The air flow from the furnace was making interesting noises this morning - perhaps it was as it was travelling through the ducts. I went to the practical to find out what the sound might be and what might cause it - I checked out an HVAC site.
"If your furnace is whistling, one possible cause is that there may be gaps in the duct. You should try to hear exactly where the whistle is coming from. Often, it will be from a small hole near the connecting point between the duct and the furnace close to the blower.
Especially if the whistling has started recently, you may have a clogged filter, causing the fan to suck air from anywhere it can. Even tiny holes or spaces will generate a whistle if any significant air is being sucked through them. To test out this possibility, pull the filter out and see if the whistling stops.
If your filter is so caked with dirt that it is clogged and stopping the air flow, you will be better off taking the filter out (while arranging to purchase a new one). This is better not just to reduce the noise, but also to reduce the wear and tear on your fan motor.
Another possible cause for whistling would be that the ducts are too small. The furnace may need greater air flow, and thus larger ducts."
But would I call the sound whistling? I don't think so. Another site on air conditioning said: "If unusual noises are coming from the air registers (the vents where the conditioned air is blown into a room), ductwork should be inspected. Loose or ill-fitting ducts, as well as debris in the ductwork, may reverberate or echo sounds through the registers into living spaces."
I happened upon a website that creates sounds with a noise generator. They say that "the sound of wind is considered one of the most relaxing sounds in existence. This sound alone eases away stress and makes everything outside look more calm and quiet. The sound of wind is great for helping one to fall asleep and for covering background noises. Wind noise is a natural source of white noise. "
I heard their howling wind - and it isn't relaxing. Perhaps I should have tried desert wind, meadow land or palm garden.
You can listen to the wind at https://mynoise.net/NoiseMachines/windNoiseGenerator.php. There are these types: wheat fields, autumn wind, stormy weather, home alone, deserted barn, trade winds and surprise! At the home page there's Irish Coast, Rain on a tent, Japanese garden, 88 keys, twin black lodges, gregorian chant, waterfall and cafe restaurant. That last one is likely what we would be interested in right now.
After that my research found physics and wave properties. I am still wondering what the names are for different sounds.
Today's leaves are from the Versicolour Japanese Maple in the back garden.
