A/C Upgrades vs longevity

[Campnjoe]

So I have been thinking about some of the A/C upgrades, especially the ones that enclose the output side of the unit. The wacko silencer and the rv airflow modifications in essence create a box for the output side. This causes, in some cases, higher pressure as the air is forced out the ducting. My question, since I am not a mechanical engineer, is due to this higher pressure, will it increase the wear and tear of the fan or any other part. I would hate to make things more efficient only to cut the life of the unit in half. Thoughts anyone?

[DavidEM]

The higher pressure, if any, would have minimal affect on fan motor life.

David

[reminckv]

I would not assume higher pressure. The fan is blowing the cooled air (output) straight down into the plastic cover. The air at that point has to be extremely turbulant as is makes it's way into the outlet ports. By installing the RV Airflow device, the air is directed in a much smoother transition from vertical to horizontal flow and into the ductwork. I didn't buy the RV Airflow, I'm a DIY'er and used the foam project board to make my own. By my experience with airflow, and by observing the increased airflow out of the duct vents, my eductated guess is that there is less restriction and pressure drop. And, any efficiency improvements in cooling makes the unit work less overall. Just my opinion, no data, but some relavent experience.

[Judge]

I agree with the above posts. The more efficent you can make the unts, the easier they will work.... and the longer they should last.

I have done many upgrades to my system and both are working as well as they can based on their design. I have been relatively happy with their performance in hot weather.

[Beau388]

Originally Posted by Campnjoe

So I have been thinking about some of the A/C upgrades, especially the ones that enclose the output side of the unit. The wacko silencer and the rv airflow modifications in essence create a box for the output side. This causes, in some cases, higher pressure as the air is forced out the ducting. My question, since I am not a mechanical engineer, is due to this higher pressure, will it increase the wear and tear of the fan or any other part. I would hate to make things more efficient only to cut the life of the unit in half. Thoughts anyone?

Fan theory states: the weight of the air moved and the pressure delivered equals the work done or HP required. As stated, the problem with most roof systems is the turbulent flow between the fan outlet and the ducts. If you decrease the turbulence flow (move to laminar flow), you decrease the restriction and increase flow. Increase flow requires more energy, but the removal of restriction lowers the pressure and decrease the energy required. Just be clear there is much more energy consumed to force air (increase in pressure) through a duct with turbulent flow as compared to the same duct with laminar flow. Since the air flow is three dimensional, the relationship is logarithmic.