Explained: Different types of inverter compressor technologies available in refrigerators – Times of India

The compressors are like the heart of the refrigerators as this core component is responsible for circulating refrigerant inside the appliance, just like the heart is responsible for circulating blood all over the human body. Adding an inverter to the compressors will be like adding a ‘brain’ to this ‘heart’. Moreover, inverter technology has modernised home appliances like — ACs and refrigerators by significantly reducing energy consumption and turning them into even more silent appliances. However, these inverters are marketed differently by various brands and to check the legitimacy of each technology, we will inspect the different types of inverter technologies that are available for refrigerators here. This will help users to distinguish between different technologies that are offered by different competitors. Let’s start with understanding the role of compressors in refrigerators.
What role do compressors play in refrigeration?
The primary function of a compressor is to compress refrigerant inside the refrigerator where the refrigerant gas turns into a hot liquid when compressed. The refrigerant is then cooled down as it passes through a cooling condenser and is eventually circulated inside the refrigerator. The refrigerant takes in the heat from the refrigerator as it circulates and expands itself to become a gas that finally reaches back to the compressor which again squeezes it back into a hot liquid and the cycle goes on.
This means that the compressor acts like a pump designed for vapour instead of water. It compresses warm refrigerant gas into a hot liquid and then releases the heat to the environment by pushing it to the coils.
What is a standard compressor?
Earlier, most fridges used to come with a standard compressor that activates when the refrigerator’s temperature exceeds a certain limit. However, these compressors deactivate themselves as the temperature falls below the limit and waits for the next refrigeration cycle. Standard compressors are single-speed compressors that can either stay ‘on’ or ‘off’ and operates at maximum power when activated. It can’t vary the speed depending on the rising temperature and the constant switching of states increases the wear and tear of the appliance along with creating a discerning noise every time the states are switched.
What is an inverter compressor?
As mentioned earlier, adding an inverter to a compressor makes the refrigerator smart. Inverters are added to refrigerator compressors by using brushless direct current or BLDC motors. These motors allow the compressor to run with different levels of intensity or speed depending on the temperature and other environmental conditions. So inverter compressors are variable-speed compressors that use BLDC motors to operate at variable speeds.
Different types of inverter compressors marketed by various brands
Digital Inverter — A variable-speed compressor or inverter compressor is marketed as a digital inverter when it is controlled by a microprocessor using algorithms (software). This technology is used by Samsung where the digital inverter compressor remains “on” most of the time, unlike the standard compressors. However, the digital inverter compressor operates at different speeds based on the situation and requirement. Samsung allows seven adjustable speeds in the digital inverter technology it uses for its refrigerators.
NutriFresh Inverter — A Nutrifresh inverter is also a digital inverter that is marketed by Godrej. Apart from being controlled by microprocessors, this digital inverter has special sensors that offer customised cooling depending upon the type of food inside the refrigerator to keep them fresh for a longer time.
IntelliSense Inverter — This technology is used mostly in Whirlpool inverter refrigerators that are assisted by three sensors for optimum control. For example, one sensor brings the information about internal temperature, the other one estimates the amount of food load present inside the refrigerator and the last one senses the pattern of its usage to deliver precise speed control for the compressor.
Plasma Inverter — Apart from the IntelliSense inverter technology, Whirlpool introduced another improved technology in 2019. Besides the smart sensor-based controls, the plasma inverter technology includes an additional layer of plasma coating on its compressor rod which helps in improving the longevity of the appliance. The company claims that a plasma IntelliSense inverter is designed to last 5 years more than an ordinary digital inverter.
Smart Inverter — LG uses this technology in single-door refrigerators and markets it as the smart inverter technology. Just like digital inverters, smart inverters also use microprocessors for optimum cooling control.
Inverter Linear Compressor — LG further developed the concept of inverter compressor which it uses in its premium fridges. The inverter linear compressor uses a linear arrangement of an electromagnet to compress the refrigerant. The electromagnet attracts the plate to which the piston is fixed. A digital inverter compressor involves 4 friction points whereas a linear inverter compressor uses the electromagnet setup and reduces it to a single point. This provides higher energy efficiency and reduces energy wastage. Apart from improved energy saving, linear inverter compressors keep the food fresher for a longer period amid a wide range of environmental conditions.