Oxygen Concentrator-Types, Uses, Workings, Maintenance, Price, and Contact

A medical oxygen concentrator is a part of an oxygen delivery system that is used to extract and supply oxygen gas directly from the environment.  The medical concentrator is a type of concentrator that supplies oxygen with a purity of at least 90% for any flow rate. If it fails to meet this criterion, then it can not be considered as a medical-grade concentrator. The other kind of concentrator is known as the portable oxygen concentrator. We will talk about the differences between these products in this topic. Besides that, we will also talk about the features, applications, maintenance, price, and contact for you to purchase some of the best concentrators present in the Nepalese market. 

Medical Oxygen Concentrator Vs Medical Oxygen Cylinder

Some of the differences between oxygen concentrators and cylinders are stated below.

Oxygen Concentrator Oxygen Cylinder
Needs ac supply for operation Does not need any power supply
Weight ranges from about 5 to 50 kg Weight ranges up to 50 kg or more
It has got lower oxygen purity (about 94%) and oxygen pressure. Also, the flow rate is also low compared to an oxygen cylinder. It has got higher oxygen purity (about 99%) and oxygen pressure. Also, the flow rate is high.
Works for 24 hrs. No need for refilling Needs to refill the cylinder once it is empty.
Has got a wheel in it. Thus, it easier to transport from one room to another Does not have a wheel in it. Thus, it is not easy for transportation (Steel-type)

If you need oxygen for a few days, you may buy only an oxygen cylinder. Else buying an oxygen concentrator will be more economical for you.

If you need to use an oxygen concentrator you will have to buy an oxygen cylinder for a backup. You may need the oxygen cylinder in case of the 

  • power failure in your house
  • malfunctioning of the concentrator

Since the purity of the oxygen cylinder is more than that of the concentrator, you need to increase the flow rate of the concentrator to obtain the same result. For example, a patient needs an oxygen flow rate of 1 liter/min while using the oxygen cylinder. Then, for the oxygen concentrator, the flow rate should be slightly above 1 liter/min.

Medical Oxygen Concentrator Vs Portable Oxygen Concentrator

A portable oxygen concentrator is different than a medical oxygen concentrator in a number of ways.

Medical Oxygen Concentrator

Portable Oxygen Concentrator

Normally weighs from 20- 24 kg

Normally weighs around 6 kg


Quite expensive

Has got wheels at the base. Thus you can move it easily from one room to another

Can even be carried on like a bag while going outside

Flow rate can range up to 10 liters/min (based on the models)

Flow rate can range up to 7 liters/min (based on models)

Single or dual patients (based on models)

For single patient

Operates on AC 220 Volt with no battery backup

Operates on AC 220V and may have battery backup

Delivers around 90% – 96% oxygen purity

Delivers around 38% -90% oxygen purity

Applications of Portable Oxygen Concentrator

  • While going outside for shopping, traveling, etc.
  • Mental worker and student recover energy
  • Pregnant women
  • Oxygen cocktail making

(Note:- It is not designed to use for medical purposes.) 

Who needs an Oxygen Concentrator?

It is mainly needed for COPD and hypoxia patients.

Handling of the Oxygen Concentrator

  • The oxygen concentrator produces a high amount of oxygen. Oxygen helps in rapid burning. So, you should not place the machine near the fire/ kitchen. Similarly, smoking, use of petroleum products, lubricants, grease, etc, should not be allowed near the machine.
  • Operate the machine in an open space. Maintain a gap of at least 2 feet between the machine and the wall of the room.
  • Place the machine on the floor. Do not place it on top of the table, bed, etc. Else, the machine might fall due to the vibration created by the compressor of the machine. 
  • Keep the machine in a clean environment. This will increase the life span of the machine.
  • Clean the humidifier bottle with clean water. I recommend you not to use tap or filtered water in the bottle. Instead of that, you can buy distilled water from the market. 
  • In the case of any problem with the machine, consult with the service engineer. Do not open the machine on your own.

Components of the Oxygen Concentrator

  • Compressor
  • Sieve Bed (Zeolite Tower)
  • Filters
  • Tubes
  • Four-Way Directional Valve (Solenoid Valve)
  • Cooling Fans
  • Pressure Sensor and Pressure Regulator
  • Accumulator Tank (Oxygen Tank)
  • Flow Meter (Rotameter)

Working Mechanism 

Block Diagram of Oxygen Concentrator

First of all, air from the atmosphere goes inside the compressor through the filters. The piston inside the compressor will pressurize the incoming air and sends it to the four-way directional valve. This pressurized air will release heat. So to cool it down, a cooling fan is used. Through the valve pressurized air goes to one of the sieve beds. The sieve bed consists of zeolite powder which allows oxygen to pass through it. The pressure in the sieve bed is analyzed by the circuit board. When certain pressure is reached, the circuit board allows four-way directional valves (solenoid valve) to change the direction of airflow. Now the air goes to the other sieve bed for filtration. While this process is going on, the other sieve bed will depressurize and gases such as nitrogen and water vapor will release back to the atmosphere. You need two sieve beds so that they can supply oxygen continuously.

