Air Conditioning

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

ASTM B 280 Copper Tube - ACR

Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service - ACR

Air Conditioner Efficiency

Air conditioner efficiency express the ratio between heat removed to watt of power used - EER and SEER

Air Conditioning - Cooling and Condensate Generated

Water condensate in air conditioning systems

Ammonia - NH3 - Concentration in Air and Health Symptoms

Ammonia and health symptoms - smell and threat to life

Ammonia - NH3 - Properties

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

Calculating Cooling Loads

Calculating chiller and cooling tower refrigeration in tons

Chilled-Water System

Chilled-water systems formulas - evaporator and condenser flow rates

Comparing Ethylene Glycol and Propylene Glycol

Comparing the properties of ethylene glycol and propylene glycol

Converting kW/ton to COP or EER

How to convert 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 - in imperial units

Dehumidfication in Psychrometric Charts

A dehumidification tutorial with psychrometric charts


Classification of dehumidifiers

Equipment Heat Gain

Heat gain from switchgear, transformers, motors ..

Ethylene Glycol Heat-Transfer Fluid

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

Evaporation Temperature and Compressor Capacities

Evaporation temperature, condensing temperature and compressor capacities

Freeze Protection Closed Loop Systems

Antifreeze is used to freeze protect water based heat transfer fluids or brines

Freon - Dichlorodifluoromethane - R12 - CF2Cl2 - Properties

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

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 of Animals

Heat emission from animals

Heat Gain from Electrical Motors in Continuous Operation

Heat transferred from electrical motors to rooms with different locations of fan and motor

Heat Gain from Lights

Heat contribution from lights may have major impacts on air condition systems

Heat Index

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

Heat Pumps Performance and Efficiency Ratings

Rating performance and efficiency of heat pumps

Heat Removed when Cooling Air

Heat removed when air is cooled to storage room conditions

Humidifying Air with Steam - SI units

The amount of vapor - kg per cubic meter - in humid air

Indoor Design Conditions - Industrial Products and Production Processes

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

Inside Design Conditions - Summer and Winter

Recommended indoor design conditions

Lights - Installed Power

Installed light power in some common types of buildings and rooms

Measuring Air Humidity

Measuring relative air humidity with dry and wet bulb temperatures

Net Refrigeration Effect

Heat absorbed from refrigerated space

Outdoor Temperature and Relative Humidity - US Winter and Summer Conditions

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

People and Heat Gain

Heat Gain from Occupants in Air Conditioned Spaces - in btu/hr

Persons and Metabolic Heat Gain

Metabolic heat gain from occupants in air conditioned spaces at different degrees of activities - in Watts

Pressure and Temperature Chart of Ammonia - NH3

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

Radiant Heat through Windows

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

Recommended Indoor Temperature versus Outdoor Temperature

Recommended indoor effective temperatures at various outdoor dry-bulb temperatures

Recommended Relative Humidity in Production and Process Environments

Recommended Relative Humidity - RH - in production and process environments like libraries, breweries, storages and more

Rectangular and Circular HVAC Ducts - Equivalent Diameter

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

Refrigerant Color Codes

Color codes refrigerants

Refrigerant R134a Properties

Thermodynamic properties refrigerant R-134a

Refrigerant R22 - Properties

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

Refrigerant Temperature-Pressure Chart

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


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

Refrigerants - Environment Properties

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

Refrigerants - Environmental Properties

Physical and environmental properties

Refrigeration Formulas

Equations like compression work, coefficient of performance ...

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

Space required for Ventilation and Air Conditioning Equipment

Required size of ventilation and air conditioning rooms according DIN 1946

Temperature-Pressure Diagram for Constant Boiling Refrigerants

Temperature-pressure in imperial and SI units

Thermodynamic Properties of Refrigerant - R22

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

Type of Glass and Solar Heat Transmission

Relative heat transmission through glass windows

Ventilation Refrigeration for Compressors

Ventilation requirements for refrigeration machinery

Water Evaporator and Condenser Equations

Air condition load, evaporator and condenser water flow rate

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