Have you ever wondered what goes into a heating or air conditioning system for a large office building or another large building like a mall or a school? My name is Evelyn, and I am an HVAC architect. I design heating and air conditioning systems for large, corporate buildings. Making sure that a large building with many rooms or offices is efficiently heated and cooled is a very large job and is much more complicated than simply heating or cooling a home. This blog will educate the reader on how heating and cooling jobs this large are designed and completed.
While there are plenty of advantages to living in a climate that doesn't see snow or cold winters, there can also be some disadvantages. Many warmer locations in the United States also suffer from relatively high humidity, and that extra moisture can pose significant challenges for HVAC design. At a minimum, humid conditions often mean that even lower temperatures can feel subjectively less comfortable.
If you're installing a new HVAC system in a humid climate or building a home from scratch in one of these areas, you'll need to consider your local conditions. Although you can easily fill whole textbooks with this topic, this article will briefly describe three factors that can affect the efficiency, performance, and design of HVAC systems in warm, humid areas.
1. Building Envelope and Pressure Balance
Your home's air conditioning system can help control humidity levels, but issues with your home's structural envelope can undo much of its hard work. You can think of your building (or structural) envelope as the invisible shield that protects your home from the outside environment. It includes your insulation, walls, doors, and everything else that separates the inside from the outside.
Poorly balanced pressure can stress your envelope. If your home has negative pressure, it will pull humid air in from the outside. On the other hand, positive pressure can force your conditioned air out, wasting energy and efficiency. While designing a system to maintain balanced pressure is always important, it's especially crucial in humid environments where there's a risk of drawing too much moisture inside.
2. Adequate Sizing and Runtime
The simplest home air conditioning systems use single-stage compressors and blowers. These systems run at one speed and depend wholly on proper sizing to keep your space cool. With a single-stage unit, dehumidification is a function of run time. The longer the system takes the cool your house, the more humidity it can remove.
In humid environments, oversized systems can be far more problematic than undersized ones. A too-large system will run in short bursts, cooling your home quickly but failing to remove humidity. This situation may force you to turn down your thermostat further, wasting energy and stressing your system. As a result, proper sizing is especially crucial in humid areas.
3. Additional Dehumidification
Some environments are so humid that a properly sized air conditioner won't provide sufficient runtime for full dehumidification. In these cases, you may not be able to achieve comfortable interior temperature and humidity levels. If your contractor doesn't believe your system will be able to keep your home comfortable, they may recommend some additional steps.
In most cases, the best option is to add a whole-home dehumidifier. A whole-house dehumidifier can remove moisture without affecting temperature, allowing you to keep your thermostat at a comfortable level without leaving your home feeling humid and sticky.
To learn more, contact an HVAC contractor in your area.