Filtered dry oxygen will then accumulate in the accumulator tank. It consists of a dial pressure gauze and a pressure sensor. The pressure sensor is used for safety purposes i.e. when the oxygen reservoir becomes full then the air compressor stops working. From the accumulator tank, some amount of oxygen goes through the circuit board to check its purity. A major portion of the oxygen goes through the rotameter. It helps to regulate the amount of oxygen output. Then it comes out of the machine at a controlled rate through a humidifier.

Reasons for the vibration of the oxygen concentrator

You need to be careful about the noise that your concentrator makes. This is because it will give you an idea about the current situation of your machine.  Some of the reasons could be because of the:

  • Age of your machine
  • Low voltage from the power supply. The compressor will have difficulty operating.
  • Air leakage from the pipes or the solenoid valves.

Maintenance of Oxygen Concentrator

(Factors affecting the output of the oxygen concentrator)

  • Check the output of the concentrator with the help of an oxygen analyzer or you can also use the pulse oximeter.

1. Machine does not operate

If the machine does not turn on, then it can be because of the malfunctioning of the power cord, switch, fuse, or mainboard. If such a problem occurs, then make sure to replace the malfunctioned part.

Generally, you will find a 3-5 A fuse. Similarly, the switch will be of 4- pins. You can check the continuity of the switch. But, I recommend you to cross-check it with a new one, instead of fully trusting the multimeter.

2. Filters

You will find three types of air filters in the oxygen concentrator. The outer dust filter filters the dust particles. It also protects the inner HEPA filter. You can clean this filter with soap and water. 

You need to replace the HEPA filter periodically (at least twice a year).

There is also a bacterial filter. 

3. Zeolite Tower (Sieve Bed)

Sieve Bed / Zeolite Tower, Oxygen Concentrator
Image Source:-

A pair of zeolite towers lies within the concentrator. After continuous use of the concentrator, the effectiveness of the tower keeps on decreasing. Lumps of the zeolite may be formed within the tower. Besides that, there can be leakage at the outer layer of the zeolite tower. So, you to cross-check the zeolite tower in that case.

The orifices of the zeolite should not be exposed to the environment. Else the dust and dirt can contaminate the zeolite powder. Besides that, atmospheric moisture can lead to the formation of a cluster of powder. 

4. Tubing

There are several flexible tubing inside the concentrator.  Due to the high pressure of air, friction developed within the machine, the tubes may rupture. Thus, in that case, there might be air leakage. So, you need to replace the tubes in that case.

5. Compressor

The compressor may not be working properly. This can be because of 4 main reasons. The capacitor, washer, piston, or the bearing of the compressor may have been damaged. If possible, you can replace these components separately. Else, you need to replace it with a new one.

Compressor, Oxygen Concentrator
The compressor of the Oxygen Concentrator
Washer of the Compressor, Oxygen Concentrator
Washer of the Compressor

The compressor operates at 240 VAC. Similarly, the capacitors might operate at 6 µF, 10 µF, 15 µF, etc. You can directly give an AC supply to the compressor and check it. In the case of the capacitor, I suggest you cross-check it with a new one. 


6. Solenoid Valve

Solenoid Valve, Oxygen Concentrator
Solenoid Valve

The solenoid valve operates on a set of zeolite towers. When a certain pressure in the oxygen tank is reached, the valve makes a click sound. After that, the path of the oxygen changes in another direction. After the click sound, the unfiltered gas (eg. nitrogen), returns from the zeolite tower to the valve. Then it goes to the environment.  You can hear a different sound when the unnecessary gases return to the environment.

If the valve does not make a click sound, then you can manually supply 12 VDC to the valve and check it. Similarly, if the output from the compressor does not meet the required air pressure, then the valve may not operate even after making a click sound. So, you may need to cross-check both the compressor and the solenoid valve.

7. Fan

The fan is needed for the cooling of the compressed air released by the compressor. 

If the fan stops working, then the temperature of the pipes will rise up. This will cause the burn and breakdown of the pipes. After that, the atmospheric air will directly enter the zeolite tower. So, it will soon be contaminated and will expire. 

If the temperature of the concentrator increases beyond the normal level, then the problem might be with the fan. In such a case, you need to replace the fan with a new one. 

