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Allergies, Asthma, or Other Sensitivities? How to Use Your Air Conditioner to Control Air Quality Inside Your Home

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While all air conditioners allow you to vary the temperature of the air inside your home, did you know that you can control the air quality as well? For most people, the quality of air would not be much of a concern. If you are not prone to respiratory distress (from a condition such as asthma) or allergies, then the quality of air inside your home is unlikely to affect you in any tangible way. If you do have a sensitive respiratory system or are prone to allergies, you might wish to examine the minimum efficiency reporting value (MERV) of your air conditioning unit's filter and upgrade it if necessary. But what exactly is a MERV and what difference does it make? 

Keeping it Clean

First of all, it doesn't matter what kind of minimum efficiency reporting value your air conditioner has if the filter is dirty. A dirty filter will blow a large amount of dust and other airborne particles into your home. Ensure that the filter is cleaned as per the manufacturer's instructions. If you have an older air conditioner unit and can no longer find the instructions, simply look it up online. It's worthwhile to take the time to find the instructions for your specific unit as the cleaning instructions can vary. Some filters can be cleaned with a garden hose whereas others need more specialist care.


The MERV of your air conditioner is determined by your filter, which is why it's important to keep it clean. A window-based air conditioner filter will have a MERV of between 1 and 4 points, which is the lowest possible section. This keeps out large airborne debris but allows smaller particles to be pumped into your home, which is bad news for those with a sensitive respiratory system or allergies.

A Medium MERV

A split system air conditioner filter generally has a higher MERV rating of between 5 and 8 points. This keeps out plant spores and dust mites, which makes for easier breathing for those who are sensitive to such items. If you are highly sensitive to airborne particles, you might wish to obtain and install an air conditioning filter that offers a rating of between 9 and 12 points. 


Most air conditioning units will allow you to upgrade the filter for one with a higher MERV rating, but even those who are highly sensitive should not go beyond a rating of 12. Any higher than this, and it's the type of air filtration system that is used for hospital surgical theatres and even virus research laboratories. The motor on a household air conditioning unit cannot continually provide air that has been refined to such a high level, as an industrial sized motor is required. Too high a MERV will shorten the life of your air conditioner and some manufacturers may not recommend going beyond a certain MERV. Check with the manufacturer to see if this is the case with your particular unit.

Electricity Usage

Please remember that a higher MERV rating can result in higher electricity usage. Your unit has to work that much harder in order to pass the same amount of air through a denser filter (and the higher the MERV rating, the denser the filter).  

Should you suffer from a sensitive respiratory system and wish to improve the quality of your air inside your home, then it can be worth it to upgrade your air conditioner's filter to one with a higher MERV rating.