Allergies and the HVAC system

adminHome Inspection Tips, Allergies, HVAC Leave a Comment

What do allergies have to do with the HVAC system?

Allergies are a very common thing with many people of all ages but most are attributed to food and nature.

What about the environment in our home? Multiple allergens can be found inside a home. These include mould, dust mites, pet dandruff, cockroaches, mice, etc. All these can play a huge role and can affect people in different ways. These allergies can trigger upper respiratory system reactions like asthma, sinus issues, skin irritations, etc.

The first thing a person should do is of course see their family doctor as the symptoms have to be treated. Like in every other situation, the law of cause and effect applies here also. What is the cause of the allergies?

I have been in many homes where a member of the family is complaining about allergic reactions and the first area, I will go to is the utility room of the house. Most Canadian homes have a forced-air heating system, which includes the furnace component and the distribution component.

Cleaning of ducts and registers

Dirty air duct
Dirty Air Duct

The distribution component is the ducts and the registers. That is how heated air circulates in all areas of the home. If the ducts of a house have not been cleaned in a while, then dust accumulates and sticks on the walls. This is what the inside of a distribution duct looked like in one of the homes I visited.

Replacing the furnace Filter

The furnace filter condition is another indication of an unhealthy home environment. Furnace filters have to be replaced every 3 months. Some larger type filters have a replacement recommendation of 6 months. Clogged filters not only leave the air in your home dirty but will also decrease the life expectancy of your furnace. A dirty furnace will not work properly.

Old-style electronic filters and reusable filters are, in my opinion, not adequate because they do not stop small particles. I always recommend disposable good quality filters to be used and to be replaced every three months.

Maintaining the humidifier

deteriorated humidifier pad
humidifier pad needs replacement

Another component of the HVAC system that typically goes unchecked, is the humidifier. The humidifier offers the perfect environment for mould spores to thrive. A deteriorated humidifier pad will trap dust and mould spores and the water flowing through will provide the moisture needed for the mould spores to thrive.

The humidifier pad should be replaced typically every 12 to 18 months depending on the quality of the water in your area. 

Maintenance of the HRV or ARV

The Heat Recovery Ventilator or Air Recovery Ventilator is also part of the HVAC systems and is required in new construction since 2019. Many homes built before 2019 also have them installed as part of the energy conservation programs from the government. This equipment replenishes the air in your home by bringing fresh air from outside in the house and bringing stale air out. In that process though, dust, insects and mould spores will also be introduced in the indoor air, therefore a good quality high MERV filter should be used and the equipment and the internal filters cleaned every 6 months. 

What is a healthy home audit?

Air quality and environmental hazards are something that many of us take for granted.  If you don’t know what to look for then you may not know what to fix.  Our Healthy Home Audit was designed to help homeowners identify potential environmental health risks and aid you in correcting them.  We want to ensure that all the systems in your home are optimized for safety and good health.  Learn More


Can I do duct cleaning myself?

The answer is no. I recommend hiring a professional duct cleaning company to do this. A proper duct cleaning is a detailed process of blowing air in the system and using large vacuum systems, typically set up on large trucks.

Can I maintain the furnace components myself?

As a homeowner, you should be doing the first level of maintenance, which is changing the furnace filter, changing the humidifier pad and cleaning your HRV filters. The actual service of the furnace should be done only by a licensed technician.

Can I disconnect the HRV system?

 If your house was built with an HRV installed, then the answer is no. The house was built as a tight envelope and the only way to replenish the air is by using the HRV system.

Are HEPA filters any good?

HEPA filters are top-of-the-line filtration systems. I typically recommend them to homeowners who have allergies in the household. I have one installed in my home as well. They are costly and also need maintenance.

Do I need a central humidifier?

Modern homes require a balanced environment and humidity plays a significant role. Too much humidity will create unwanted mould issues. Very low humidity will affect components like hardwood floors, trim and baseboards etc. A central humidifier properly used will bring balance.

How often should I do duct cleaning?

This depends on many factors. Right after renovations is a must. The ducts are full of debris and dust. In a rural setting, probably every 3 years. It is easy to determine whether duct cleaning is required, by removing a supply and a return register and taking a look.

Can I just use the cheap filters and replace them more often?

Something is cheap for a reason. Cheap filters don’t do much and in my opinion, are  a waste of money.

Leave a Reply

Your email address will not be published. Required fields are marked *