> "house fan" for 15 minutes or so every hour at night just to circulate the air in the house,
Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles.
If you run the fan you will then evaporate into the air circulating some of the moisture just removed.
On the other hand, if you don't evaporate water off the coil then it stays wet all the time and grows mold quickly. This is very bad for indoor air quality.
For this reason I intentionally run the fan after a dehumidification cycle. Yes a small amount of humidity goes back in the air, but it's a small price to pay for non-toxic air!
You should probably have your AC unit professionally cleaned and inspected.
As the owner of a whole house fan + evaporative cooler, and someone who lives in a city where hundreds of thousands of people own and operate them, I invite Mr. Kaufman to visit Albuquerque, to watch them in everyday operation, where we've been swamping it up for over 50 years. It's a bit bizarre to read about it as if it's a brand new theory.
Let me clear up a few misconceptions:
You put the fan on the inlet next to the "pad" where the water soaks in (nowadays usually located at a central point on the roof). This works a lot better than a single outlet point for a number of reasons, not least of which the source of air can be made to have reduced dust. (Imagine a leaf blower or old diesel next to a window on a structure with negative pressure).
There are never circumstances where a whole-house fan is made less effective with humidification. It may be no more effective, but for those 100% humid nights where it's cool enough to cool down the house, the swamp still runs. In humid environments, it may warm up the house at night (due to temperatures, not humidity), which is why swamps don't get used in most places.
> The startup's AC units suck moisture out of the air for more efficient cooling.
As someone who lives in the Gulf Coast area, any amount of moisture sucked out of the air is welcome. Take it all! There's an infinite amount of humidity around here. :-)
It's not a fixed amount of condensation because the air around the AC only has so much humidity. It quickly condenses just a little bit of water and then shuts off before the humidity in the rest of the house can redistribute to replace the now dry air. By running for longer it allows the water in the rest of the house to actually make it to the compressor.
If you have the option, a "circ" or timed mode (e.g., 10 minutes/hour) is better than "on" when using air conditioning, as the fan will blow condensed water back off the coil, raising the humidity you just paid to reduce.
It also makes the environment itself uncomfortable in many cases - excessively drying the air, or causing weird moisture/condensation issues (as it won’t fully cycle the air in the house before stopping).
Essentially, you want your HVAC system to run for long enough it’s a gradual transition in temperatures inside and the equipment can run for awhile each time it needs to run to avoid the start/stop problems and let it ‘settle in’.
AC's tend to build up a lot of mold which grows in the condensation and blows it around. People with sinus and allergy issues get stuffy and inflamed. This is why I avoid using the AC and prefer a fan along with opening a window.
We run a humidifier in the winter (Eastern US) because of dry winter air made even worse by the heating process, so this would be a benefit if there is some air circulation to move that moisture throughout the house.
From my previous research on whole-house fans, they are a wonderful device to have so long as you live in a place where the nights are cool, and most importantly, low-humidity. Unfortunately where I live and it’s 80+% RH at night, a whole-house fan would just give me mold.
I was responding to the point about using AC all year to remove humidity. The thermodynamics works like this: The air inside your house is more humid than the air outside; warm air at the same pressure holds more moisture than cold air. When you extract the warm air from the house the heat exchanger cools it down, therefore reducing its moisture carrying capacity and causing condensate to form which you can remove. The heat is transferred to the incoming cold air via the heat exchanger, the warmed up incoming air now has a much greater water carrying capacity even if it was already humid outside so it absorbs humidity from your house, when this air is extracted again the cycle repeats. Passive houses have very low humidity inside because of this.
Keep in mind that (courtesy of the (aeronautical) engineer buddy o' mine) one of the, if not the primary, costs of air conditioning is condensing water out of the air in even moderate humidity.
If you open your house to the outside at night when it is cool enough, you may be allowing moisture into the house which will cost you more during the day when the AC is running.
Moist air from cooking increases the humidity in the house. The walls of the house are cold, the moisture condenses on the cold walls keeping them damp for the entire winter.
It runs for a longer time; the dehumidifying function of an air conditioner (the original use, thus the name) is a function of airflow x time, and airflow doesn't change much.
Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles.
If you run the fan you will then evaporate into the air circulating some of the moisture just removed.
reply