Select your language

Technical analysis on energy efficiency in HVAC/R systems

eficiencia energética

I thoroughly study the concept of energy efficiency in a cooling system and its importance with climate change.

By Jimy Danelli*

At present the cost of energy has a great relevance, not only for the economy of the companies but for its environmental impact, being the refrigeration and air conditioning systems machines that demand a large amount of energy to reduce the temperature, both of a cold room and also in the environments to be conditioned of offices, schools, homes and businesses. So much so that manufacturers, by obligation, must indicate in their characteristics EER (Energy Efficiency Ratio).

Energy efficiency is defined as PAE=x/l where l is the length of the evaporator, and x is the distance where evaporation is occurring, measured from the inlet and to the point where evaporation ceases.

- Publicidad -

The compressor and its efficiency can be checked with a rule of thumb in which a ratio of compressor power (kW) to delivery volume (m³/min) at rated pressure is used to determine whether the compressor needs to be replaced.

ROE and the COP
As already mentioned, there are nomenclatures that are obtained in the description of the systems; the terms COP (coefficient of performance) and EER (energy efficiency ratio) describe the heating and cooling efficiency of HVAC equipment.

In air conditioning systems, chillers are the machines that are responsible for generating cold for the enclosure. It is important to know the bases of its operation to be able to apply and understand how cold is generated and what elements intervene in evaporation.

Carnot's theorem states that the performance of a thermal machine is always less than or equal to that of a reversible thermal machine operating between the same temperatures. Assuming an ideal gas, the performance of a thermal machine is:
yield = 1 – Tf/Tc
Tf = cold source temperature
Tc = hot focus temperature

The ideal Carnot cycle is reversible and with it the Carnot refrigerator is obtained, which is the one used in the cold production units.

A refrigeration or air conditioning system will have a heat absorption capacity, this according to the calculated capacity and within certain parameters.

- Publicidad -

The main parameter that is taken as a reference is the evaporation temperature, with it we can have an idea of the working temperatures of the system, especially in refrigeration systems where it is not only an obligatory reference, but it is already more than a norm when it comes to knowing how the equipment works.

It is considered that in a medium or low temperature system the difference between the evaporation temperature and the chamber temperature ranges between 5K and 8K, hence the pressures of some systems are vacuum pressures, such as some refrigerators (refrigerators) of R134a, where at an evaporation temperature of -30 ° C the pressures are vacuum (-2.46 psi).

So when we have a system evaporating at -25 ° C we can say that the chamber temperature is at least -20 ° C and if we are working with R404A the pressure would be 21.20 Psi.

All these are parameters that could be even diagnostic, in the subject of air conditioning (air conditioning) is different, because evaporation is from 4 ° C to 7 ° C because the thermal loads to be lowered are high, hence lower evaporation levels are not required.

Evaporation is obviously the consequence of the heat absorption of the system, hence the importance of temperature because it is a direct reference of the operation.

For us refrigeration and air conditioning technicians it is important that the client has a system working under the parameters of energy consumption within the design values, it is possible that the equipment is working very well, however in terms of its energy efficiency it is outside the design values.


For this reason it is very important to execute a rigorous maintenance that allows the greatest possible heat absorption in the evaporator in the shortest time and a heat dissipation in the condenser that allows the efficient use of energy, otherwise, the electricity bill may be reflected with increases due to lack of maintenance, In addition to degrading the operation of the compressor, since it will continue to operate until reaching the desired temperatures and under condensing pressures well above those of the design.

Maintenance plans
That is why both refrigeration systems and air conditioning systems are designed maintenance plans that allow maintaining the values of energy consumption in the design parameters which will maintain the desired operating costs, in addition to minimizing the environmental impact or what we now call the carbon footprint, By having the equipment working with a minimum consumption, this being more friendly and sustainable for the environment.

All refrigeration professionals have a great responsibility to inform customers and end users of the different systems, the operating conditions of the equipment and that not being in constant maintenance generates higher economic costs and a considerable environmental impact.

When a system consumes more energy, in the Thermoelectric Generating Plants more fuel must be burned, this in turn will generate greater CO2 emissions and contribute to climate change, which is a consequence of global warming that is being generated by CO2 emissions, which causes the greenhouse effect.

Indeed, global warming causes the earth to increase its temperature level very rapidly due to the increase in production and demand for energy that is based on fossil fuels.

