Excessive Blower Noise

Bad bearings, excessive velocity in ducts, loose hardware in supply fan. Question : did you physically look and ck it out?

You are comparing two Suzuki cars here, does this mean you think the noise is bad in all of the models of that type or just one example?

In other words do you own those 2 individual cars or are you involved in the manufacture of them?

I am not telling that noise is more in suzuki models.

Just an example.... X is better than Y....

That's all,,,

I want the root causes of the issue, if there is excessive blower/fan noise...

That's all

What I meant was that if it is just one car that has more noise, it is more likely to be failure of a component whereas if the noise is more over the entire range of that model, it is more likely to be design of the ducts and parts.

Reasons why design could be the noise is:

*fan motor in thin tin ware instead of solid mount

*fan motor close to the opening of duct

*ducts are loosely stuck together causing rattle

*cheap fan is unbalanced

The list can be as long as you like.

Hope this helps.

You bought a cheap blower from a local manufacturer who during fabrication did not do the dynamic balancing test prior supply.

As Case and Shogun mentioned, it could be several things.

Is the vehicle New or Old?

Did the noise start recently or has it always been there?

Chances are if it's new, bring it in to have it looked at. If they say there is nothing wrong then it is a design problem associated with the manufacturer. Any of the mentioned areas above could be the culprit.

If it's older and just started making noise it could be several issues as stated.

Worn or faulty bearings or mounts.

Dust or gunk built up on the blades and causing an imbalance.

Duct work loosened up over time and causing vibrations through velocity of air or blades striking the housing itself.

Or it could be as simple as leaves or FOD got past your screens and is now hitting the blades. Your best bet would be to remove the fan and inspect, repair, or replace.

Could also be either an acoustic or mechanical resonance of the ducting. The fan itself is usually pretty well buried. It is the duct work or the dashboard that transmits the noise of the fan. If the natural frequency of the dash or ductwork is equal (or close to) to the frequency of the fan speed or fan blade passing frequency then the noise may be amplified.

The first job is to find out what the freqency of the noise is. Fan speed? or blade passing frequency (number of blades times fan speed)?

I have an apple and an orange why don't they taste the same?

I'm getting confused? Are you talking about a blower/fan in HVAC system

or cars?

I am talking about noise in Car HVAC system. New car. One of my friend working in Car manufacturing company in Chennai.

In IQS survey, the common complaint from customer for their model is Excessive noise from AC.

Sorry, I then opt out.

If you do research and find that at x-ambient temperature you need x-number of air changes per hour at x-temperature to produce; fast cool down, maintain a comfortable environment.

You can get the volume of air by - using a high speed high pressure blower through small duct work, or you can use a slower, low pressure blower through larger duct work to achieve the same air changes per hour.

High pressure blower more noise through the entire system - Low pressure blower less noise.

Duct material, vent design can be engineered to lower the noise, but it is mostly the speed you move the air through the system that determines the noise.