L-Climate psychrometry(1)

D. Amount of rainfall

Q_s = m_a C_pa (T_R - T_S)

It is the temperature at which evaporation and condensation occur at the same rate.

The ratio of the mass flow rates A and B.

They influence the design decisions to ensure comfort and efficiency.

The fraction of the sky hemisphere covered by clouds, ranging from 0 (clear sky) to 1 (total cover).

To reduce energy cost of a building.

The temperature at which water vapor in air condenses into liquid water at constant pressure.

The dry bulb temperature decreases, and moisture may condense out of the air.

The vapour content of air, given in grams or kg of water vapour per kg of moist air.

By a hygrometer or a sling psychrometer.

The temperature at which air becomes saturated with moisture in a cooling system.

B. 1.0

Solar load.

Architectural design (passive) and building services systems (active).

Dry-bulb temperature.

Typically published by meteorological stations.

Temperature, humidity, solar radiation, and air movement.

The reciprocal of density, measured in m³/kg.

20 – 25.5 °C dry bulb; 40 – 70% RH

8 °C lower than room temperature.

Cooling coil load = m_a Δh = 0.7(57 – 32.5) = 17.15 kW.

Total amount of rain, hail, snow, or dew measured in mm per unit time.

Cooling that occurs without heat transfer, often achieved through evaporative cooling.

To evaluate air properties and describe air-conditioning processes.

A. mist

0.7 kg/s

The air temperature.

The temperature of evaporative cooling.

By a thermometer with consideration of air movement.

A pair of dry-bulb temperature (T db) and wet-bulb temperature (T wb).

Very high humidities restrict the evaporation potential.

For designing drainage systems and assessing the level of precipitation.

Using a sunshine recorder that burns a trace on a paper strip, expressed as hours per day or month.

About 5 °C.

Temperature, humidity, air movement, and precipitation.

Acts as a sensible air heater.

It increases the dry bulb temperature while potentially decreasing relative humidity.

A process that reduces the temperature of air without changing its moisture content.

It means that the greater mass flow rate is from branch B.

m_M θ_M = m_A θ_A + m_B θ_B.

To measure humidity by comparing dry and wet bulb temperatures.

It is determined based on the room ratio line (RRL).

They are essential for designing HVAC systems and ensuring thermal comfort.

Relative humidity, absolute humidity, wet-bulb temperature, or dew-point temperature.

Wind speed and direction.

Millimeters (mm) per unit time (day, month, year).

8 m x 8 m x 3 m (H).

5 kW.

The heat content of unit mass of the atmosphere, in kJ/kg, relative to 0 °C dry air.

Q_s / (Q_s + Q_L) = 5 / (5 + 1.2) = 0.806.

Moisture is removed from the air, lowering its humidity level.

How close the air will get to the coil dew point.

No heat transfer occurring between points A and B.

B. cooling and dehumidification.

High temperature and humidity.

A pyranometer.

The study of moist air properties and their changing conditions.

The process of removing moisture from the air.

m_M g_M = m_A g_A + m_B g_B.

D. Fraction of cloud cover

A constant volume, 100% fresh air system.

A little bit of winter heating.

1.2 kW.

Based on a given contact factor.

A comfortable and healthy environment for people.

Heating, cooling, humidifying, and dehumidifying.

To swing the thermometers around at a constant speed for accurate readings.

The diurnal temperature variation is small in warm-humid climates.

The maximum amount of moisture air can support at a given temperature.

By subtracting the contact factor from 1.

Rate of heat transfer = 0.75(66 – 40.5) = 19.125 kW.

To categorize different climate types based on specific criteria.

It has a major effect on building performance and energy consumption.

As continuously varying irradiance (W/m²) or as irradiance over the hour or day using an electronic integrator.

Using natural energy instead of mechanical systems and power.

Processes that involve the study of the thermodynamic properties of moist air.

To keep the bulb of the wet bulb thermometer soaked in water.

It increases the moisture content and relative humidity of the air.

The ratio (in %) of the partial pressure of water vapour in moist air to that in saturated air at the same temperature.

The study of the properties of air and water vapor mixtures.

Lack of heat (under heating) or excessive heat dissipation.

Overheating, with dry air allowing for effective evaporative cooling.

It has seasonal variations between underheating and overheating, but neither is very severe.

There is usually a large diurnal (day-night) temperature variation.