8. Flowmeter

The problem may arise in the flowmeter (rotameter). In such a case, there will be a decrease in the flow rate from the machine. Also, the oxygen purity may decrease. So, you need to take extra care with the flowmeter. 

Sometimes the float will get stuck at the base of the flowmeter. In such a case, you can shake the flowmeter by removing it from the machine. You may even use a higher gust of air to force it to move. If the knob or the glass layer is damaged or broken, then you need to replace the flowmeter with a new one.

Even for the same capacity of the rotameter, the size and thickness can differ from one company to another. So, as far as possible make use of the rotameter of the same model. 

Zeolite( Al2SiO5)

Zeolite, Zeolite Powder 13X
Image Source:-

Zeolite tower consists of zeolite. It is a naturally occurring, crystalline, microporous compound. Nowadays, these compounds are also synthesized to form a powder.

1. Working Mechanism

It is based on the process of adsorption. When gas or liquid passes through the zeolite surface, smaller-sized molecules pass through the surface while larger-sized molecules are adsorbed by the surface.

2. Zeolite for Adsorption 

Zeolite is the major source of filtration in the oxygen concentrator. The most widely used zeolite for the oxygen concentrator is zeolite 13X. You will find zeolite inside two of the zeolite towers. 

When compressed air is passed through zeolite powder, oxygen passes through it. Other gasses such as nitrogen and argon having higher molecular size get adsorbed by the power.

Life Span

Generally, the life span of zeolite powder is above 2 years (in the case of an oxygen concentrator). However, if you do not handle the sieve bed properly, then it can expire within few days. 

Best Oxygen Concentrator in Nepal

Based on the price, quality, features, accessibility, and after-sales service, here are a few of the best medical oxygen concentrators found in Kathmandu, Nepal. Every company stated below will give you the facility of maintenance, even after the warranty period is overAt the end of this topic, I will be providing you with the contact details.

1. Nidek

This USA-based concentrator is one of the oldest concentrators found in Nepal.  The machine is simple and reliable. According to the customers, the life span of the machine is really high in comparison to that of other companies. 

The supplier will give you at least 1 year of warranty.  

The major problem with this machine is that it has only got a clock display which shows the total number of running hours. Besides that, the price of this machine is quite high. 

2.  Oxyflow 5

This Oxyflow 5 model of an oxygen concentrator is similar to that of the Nidek Company.

The major advantage of the Oxyflow 5 concentrator over Nidek is its price. 

3. Instrumenta

This Spanish-based Chinese product is one of the best concentrators that you can find in the market. Unlike Oxyflow or Nidek, it provides you with a digital display. It has got an inbuilt oxygen analyzer. So, you can check the output of the machine on your own.  It has also got the feature of the nebulizer. Thus, you do not need to buy another nebulizer machine. Similarly, it provides you with the option of a timer. 

The price is lower than those stated above. The only disadvantage of Instrumenta is that the life span may not be as high as those explained above. 

4. Olive

If you are looking for a good medical concentrator at a lower price, then Olive is your choice. 

It is a Chinese-based product. The machine is simple and easy to use. Unlike Instrumenta, it does not have an extra feature. However, the company will provide you with at least one year of warranty. 

Contact Details

The contact details of the products stated above are given in the table shown below. 


Authorized Dealer




Bikash Surgical Concern Pvt. Ltd.

Tripureswor, Kathmandu


Oxyflow 5

Oxymed Tradelink

Tripureswor, Kathmandu

+977 985-1160924


Bikash Surgical Concern Pvt. Ltd.

Tripureswor, Kathmandu



Global Medilink

Lazimpat, Kathmandu

+977 9851066645

If you need to get the oxygen concentrator for rental purposes within Kathmandu Valley, then you can contact Oxymed Tradelink. The detail is given in the above table. 

Price of Oxygen Concentrator in Nepal

Before you buy an oxygen concentrator, you need to consider few things. 

  • Manufacturing Country:- In Nepal the cheapest products are from China. If you are buying American or European products, then the price can be even greater. 
  • Features:- If the product has got extra features of the nebulizer or the oxygen analyzer that shows the current level of oxygen purity, the price will be higher. 
  • Size:- The cost of 10 liters/min concentrator is higher than that of the 5 liters/min oxygen concentrator.
  • Transportation:- If the delivery is to be made, away from the Kathmandu Valley, the price can increase.

If you are planning to buy the concentrator manufactured in China, then the normal price for 5 liters/min oxygen concentrator can range between Rs 50,000 to Rs 70,000. However, if you are planning to purchase European or American products, then the price can even cross 1 lakh


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