About Indoor Air Quality (IAQ)

    Advanced Services knows what it takes for quality indoor air. While your HVAC unit may being doing great keeping your home or business comfortable, the air quality of your home or business may not be proper or adequate.

    Indoor Air Quality is another science when dealing with your HVAC system. Proper humidity, ventilation, filtration and additional equipment may be necessary to maintain proper indoor air quality.

    When dealing with indor air quality, a strategic approach must be taken. Advanced Services takes a 3-step approach to improve indoor air quality.


    Improper humidity levels can cause poor indoor air quality in your home or business. Your HVAC system may not properly humidify or dehumidify your home or business if they are not operating at maximum efficiency.

    Humidity refers to the amount of moisture in the air. Relative humidity (RH) is the percentage of water vapor in the air at a specific temperature compared to the amount of water vapor it is capable of holding at that temperature. Humidity is a factor of thermal comfort. Rising RH reduces the bodies ability to lose heat through perspiration and evaporation (similar to raising the temperature).

    High humidity conditions (primarily occurs in the summer months) can result in persons feeling wet and clammy. RH levels exceeding 50-60% can promote mold growth, increase dust mites, and musty odors that can exacerbate allergies and asthma. High humidity can especially be a problem in new construction where internal walls are mostly made from paper-faced wallboard instead of wood or plaster which are more mold-resistant. ASHRAE 62.1-2007 states "Occupied space RH shall be limited to 65% or less." Dehumidifiers, heat and ventilation are the best way to reduce humidity levels particularly in basements and crawl spaces. These units can be connected to an external drain to promote continued operation.

    Low humidity conditions (primarily occurs in winter months) can dry the eyes, nose and respirator passages and increase building occupants susceptibility to upper respiratory infections and colds. Low humidity levels can also cause skin irritations and can also make you feel cooler resulting in the desire to turn the thermostat up. Static electricity problems affecting the hair and synthetic fiber clothing are good indications of an office with low RH (about 40% RH). Studies indicate odors become more objectionable at 30% RH and below. Contact lens users also have discomfort in low RH.


    Proper ventilation is vital to a properly designed HVAC system and indoor air quality. Poor indoor air quality may occur when there is not enough fresh air introduced into the conditioned space to reduce contaminant concentrations. Also, poor indoor air quality can occur when there is not proper exhaust ventilation in bathrooms and kitchens. The existence of still or stale air, odors and draftiness can lead to poor indoor air quality. A proper HVAC system must deliver proper outside air evenly for the occupants of the structure. Poorly ventilated structures efficiently spread communicable diseases like the common cold, influenza and tuberculosis. Residential structures require less ventilation than commercial structures. Introducing fresh air ventilation may increase the size of the HVAC system.


    Proper filtration is vital to a properly designed HVAC system and indoor air quality. Most filters in your common HVAC system are to keep the equipment, such as the indoor coil, from getting dirty. This is a great way to help keep your equipment protected if the filters are properly changed at the required intervals. But as far as indoor air quality goes - these filters may have little to no effect on the indoor air quality. Actually, some filters may cause too great of a restriction to the airflow in your HVAC system - which could cause problems or reduce the lifespan of your system.

    Filters can come in the form of standard-efficiency to high-efficiency. Most common panel filters are of the doghair type or pleated material. Medium to high-efficiency filters have a thicker filtration media or more surface area to provide filtration.

    HEPA Air Filtration systems can remove chemical vapors, particles, germs and and odors - depending on the style of HEPA Air Filtration system used.

    Filters may have an industry-created standard associated with them which is called MERV (Minimum Efficiency Reporting Values). The lower the MERV rating, the less efficient the filter is at filtering particles. While you may want to use a high MERV rating filter, this may not be the best choice due the the restriction of airflow the filter may cause. A HVAC and duct system must be properly designed to allow proper airflow with high MERV rated filters.

    A proper filtration system must be designed to meet the needs and usage of the conditioned space. Some filtration systems must be incorporated into the duct system to achieve optimum perfermance.

Air Cleaners

    High-efficiency filters such as electronic air cleaners use an electrical charge to trap particles on metal plates that must be periodically cleaned after the plates become full of particulates. The electronic air cleaners provide dust and particulate filtration. Some systems may require a pre-filtration unit before the electronic air cleaner to prevent snapping and popping sounds from the electronic air cleaner trying to do excessive work. Electronic air cleaners can help eliminate pet dander smell and mold spores.

UV Lights

    Ultraviolet lights can destroy germs, viruses, bacteria, mold, chemicals, odors and much more.

    UV lights work great but may require more routine maintenance. The UV bulbs can last from one year up to 3 years. The UV lights must be placed in strategic places and installed in accordance with manufacturers specifications to be effective.

Proper Maintenance

    Properly maintaining your HVAC and IAQ accessories will improve indoor air quality. Your HVAC system may not properly humidify or dehumidify your home or business if they are not operating at maximum efficiency. Improper humidity levels can affect the comfort and indoor air quality of your home or business. Dirty coils & filters and improperly maintained HVAC systems and IAQ accessories can affect the indoor air quality of your home or business.

    While dirty coils can affect indoor air quality, they can cause high refrigerant pressures which leads to reduced compressor life. They can also cause liquid refrigerant floodback to your compressor, which harms your compressor.

Proper Routine Indoor Cleaning

    Routine indoor cleaning is vital to indoor air quality. Your HVAC system will circulate air throughout your home or business and any dust, smoke and any odors contained in your home will be circulated through the duct system and home or business.

    Your filtration and any IAQ accessories contained in your HVAC system will require less work when your home or business is properly and routinely cleaned. Using green or low-VOC (Volatile Organic Compound) cleaners is recommended.

The Visuals of IAQ

HVAC Dirty Clean Coil

Coil Conditions

Dirty indoor coils can be a breeding ground for mold, organisms and odors.
HVAC Dirty Filter


Dirty filters can be lead to poor indoor air quality and HVAC system failures.

IAQ Accessories


UV Lights

Ultraviolet lights can destroy germs, viruses, bacteria, mold, chemicals, odors and much more.
HVAC Electronic Air Cleaner

Electronic Air Cleaners

Electronic air cleaners use an electrical charge to trap particles on a metal plate.

MERV Ratings

Click to enlarge

MERV Ratings