By Jay Fraser
In the picturesque Lowcountry of South Carolina, where the weather dances between sultry heat and balmy breezes, the importance of an effective HVAC system cannot be overstated. Developers of multi-family residential properties often find themselves toeing the line between achieving minimum HVAC code standards and creating spaces that are not just temperature-comfortable, but also humidity-controlled. The consequences of overlooking humidity control can range from mere discomfort to the growth of mildew and mold. Here, we explain why multi-family residential developers should consider additional measures for controlling humidity in their HVAC designs, going beyond the bare minimum
Right-Sizing HVAC Units
It’s easy to assume that larger HVAC units are always better at maintaining comfort levels. However, in the quest for optimal humidity control, the Goldilocks Principle applies. Meaning, you want an HVAC unit that’s sized just right for the space. Oversized units may cool the air quickly, but they often fail to adequately remove moisture. This is because proper dehumidification requires sufficient time for air to pass over cold evaporator coils, allowing moisture to condense and drain away.
Local mechanical engineers understand the nuances of climate, solar exposure, and shared walls that influence the appropriate sizing of HVAC units. For instance, two identical apartment layouts may require different HVAC unit capacities due to variations in orientation and exposure. A well-calibrated system strikes a balance between cooling capacity and dehumidification, ensuring occupants’ comfort and well-being.
Embracing Fresh Air Intake
In tightly sealed buildings with spray foam insulation, maintaining balanced air pressure becomes crucial. When exhaust fans expel air from spaces like bathrooms, it creates a vacuum that can pull unconditioned air from undesirable sources, such as crawl spaces and attics. This influx of outdoor air, with its associated temperature and humidity, can disrupt comfort and increase energy consumption.
A well-designed HVAC system incorporates controlled fresh air intake through deliberate pathways. This process ensures that outdoor air is conditioned before being distributed, maintaining both temperature and humidity levels. Properly managed fresh air intake can lead to a more stable indoor environment and a healthier living space.
Dehumidification for Comfort and Efficiency
Comfort doesn’t solely hinge on temperature; humidity plays a significant role. Often, occupants would feel more comfortable if the relative humidity were lowered, even if the temperature remained the same. Integrating a dehumidifier into the HVAC system, positioned within the ductwork, can effectively address humidity concerns and yield energy savings.
A dehumidifier, regulated by a humidistat, removes moisture from the air without pushing out cold air like an air conditioner. By setting specific relative humidity levels, occupants can experience comfort at slightly higher temperatures. This synergy between dehumidification and temperature control reduces HVAC cycle times and energy consumption, translating to long-term savings.
Embracing Variable Speed HVAC Units
Variable speed HVAC units are akin to smart grills – they adapt to demands efficiently. Unlike conventional units that are either on or off, variable speed units can adjust their motor speed between 30 and 100 percent. This adaptability allows them to cater precisely to the needs of various zones within a property.
By connecting these units to combination thermostat/humidistats and employing dampered zones, developers can offer occupants unparalleled comfort. The system adjusts its speed and airflow according to demand, optimizing both temperature and humidity control. Variable speed HVAC units epitomize intelligent technology, providing precise climate control while saving energy.
In the South Carolina Lowcountry, where humidity can be as uncomfortable as the heat itself, multi-family residential developers must look beyond minimum HVAC standards. Effective humidity control requires a thoughtful approach that encompasses proper sizing, balanced fresh air intake, dehumidification, and variable speed technology. By incorporating these additional measures, developers can create spaces that not only feel comfortable but also enhance the overall quality of life for residents. After all, a truly successful HVAC design doesn’t just regulate temperature – it ensures that humidity remains in check, fostering healthier and happier living environments.