Refrigeration - Fouling in the sizing evaporator and condenser

In summary, fouling in a Refrigeration cycle can greatly impact the performance of heat exchangers by increasing resistance to airflow and reducing heat transfer coefficients. It is important to monitor and clean heat exchanger surfaces to maintain system efficiency. When sizing the Evaporator and Condenser, fouling should be acknowledged but does not need to be specifically accounted for. Using a filter can help reduce fouling buildup.
  • #1

I am trying to determine the importantance and difference of fouling in sizing the evaporator and condenser in a Refrigeration cycle?


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  • #2
I got this from the ASHREA Handbook:

Fouling, an accumulation of dust or condensates on heat exchanger
surfaces, reduces heat exchanger performance by increasing
resistance to airflow, interfering with mass transfer, and generally decreasing
heat transfer coefficients. Increased resistance to airflow increases
fan power requirements and may reduce airflow.
Increased pressure drop across the heat exchanger core can indicate
fouling and, with experience, may be used to establish cleaning
schedules. Reduced mass transfer performance (latent effectiveness)
indicates fouling of permeable membranes or desiccant sorption
sites. Heat exchanger surfaces must be kept clean to maximize
system performance.​
2008 ASHRAE Handbook - Heating, Ventilating, and Air-Conditioning Systems and Equipment (I-P Edition).

In terms of sizing the Evaporator and Condenser, fouling doesn't need to be taken into consideration, rather it is more important to know that it is there and will eventually cause degradation in performance.

To reduce fouling you can use a filter.

I hope that helps.

1. What is refrigeration fouling?

Refrigeration fouling refers to the buildup of unwanted substances, such as dirt, dust, and debris, on the surfaces of the evaporator and condenser in a refrigeration system. This can negatively impact the efficiency and performance of the system.

2. How does fouling affect the sizing of the evaporator and condenser?

Fouling can decrease the heat transfer efficiency of the evaporator and condenser, causing them to require larger surface areas to achieve the same cooling capacity. This can lead to increased energy consumption and operating costs.

3. What are some common causes of fouling in refrigeration systems?

Fouling can be caused by various factors, such as inadequate filtration, poor system maintenance, and exposure to environmental pollutants. It can also be caused by the type of refrigerant used and the operating conditions of the system.

4. How can fouling be prevented or minimized?

Regular maintenance and cleaning of the evaporator and condenser can help prevent fouling. This includes changing filters, removing debris, and using appropriate cleaning solutions. Choosing a suitable refrigerant and keeping the system operating within optimal conditions can also help minimize fouling.

5. What are the consequences of ignoring refrigeration fouling?

If left untreated, fouling can lead to reduced cooling capacity, increased energy consumption, and potential system breakdowns. It can also result in higher operating costs and shortened lifespan of the refrigeration system. Therefore, it is important to address fouling promptly to ensure the efficient and reliable operation of the system.

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