Consequently, climate change could put at risk the survival of animals and plants on our planet, it may even affect the survival of man.

Then, the increase in temperature causes the ice masses to melt, which increases the sea level, then this can produce floods that threaten the coasts and some coastlines could be at risk of disappearing.

Another consequence of climate change is that meteorological phenomena such as hurricanes, severe droughts, fires that destroy plants and animals occur. These are man's subsistence resources, which if run out or scarce could cause serious danger to human subsistence.

* Jimy Danelli is a maintenance consultant in air conditioning and refrigeration. You can write to the email: [email protected]

Duván Chaverra Agudelo
Duván Chaverra AgudeloEmail: [email protected]
Jefe Editorial de las revistas AVI Latinoamérica, ACR Latinoamérica, Ventas de Seguridad, Zona de Pinturas, Aftermarket Internation, Gerencia de Edificios, TV y Video, y Director Académico en Latin Press, Inc,.
Comunicador Social y Periodista con experiencia de más de 18 años en medios de comunicación. Apasionado por la tecnología y por esta industria.

No comments

• If you're already registered, please log in first. Your email will not be published.

Leave your comment

In reply to Some User
Register for the Building Automation Webinar: Keys to Understanding Modbus and BACnet

Register for the Building Automation Webinar: Keys to Understanding Modbus and BACnet

International.  On March 27, 2025, ACR Latin America will offer a webinar focused on building automation protocols, with an emphasis on understanding Modbus and BACnet.

Scientists develop the first elastocaloric air conditioner on a commercial scale

Scientists develop the first elastocaloric air conditioner on a commercial scale

International. Researchers at the Hong Kong University of Science and Technology (HKUST) have developed the first elastocaloric air conditioning system with cooling capacity on a commercial scale.

Daikin recognized among the

Daikin recognized among the "Clarivate Top 100 Global Innovators 2025"

International. Daikin Industries has been selected as one of the Clarivate Top 100 Global Innovators 2025, a distinction awarded by Clarivate, a global information services company based in London,...

Condensation Control: A Challenge for HVAC System Efficiency

Condensation Control: A Challenge for HVAC System Efficiency

International. Condensation damp represents a major challenge in the air conditioning of buildings, affecting energy efficiency, indoor air quality and occupant comfort.

Honeywell to Convert Its Refrigerant Business to a Standalone Company: Solstice Advanced Materials

Honeywell to Convert Its Refrigerant Business to a Standalone Company: Solstice Advanced Materials

United States. Honeywell announced that its refrigerant business will be renamed Solstice Advanced Materials as part of its plan to become an independent, publicly traded company in the U.S.

SODECA revolutionizes fire safety with a simulation of its pressurization system

SODECA revolutionizes fire safety with a simulation of its pressurization system

International. SODECA's BOXPDS has surprised with an innovative live demonstration of its evacuation route pressurization system. The system creates a barrier against smoke in just three seconds.

Resideo will invest more than 4.9 million dollars in Aguascalientes to install corporate office

Resideo will invest more than 4.9 million dollars in Aguascalientes to install corporate office

Mexico. The U.S. company Resideo announced an investment of more than 4.9 million dollars (99 million Mexican pesos) to establish a corporate office in Aguascalientes, from where it will provide...

Webinar: Building Automation Protocol: Understanding Modbus and BACnet

Webinar: Building Automation Protocol: Understanding Modbus and BACnet

Topic: Building Automation Protocol Overview: Understanding Modbus and BACnet By: Camilo Olvera, Sales Manager for Mexico Armstrong Fluid Technology Alejandro Hernández, Distribution Manager –...

Six Marketing Trends for HVAC Companies in 2025

Six Marketing Trends for HVAC Companies in 2025

The HVAC industry is in a stage of limitless transformation, driven by technology, sustainability and the evolution of the expectations of all consumers. By Andrea Álvarez*

Mabe to invest $668 million in Mexico through 2027, despite tariffs

Mabe to invest $668 million in Mexico through 2027, despite tariffs

Mexico. The multinational Mabe announced an investment of 668 million dollars in Mexico between 2025 and 2027, regardless of the tariffs imposed by the United States.

Free Subscription
Remember Me
SUBSCRIBE TO OUR NEWSLETTER
DO YOU NEED A SERVICE OR PRODUCT QUOTE?
LASTEST INTERVIEWS
SITE SPONSORS










LASTEST NEWSLETTER
Ultimo Info-Boletin