Regional climate plays a large role in Indoor Air Quality and comfort. Regional climate characteristics are determined by geographic location and long term weather conditions. Two of the most important factors that affect an areas climate are temperature and precipitation.
What makes Humid Climates Uncomfortable?
Humid climates have a high amount of water vapor in the air. When it’s hot, high humidity makes people feel hotter because it reduces the ability to evaporate moisture from the skin. In humid climates, becoming comfortable means going into a conditioned space.
Potential for Mold Growth
While mold spores are in every region and every climate, mold growth is highly dependent on the amount of humidity. Mold growth typically occurs when an environment reaches a relative humidity of 60 percent or greater in a 72 hour span. If mold is found within your home or workplace remediate the problem immediately, mold spores can be distributed throughout the home or building through the HVAC system impacting indoor air quality.
Air Conditioning in Humid Climates
Air conditioning coils serve a very important role in regulating temperature and humidity in humid climates. As air passes through the evaporative coil of the air conditioner, heat and moisture are removed from the air. To a degree, the lower the humidity level, the more comfortable you will feel at a given temperature.
Air Duct Cleaning and HVAC Maintenance
Overtime foreign debris is drawn into the evaporative coils and fan blower of the air conditioning system, gradually decreasing air flow and energy efficiency. Maintaining HVAC system, will keep your cooling and heating components operation at peak energy efficiency, and prevent potential indoor air quality problems. Yearly air conditioner inspections and routine air duct cleaning with assure maximum efficiency.
For decades the National Air Duct Cleaners Association (NADCA), has been educating consumers on the process and benefits of air duct cleaning. Currently there is research study underway to measure the correlation between energy pressure drop and energy savings.
NADCA Energy Research Study
In February 2008, NADCA entered into a partnership with the Colorado University to conduct a research project that will provide members with a tool for estimating the energy savings associated with HVAC cleaning and restoration projects. The research project was also commissioned to develop a field-testing protocol for NADCA members that will facilitate collection of data to provide broader support for linking HVAC cleaning and restoration to energy savings.
Current Findings and Test Results
NADCA presented the current results of the test at the 2010 Annual Meeting. Comparisons were made by testing air flow rates when the filter, furnace, and evaporative air conditioner coil were fouled and again when the components were clean.
It was found that a dirty filter increased the filter pressure drop, system pressure drop and reduced the air flow of the ventilation system.
Surprisingly, a clean furnace and evaporative air conditioner coil increases initial energy consumption, but lessoned the amount of time that the furnace an air conditioner had to operate to achieve the desired room temperature. Though there was initial higher energy consumption, there was a net gain in overall energy efficiency.
While further data and testing is required, the current the findings show that proper exchange rate and selection of the furnace filter, routine cleaning of the evaporative air conditioner coil, and sealing of air ducts offer the greatest benefits to energy savings.
Further Testing Underway
Currently NADCA is receiving further test results from companies engaged in the assessment, cleaning, and restoration of HVAC systems. These test results are being sent to the University of Colorado for further interpretation.
Ensuring good indoor air quality is easy once you have an understanding of the components that effect your homes environment. Using the steps below, perform a quick checklist to improve your indoor quality.
Setting the Standard for Indoor Air Quality
ASHRAE, the American Society of Heating, Refrigeration and Air Conditioning Engineers developed Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. The standard, which is widely accepted by green builders, state and local around the counties, defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope in order to provide acceptable IAQ in low-rise residential buildings.
10 Steps to Ensure Good Indoor Air Quality
- Vent bathrooms, kitchens, toilets and laundry rooms directly outdoors. Use energy efficient and quiet fans.
- Avoid locating furnaces, air conditioners and ductwork in garages or other spaces where they can inadvertently draw contaminants into the house.
- Properly vent fireplaces, wood stoves, and other hearth products; use tight doors and outdoor air intakes when possible.
- Vent cloths dryers and central vacuum cleaners directly outdoors.
- Store toxic or volatile compounds such as paints, solvents, cleaners, and pesticides out of the occupiable space.
- Minimize or avoid unvented combustion sources such as candles, cigarettes, indoor barbecues, decorative combustion appliances or vent free heaters.
- Provide operable windows to accommodate unusual sources or high-polluting events, such as the use of home cleaning products, hobby activities, etc.
- Use sealed-combustion, power-vented or condensing water heaters and furnaces. When natural-draft applications must be used, they should be tested for proper venting and should be located outside the occupied space when possible.
- Put a good particle filter or air cleaner in your air handling system to keep dirt out of the air and off your ductwork and heating and cooling components.
- Distribute a minimum level of outdoor air throughout the home using whole-house mechanical ventilation.
Source: ASHRAE Standard 62.2 Ventilation and Acceptable Indoor Air Quality on Low-Rise Residential Buildings, and 2001 ASHRAE Handbook, Fundamentals, Chapter 26, Ventilation and Infiltration.