Refrigeration - Fouling in the sizing evaporator and condenser

[alexisonsmith]

Hey,

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

Thanks,

Alexisonsmith

 

[droc22]

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.