Congestive Heart Failure and Wet Lungs

Is it common in congestive heart failure (CHF) to have just one lung accumulate liquid?   My elderly 85 year old father has CHF and I noticed that his right lung sounds "wet" but his left lung sounds relatively clear.   I'm surprised that CHF wouldn't result in accumulation of fluid in both lungs more or less evenly.

He had pneumonia in the right lung but apparently the last xrays show that as resolved.

[Cleveland Clinic]

It is unusual for fluid to accumulate in only one lng, as unless there is a venous obstrucion the left ventricular elevated pressures should be transmitted to both. If it is a result of severe mitral regurgitation it may concentrate on one lung because the jet is directed in that given area's pulmonary veins. It is more likely that he still has pneumonia, and it is taking a long time to resolve.