The issue in the attic is that at 48 degrees f.
Very loud noise in attic high humidity.
They may be chewing to improve passageways or just for fun.
In addition to bees ailion says raccoons squirrels and birds have been known to get into attics and cause noises of course mice and rats can do the same.
This is because moist air is less dense than dry air water vapor weighs less than air.
Likely culprits are rats mice grey squirrels and flying squirrels.
Grinding noise in the attic.
Grinding noises are likely to be made by some type of rodent.
The attic fan tends to makes a humming noise when it has a few blades and is running at a high speed setting.
Dry air absorbs far more acoustical energy than does moist air.
You are approaching the 43 deg dew point and some colder surfaces like windows you will get condensation there.
With our recent dry cold spell with sun throughout the day the levels would drop to the 50 s.
In order to get rid of the hum you need to either operate the fan at a low speed or replace the fan with a new one that has more blades.
The high frequency crack has been attenuated more rapidly than the low frequency portion of the noise.
The electrical contractor in the equipment can also make a chattering sound which can damage other components including the compressor if allowed to continue.
An attic that stays overly humid for days or weeks on end can.
That s just the properties of moist air.
The difference in the two spaces is the dry bulb temperature.
Grinding noises are made as rodents chew woodwork.
If your concern is the loud noise dehumidifiers emit this model has a near quiet operation of around 46db.
Fan noise is rated by sones it is the unit of measurement for evaluating how loud a bathroom fan is.
The lower the rating the quieter the unit.
Placing this lg dehumidifier in the attic can greatly improve the high humidity problem without too many interferences.
This is a classic squirrel in the attic noise.
Then with the heat on overnight the humidity level would rise back to the high 70 s.
If you raise the attic temperature the rh in both places would be the same.
The attenuation of sound in air is affected by the relative humidity.
Another cause could be twigs or leaves that have clogged your system.
You simply set the desired humidity level turn on the unit and leave it running.
Snarling noise in the attic.
A rattling noise can mean that your air conditioner is starting to deteriorate and some of its parts are loosening.
You might also install a humidistat that automatically turns your attic fan on to vent out humidity once the level exceeds 70 percent.