Duct Debris Even with air filters, debris can still make its way into the ducts. This can cause rattling, buzzing, or flapping noises as the air moves the debris around the ducts.
Well, SOMETIMES, when folks are ``hearing a sound a little like small critters in my AC vent'', it actually IS a small critter in the AC vent! But more likely, it's the sound being made by the fan blade(s) hitting something that has (somehow) become lodged in your AC vent.
Dirty/Clogged/Old Filter
A clogged filter can cause a high-pitched whistling, loud thumping, or buzzing sound. It can also cause the AC to cycle on and off more frequently. If the cause is a bad filter, replacing it is simple and should result in quieter air vents.
What do mice sound like in vents? When mice are in your vents, you'll hear scratching, crawling, or scurrying on metal in the walls, ceilings, or floors where your ductwork is.
Mice and Other Rodents
But on occasion you may be dealing with squirrels or even rats. There are a number of ways they may have gotten into the ductwork. But they started their journey to the ducts by entering the house first. Once in the house they may have entered the air ducts via the HVAC unit in the basement.
Possible Causes of Ductwork Noise
The most common reasons to hear noise in your HVAC ducts include: Air Pressure: A buildup of pressure can cause rumbling sounds. It can also cause the metal to expand and contract.
Switch off your central heating and cooling system and let the grates reach room temperature. Unscrew and remove the grates that cover your heat vents. For each vent, bait a snap trap with the fragrances of fetching foods, such as raisins, dates, cheese, chocolate or peanut butter.
One of the more unmistakable signs of mice is scratching noises. Mice use their sharp claws to climb surfaces and create nests within walls or other hidden areas. Additionally, gnawing sounds are prevalent as mice chew on various materials like wood, plastic, and even electrical wiring to keep their teeth sharp.
You'll have to turn off your HVAC system and remove all the vent covers. You'll need to load a trap for each vent. Most do-it-yourself-ers use snap traps baited with peanut butter, meat, or cheese. Place the trap just inside the vent and wait.
The sound is transmitted in mainly two ways, some is conducted through the metal of the duct and some is reflected around the inside of the duct until it reaches you. You can reduce both a little, but remember that: You're breathing the air that comes through. You don't want to use materials like fiberglass.
Experts advise having your air ducts cleaned every 2 to 3 years to prevent many maintenance and health problems before they start. However, homes with pets or children with allergies should have their air ducts professionally cleaned more frequently than the recommended average.
There may be a loose part inside of the air compressor knocking around and causing a clicking sound. It's also possible that clicking can originate from the electrical control, relay, or capacitor. All of these are dangerous if they're allowed to continue without being addressed.
There is a sound like someone is walking in my attic – are there unfamiliar sounds emanating from your attic? You are right to be concerned, as scratching and similar noises may indicate rodents or other wildlife taking up residence in your loft.
A gentle humming or clicking is normal, but loud rattling, banging, buzzing, or whistling means you may have a problem requiring professional help. Some factors that cause excessively noisy ducts include dents or damage, loose metal parts, dirty or blocked vents, and closed dampers.
As mice travel through a home's ductwork, they're likely to make noises. Scratching, squeaking, and even gnawing can be heard when these rodents are occupying heating ducts.
If mice are in your walls, you may be able to hear them. In fact, many homeowners hear mice scurrying and squeaking in their walls before they even see one. You may hear mice scurrying around inside your walls and ceiling.
Animals like squirrels, raccoons, and rodents can find their way into your house and into the ductwork. They can even make a new home in the ducts, which becomes a serious problem for your home. If you think you hear scratching coming from your ductwork, it's incredibly important to call professionals right away.
While air duct cleaning can reduce the attractants for mice, it may not completely eliminate a mouse infestation. Mice use air ducts as shelter and navigation routes, and the debris and contaminants in the ducts can serve as a food source.
Mice can live without water for months and without food for 1-2 weeks, but with access to both, they can live up to two years. And due to their constant reproduction, they can live in your walls indefinitely if measures aren't taken to remove them.
Remove AC vents with a screwdriver and place the mouse trap with either peanut butter or whatever little piece of food you don't mind leaving up there. Use a flashlight to look for mouse or rat droppings. If you see a prevalence of them at a specific duct, leave more traps in that area.
You can generally identify a blocked air duct by a distinct drop in heating and cooling efficiency, increased energy costs, and occasionally a musty, dusty smell throughout the home. The blockage usually comes over time, by a buildup of dust and debris that just accumulates until it begins choking the system.