AC Fan setting and mold production - The link

You may or may not be a summer lover but one thing we're sure of; none of you is a mould lover. Unfortunately, with summer comes mould; this is almost a one comes with the other formula if necessary preventions are not taken and healthy HVAC practices are not followed. The primary cause behind the production of mould is the humidity, the level of which goes up in the summer. Although Air Conditioners do help dehumidify the indoor air, you'll be surprised to know that this does not happen on its own and the Thermostat, if not set well, can actually make the Air Conditioner a contributor to the production of mould by not allowing it to dehumidify the air while it cools it off. We'll learn today about that Thermostat setting that goes wrong and leaves homeowners in discomfort.

The complexity of Fan ON-AUTO Setting

What most homeowners do is that they set the AC Fan on ''ON'' instead of ''AUTO''. When the Fan is set on ''ON'', it does not dehumidify the indoor and as a result, the humidity level soars. Professionals suggest maintaining a humidity level between 30%-50% but as the Thermostat is set on ''Auto'', humidity can rise to an extremely uncomfortable level of 70% or more. As a homeowner, you should understand in detail how the ''ON''setting prevents dehumidification. And here's the explanation for that.

How does the ''ON'' setting prevent dehumidification

The cooling cycle that the Air Conditioner follows makes use of the indoor warm air to cool it over the evaporator coil. As the warm air is cooled, the water vapours get collected in a condensation pan and exit through the condensate drain. But this happens when the Fan is set to ''Auto'' and it shuts off automatically after the cooling cycle. This way the water vapours that get collected over the evaporator coil get time to drip in the condensation pan. But hey! Here's what happens in the ''ON'' setting. The Fan setting when set to ''ON'' lets the fan run constantly. This way the evaporated vapours are pulled along the cool air taking all the humidity back to home. So moisture ends up where it started. This is why switching from ''ON'' and ''Auto'' is a really smart thing. 

What else do I do to prevent mould?

- To prevent mould, you need to fix the humidity causing factors. In order for the Air Conditioner to dehumidify the indoor properly, the formula is; the longer it runs, the better it will dehumidify. So check if your AC is the right size. Larger than required sizes trip frequently not allowing proper dehumidification.

- You can consider installing plants, make in time use of exhaust fans and also placing a silica bag somewhere in the indoor can do wonders especially if you have a small area to dehumidify. It will suck the moisture in the air.

- Last but not the least; if your Air Conditioner fails to combat humidity whatsoever, is an old unit or does not help dehumidify for whatever reasons, consider installing a separate whole home dehumidifier.
But before you go, remember, you're supposed to never set your Fan on ''ON'' for more than a day!

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