Diesel heaters are very convenient devices perfect for heating truck and boat cabins, living space in caravans, and tents. Their main advantage is low fuel consumption and widespread availability of diesel fuel.
However, users often find diesel heaters noisy, which can be a problem if you want to sleep while the heater is working. This article will help you reduce the operating noise of diesel heaters, so make sure you read it to the end, as it will give you a lot of useful tips.
How Diesel Heaters Work In A Nutshell
Turning The Diesel Heater On
Initial Automatic Checks
When you turn the heater on, the heater control program automatically checks all parts, making sure there are no errors.
Then the blower will ventilate the combustion chamber.
The glow plug will start too so that the diesel mixture can be easily ignited inside the combustion chamber.
The Combustion Process
The diesel fuel is then drawn from the tank by the diesel heater’s metering pump, filtered through the fuel filter, and then flows through the metering pump, which turns it into high-pressure fuel.
The high-pressure fuel oil enters the heaters’ heat plug filter through the fuel line and diffuses through the plug filter.
Simultaneously, the combustion blower works to draw air from outside the vehicle and into the heater’s combustion chamber, creating a spiral of combustion air in the combustion chamber’s turbine.
The combustion air flows by the heater plug filter before it enters the combustion chamber, and it mixes with the diesel fuel diffused through the heater plug filter, forming combustible diesel gas.
The glow plug is already working at that point, and the combustible diesel mixture is instantly ignited, quickly reaching 1000 degrees Celsius.
The sensor inside the heater will detect the flame and will turn off the glow pin.
The fuel pump continuously deploys the fuel to the heater plug strainer, spreading over fuel over it evenly.
Also, the combustion fan sends the retardant air into the combustion chamber.
The combustion air and diesel vapors are mixed, forming an explosive diesel mixture, which burns inside the combustion chamber.
Heater Exchanger Role
A heat exchanger surrounds the outside of the combustion chamber. The heat exchanger has a convex aluminum housing both on the inside and the outside.
The internal bulge allows the heat exchanger’s internal area to expand, which will mean it can absorb more of the combustion heat. The external bulge will allow the exchanger to have a larger mold, which helps transfer the generated heat to the vehicle’s interior.
The combustion heat is absorbed by the bulge inside the heat exchanger, while the exhaust gases created in the combustion process get discharged from the heater, exiting through the exhaust system.
The blower absorbs the cold air from inside the compartment, flowing it through the bulge outside the heater heat exchanger, which heats the air. The blower returns the warmed air to the vehicle’s cabin.
Turning The Diesel Heater Off
When the heater is turned off, the heater control program first shuts off the fuel pump.
As the fuel is no longer coming in, the combustion process inside the chamber will slowly stop. However, as it does, some diesel fuel will be left on the heater plug filter, which wasn’t entirely burned.
Because of this, the heater will start working again to burn off the diesel residue on the heater plug filter, so it can be ready for the next time you turn it on. This will only take two minutes, and after the process is complete, the control program will completely shut down the power to the plug.
However, no matter how precise the control process is, there will always be a slight buildup of the diesel fuel, which can be easily removed by the blower. Therefore, when the plug is turned off, the blower begins to run at high speed, which will blow off any carbon left inside the heater combustion chamber.
And that’s it, now you know how the diesel heater works. It looks like a very simple device, but the processes inside are very sophisticated, which is why it matters to pick a reliable diesel heater that will last a long time.
Which Diesel Heater Parts Produce The Most Noise?
As you can see, diesel heaters have many important parts, but not all of them are responsible for producing noise. Below are the areas that create the most noise during the heating process.
Air Passage Design
When combustible gases burn, they create noise. This is a process that can’t be avoided, it is just how it is.
However, the combustion air passage design can influence the amount of noise output. If the passage has a bending angle in accordance with the fluidic principle, the noise will be reduced. But, this requires extensive technical knowledge by the heater manufacturer. Only a few of the top heater manufacturers are able to design the combustion air passage this way.
Warmda Diesel Heater Combustion Tube Quality
Inside the combustion chamber of the heater, there is a combustion tube. It’s made of stainless steel and is evenly rounded to allow uniform combustion of the diesel fuel. The uniform combustion will reduce the noise produced by the burning process.
However, because the burning temperature inside the heater exceeds 1000 degrees Celsius (1800 degrees Fahrenheit), that can become a problem.
Ordinary stainless steel materials deform when the temperature exceeds 800 degrees Celsius (1450 degrees Fahrenheit), and over time, the deformation of the combustion tube worsens.
That’s one of the reasons why heaters don’t make a lot of noise when they are new, but the output increases over time.
We recommend that the burner cylinder be made of 2520 stainless steel to counter this issue. The wall thickness of the burner cylinder should be 1.2mm. This type of cylinder will be able to withstand high temperatures without deforming.
The noise created by gas combustion is emitted out of the heater with the exhaust gasses. As we know, the sound is transmitted in the form of sound waves, which have a wavelength. Because of this, we should choose spiral exhaust pipes, as their shape can offset some of the combustion noise that passes through the exhaust pipe.
To reduce the amount of combustion noise even further, we can use an exhaust muffler. But, it is extremely important that the muffler is not made of asbestos, as the material is toxic for health and the environment.
The heater motor is not running at the same speed during the operation, which is normal. The control program detects and adjusts the amount of diesel fuel entering the heater, and the motor speed is continuously adjusted accordingly to match the amount of fuel. Also, the amount of combustion air entering the chamber is matched to the amount of diesel fuel entering the heater.
However, uneven combustion air will inevitably result in uneven noise from the heater. Because there is no way to change the motor’s speed at that point, as it depends on the other parts of the process, we need to reduce the combustion noise in a different way, by adding a combustion air filter.
At its heart, the combustion air filter has a sponge. As the air flows through the sponge, it becomes relatively uniform, which reduces the noise of the heater operation.
Things You Can Do During The Diesel Heater Installation To Reduce The Working Noise
Between the heater and the mounting plate, there’s a rubber gasket. Its purpose is to keep the exhaust gases from entering the carriage. But, it also acts as a shock absorber and reduces the noise the heater makes.
However, after a few years of use, this rubber gasket may deteriorate. With age, it will lose its sealing and anti-vibration properties, and you will need to replace it.
Exhaust Pipe Clamps
Another common source of noise is the weak exhaust connection, which allows the exhaust pipe and the heater to resonate. To make sure this doesn’t happen, you will need to use heavy-duty exhaust clamps. These clamps will hold the exhaust pipe firmly in place at the heater combustion exhaust vent, preventing resonance.
Fuel Pump Mounting Bracket
Most heater manufacturers have a rubberized fuel pump mounting bracket that will reduce the fuel pump’s operation noise, so make sure you use it.
Most people install the exhaust muffler the wrong way, putting them at the end of the exhaust pipe. However, this is wrong. If you want maximal muffling, you need to install the exhaust muffler between the two exhaust pipes.
This article gave you a lot of information about the diesel heater operation. Now you have a general understanding of how the device works and which parts generate the most noise. You also know how you can fix the common issues, minimizing the noise output.
However, if something still isn’t clear to you, or you have other questions and ideas, don’t hesitate to contact us. Our customer support team will get back to you within 8 hours.
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