When designing an air conditioning system, it is essential to take into account a variety of factors in order to ensure the system is effective and efficient. These factors include building size and design, local climate, energy efficiency, indoor air quality, maintenance and serviceability, cost, occupancy and use, zoning, noise, sustainability, regulatory and code requirements, and future expansion. In humid climates, the air conditioning system must be designed to maintain humidity control. This means pressurizing the building with dehumidified air and properly conditioning the interior of the building. The Florida Solar Energy Center (FSEC) has found that building pressures as low as +1 Pascal (Pa) relative to outdoor conditions are sufficient to prevent outdoor air infiltration problems.
However, even a slightly depressurized building (-1 Pa relative to normal outdoor conditions) in hot and humid climates can cause moisture and microbial growth issues due to the intrusion and condensation of humid outdoor air. To avoid this issue, the air conditioning system must positively pressurize the space of a building by supplying unconditioned or only partially conditioned outdoor air. One of the most important causes of moisture buildup in existing buildings in hot, humid climates is the overemphasis on ventilation at the expense of adequate dehumidification. The comparison of the latent and sensitive loads of several major cities in different geographical regions helps to illustrate this concept. For example, during the cooling season in Orlando (Figure 2A), the latent load far exceeds the sensitive load of outdoor air.
This means that any outdoor air that enters the building envelope or occupied space is likely to cause problems with moisture accumulation and microbial growth. To address this issue, air conditioning systems must provide sufficient dehumidification while reacting only to temperature control. This can be achieved through reheating or by using a desiccant that draws moisture from the air to its surface by introducing a low vapor pressure to the surface of the desiccant. The desiccant must then be recharged through a heating process which allows moisture to leave the desiccant and be discharged to another location in addition to the cooling air stream. The pressurization of the building must also be taken into account when designing an HVAC system. The design team must consider how air exhaust systems will affect space pressures and if the system can provide sufficient dehumidification without affecting indoor temperature or occupant comfort.
The main factors for optimizing energy efficiency are ventilation, zone control, heat recovery and operations. Ease of maintenance and ease of service are also essential factors in designing an HVAC system. When it comes to designing an HVAC system for a building, there are several important factors that need to be taken into consideration. These include building size and design, local climate, energy efficiency, indoor air quality, maintenance and serviceability, cost, occupancy and use, zoning, noise, sustainability, regulatory and code requirements, and future expansion. In humid climates, it is essential for an HVAC system to maintain humidity control by pressurizing the building with dehumidified air and properly conditioning its interior. The Florida Solar Energy Center (FSEC) has found that building pressures as low as +1 Pascal (Pa) relative to outdoor conditions are sufficient to prevent outdoor air infiltration problems.
However, even a slightly depressurized building (-1 Pa relative to normal outdoor conditions) in hot and humid climates can cause moisture and microbial growth issues due to humid outdoor air intrusion and condensation. To avoid this issue, an HVAC system must positively pressurize a building's space by supplying unconditioned or only partially conditioned outdoor air. One of the most common causes of moisture buildup in existing buildings in hot climates is an overemphasis on ventilation at the expense of adequate dehumidification. The comparison of latent and sensitive loads of several major cities in different geographical regions helps illustrate this concept. For example, during Orlando's cooling season (Figure 2A), its latent load far exceeds its sensitive load of outdoor air.
This means any outdoor air entering a building envelope or occupied space is likely to cause moisture accumulation and microbial growth issues. To address this issue, an HVAC system must provide sufficient dehumidification while reacting only to temperature control. This can be achieved through reheating or by using a desiccant that draws moisture from the air to its surface by introducing a low vapor pressure. The desiccant must then be recharged through a heating process which allows moisture to leave it and be discharged elsewhere in addition to the cooling air stream. The pressurization of a building must also be taken into account when designing an HVAC system. The design team must consider how exhaust systems will affect space pressures and if they can provide enough dehumidification without affecting indoor temperature or occupant comfort.
Other important factors for optimizing energy efficiency include ventilation, zone control, heat recovery and operations; as well as ease of maintenance and serviceability.
