Calculating the amount of heat or warmth that is lost from a building in winter and the amount of heat absorbed into the building in summer house building company บริษัทรับสร้างบ้าน And the electrical system will focus on helping to calculate the size of the cooling and heating of the building. It also takes into account the difference between the outdoor air temperature and the desired indoor temperature. Daily temperature variation range direction of movement of the sun Thermal resistance of wall, window, roof and functional characteristics of internal premises. with the most economical and effective principle is If we can reduce the heat loss and heat absorption of the building from the orientation of the building, how much? The less energy required for cooling or heating will be reduced. In addition, the choice of materials, insulation, and use of heat-insulating materials for cold locations to keep warm. Choosing energy-saving appliances Energy-saving analytical device for air conditioning And electric lighting has an effect as well.
amount of heat required
- The amount of heat required is equal to the amount of heat lost from the enclosed space required to maintain the temperature per hour. It is shown in the form of Btu/hr and is used as the unit to select the air conditioner size.
- One Btu (British Thermal Unit) equals the amount of heat required to raise the temperature of 1 Ib (0.4 kg) of water by 1 °F.
- Degree-day is the number of degrees of temperature difference between the average daily outdoor temperature and the desired standard temperature. To calculate the amount of heat or cooling required according to the size of the HVAC system and the amount of fuel consumption per year.
- Heating degree-day is a degree-day quantity below the desired standard temperature or 65 ‘F (19 * C) used to estimate the amount of fuel used for heating air conditioning to a higher temperature.
amount of cooling required
- The amount of cooling required. is equal to the heat absorbed into the enclosed space required to maintain the temperature per hour. It is shown in the form of Btu/hr and is used as the unit to select the air conditioner size.
- Cooling degree-day is the degree-day quantity above the required standard temperature, or 75°F (24°C), used to estimate the fuel consumption of low-temperature air conditioning. down, such as in air conditioners, refrigerators, etc.
- A ton of refrigeration is a unit of refrigeration power, where 1 ton of refrigeration equals 12,000 Btu/hr (3.5 kW), which is equal to the power to dissolve 1 ton of ice in 24 hrs. The temperature remains the same at 32 °F (0 °C).
- Energy Eficiency Rating : EER is shown in the unit of Btu/per watt of electricity supplied to the refrigeration
- For more detailed information on calculating the amount of heat and cooling required. can be read from the booklet titled Refrigerating and Air Conditioning Engineers (ASHRAE)
heat loss
heat loss from buildings in winter Mainly due to the following factors:
- Convection, radiation and heat conduction through building walls, doors, windows and roofs to the outside. including under the floor above the channel or in cold areas
- Air permeability through cracks. connected to the outside of the building especially around Windows and doors for entrance-exit
heat absorption
Absorption of heat into the building in summer caused by the following things:
- Convection, radiation and heat conduction through building walls, doors, windows and roofs to the interior when the outside temperature is high. This will be more or less depending on the temperature during the day according to the time and direction of the sun. Including the interval of time when the outside air temperature will return to the same heat again.
- Radiation through the glass of the building. There will be more or less depending on the direction of the sun. and the thermal radiation protection performance of the material to shield or protect the sun
- Number of building occupants and types of activities in that building.
- The amount of electricity, lighting and appliances that generate heat.
- Ventilation necessary to eliminate odors and air pollution.
- Latent heat decreases the heat in the air. causing water vapor in the air to condense into water droplets and make the air humidity of the indoor space is not too high
air outlet
Air conditioning with hot-cold air or ventilation systems When building a house รับสร้างบ้าน , the work of the electrical system will require a head of air supply and a mask. Air nozzles and masks are determined by size, volume and air velocity. including the wind pressure that may be reduced due to the mask potential noise and desired look
- Dispensing head and mask are not adjustable in all directions. There will be louvers at different angles to spread the wind to cover the area in all directions.
- Dispensing head and ceiling mask. It will provide low speed air flow in a manner that spreads around.
- The nozzle and the non-adjustable mask may have a longitudinal circular shape. or perforated
- The grille mask protects the air nozzle opening.
- Adjustable dispenser and mask. It controls the direction of air flow leaving the nozzle. which consists of several slats that can be adjusted horizontally as well as being able to close the shutters
- Adjustable nozzle and mask on the floor. It is used with hot air supply. To prevent heat loss and prevent condensation around windows or walls
The position of the air nozzle should allow the distribution of hot air or cold air to the floor area gently and evenly at all heights of the application area. This will prevent the area behind these things from getting cold or hot.
- Airflow distance (Throw: T) is the distance traveled by the airflow from the nozzle to a point where the airflow has decreased to a specified size. Therefore, T value depends on the initial velocity leaving the nozzle. The shape and size of the nozzle
- T value should be at least ¾ times the vertical distance of the area.
- Width (Spread: S) is the width of the airflow blown from the nozzle at the end of the airflow.
- The distance between the nozzles should be approximately equal to the amplitude of the airflow.
- Fan-shaped airflow distance S = T
- Straight-line airflow distance S = T/3
