Search results
Results from the WOW.Com Content Network
The starting point in carrying out an estimate both for cooling and heating depends on the exterior climate and interior specified conditions. However, before taking up the heat load calculation, it is necessary to find fresh air requirements for each area in detail, as pressurization is an important consideration.
A sewer pipe is normally at neutral air pressure compared to the surrounding atmosphere.When a column of waste water flows through a pipe, it compresses air ahead of it in the system, creating a positive pressure that must be released so it does not push back on the waste stream and downstream traps, slow drainage, and induce potential clogs.
The CLF is the cooling load at a given time compared to the heat gain from earlier in the day. [1] [5] The SC, or shading coefficient, is used widely in the evaluation of heat gain through glass and windows. [1] [5] Finally, the SCL, or solar cooling load factor, accounts for the variables associated with solar heat load.
An attic fan installed underneath a roof. A powered attic ventilator, or attic fan, is a ventilation fan that regulates the heat level of a building's attic by exhausting hot air. A thermostat is used to automatically turn the fan off and on, while sometimes a manual switch is used. An attic fan can be gable mounted or roof mounted. Additional ...
DOAS air handling unit with heat recovery wheel and passive dehumidification. A dedicated outdoor air system (DOAS) is a type of heating, ventilation and air-conditioning system that consists of two parallel systems: a dedicated system for delivering outdoor air ventilation that handles both the latent and sensible loads of conditioning the ventilation air, and a parallel system to handle the ...
Both supply and exhaust happened through an unconditioned attic space, with exhaust air being extracted at ceiling height and air being supplied at floor level through a vertical duct. The device was found to provide sufficient ventilation air flow for a single family home and heat recovery with an efficiency around 40%.
However, they are seldom used as the actual basis of design or calculation. For example, residential ventilation rates are calculated based on area of the residence and number of occupants. [ 5 ] Non-residential ventilation rates are based on floor area and number of occupants, or a calculated dilution of known contaminants. [ 6 ]
Louvered attic vent in a gable. Modern building codes permit both vented and unvented attics in all climates, if a building is otherwise correctly constructed. [5] However, unoccupied attics should usually be ventilated [6] to reduce the accumulation of heat and moisture that contribute to mold growth and decay of wood rafters and ceiling ...