

Estimate relative humidity in moist air by measuring dry and wet bulb temperatures

Metabolic Heat Gain from Persons

Human metabolic heat gain in air conditioned rooms

Net Refrigeration Effect

The quantity of heat absorbed from refrigerated space

Outdoor Temperature and Relative Humidity - US Winter and Summer Conditions

Outdoor summer and winter design temperature and relative humidity in US states and cities

Pressure and Temperature Chart of Ammonia - NH3

A temperature (oF) and pressure (psia, psig) chart for Saturated Ammonia - NH3

R-12 Dichlorodifluoromethane Properties

Thermodynamic properties of saturated and superheated - Dichlorodifluoromethane - CF2Cl2 - specific volume, enthalpy and entropy

Refrigerant R134a Properties

Thermodynamic properties of refrigerant R-134a

Refrigerant R22 - Properties

Properties of Refrigerant R22 Dichlorodifluoromethane - saturated liquid and saturated vapor - imperial and metric units


Commonly used refrigerants - methane series, ethane series, propane series, cyclic organic compounds, zeotropic blends, azeotropic blends and organic compounds

Refrigerants - Color Codes

Refrigerants and their color codes

Refrigerants - Environmental Properties

Refrigerants - Ozone Depletion (ODP) and Global Warming Potential (GWP)

Refrigerants - Environmental Properties

Physical and environmental properties of some common refrigerants

Refrigerants - Temperature and Pressure Charts

Temperature and pressure chart for refrigerants R22, R410A, R12, R134A, R401A, R409A, R502, R404A, R507A, R408A and R402A

Refrigerants - Temperature and Pressure at Constant Boiling

Temperature and pressure diagram for constant boiling refrigerants - imperial and SI units

Refrigeration Formulas

Compression work, coefficient of performance and more

Refrigeration Machinery and required Ventilation

Ventilation required for refrigeration machinery and compressors in hot areas

Relative Humidity in Production and Process Environments

Recommended relative humidity in production and process environments - like libraries, breweries, storages and more

Required Space for Ventilation and Air Conditioning Equipment

Sizes of ventilation and air conditioning rooms according DIN 1946

Sensible Heat Ratio - SHR

Sensible Heat Ratio - SHR - is defined as the sensible heat or cooling load divided by the total heat or cooling load

Solar Heat Transmission - Type of Glass

Relative solar heat transmission through different types of glass windows

Sun Radiation through Windows

Solar heat gain through windows with roller shades, vertical blinds and Venetian blinds

Thermodynamic Properties of Refrigerant - R22

Properties of R22 - vapor volume, enthalpy and entropy at pressures from 30 to 260 psia

Water Evaporator and Condenser Equations

Air conditioner heat loads, and evaporator and condenser water flow rates

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