Pay particular attention to cooling coils, which are designed to remove water from the air and can be a major source of moisture contamination of the system that can lead to mold growth. Make sure the condensate pan drains properly. The presence of substantial standing water and/or debris indicates a problem requiring immediate attention. Check any insulation near cooling coils for wet spots.
Just had my air ducts cleaned. They used a high pressure air hose in all the heat ducts and cold air returns. He showed me the stuff that came out, the reason for the duct cleaning was the fact that I had a problem. With rodents. There was quite a few mummified rats and mice, and he said I wouldn’t have to have them done again unless I incur another problem or have renovations done. Cost me 345.00 for a 2 storey large old home. Not a bad price as I had them done when I moved in 28 years ago and it cost me 500.00. Lots of dog hair, toys, balls and assorted goodies came out as well. Took them 2 hours. I did have sanitizer put in the ducts because of the dead rodents.
The same holds true for the evaporator coils inside your home’s cooling system. Evaporator coils cause condensation, dehumidifying the air before it circulates through your home. Condensed moisture can cause dust and other particles to stick to and build up on the coils. Also, cleaning the collector pan (and the drain spout in the pan) beneath the coils ensures dirt doesn’t build up and get drawn into the system. It also prevents water from accumulating on and beneath the coils, which can cause mold problems.
The original furnace was a coal fired “octopus” design which had no blower to circulate the air but relied upon warm air rising to distribute the heat. That also means that the system breathed air in from the basement and most of this type did not have a cold air return system. At some point (probably in the 1940’s) the system was upgraded to a forced air gas furnace. The upgrade included replacing the 12″ diameter air ducts exposed in the basement with 6″ ducts and a cold air return system of ducts from the two (only two) air returns on the first floor.
The headache started with a Groupon purchase. Service for an air duct cleaning was purchased and scheduled. When the guy arrived he attempted to say that the purchase was only for a vacuuming of the vents and not a duct cleaning. Despite showing him the groupon he refused to do service. We then contacted Jennifer at this company and eventually got on a three way call with groupon who agreed with us that the service was for a complete air duct cleaning and not just using a hand vacuum to clean vents (something we could do any time). Jennifer has since hung up on my wife twice despite being civil and merely asking for the services we paid for. Unprofessional.
It’s 11 years plus in the industry I have only had to sanitize two systems both were slab systems that were in concrete and could be cleaned with a different method than normal duct cleaning. We were able to use water to rinse out the disinfectant. Would you use a chemical on anything else you use to eat or drink with and not rinse it off? The ducts in your home should be thought of as your homes heart and lungs and breathe the same air that you do. And just like us we wouldn’t use bad chemicals in our lungs and heart.
Moisture can enter the duct system through leaks or if the system has been improperly installed or serviced. Research suggests that condensation (which occurs when a surface temperature is lower than the dew point temperature of the surrounding air) on or near cooling coils of air conditioning units is a major factor in moisture contamination of the system. The presence of condensation or high relative humidity is an important indicator of the potential for mold growth on any type of duct. Controlling moisture can often be difficult, but here are some steps you can take:
A thorough visual inspection is the best way to verify the cleanliness of your heating and cooling system. Some service providers use remote photography to document conditions inside ducts. All portions of the system should be visibly clean; you should not be able to detect any debris with the naked eye. Show the Post-Cleaning Consumer Checklist to the service provider before the work begins. After completing the job, ask the service provider to show you each component of your system to verify that the job was performed satisfactorily.
Duct cleaning generally refers to the cleaning of various heating and cooling system components of forced air systems, including the supply and return air ducts and registers, grilles and diffusers, heat exchangers heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air handling unit housing (See diagram).