Design Enhancement That 'Significantly Increases Cabin Heat Output'

Power Flow Systems has engineered a design enhancement that significantly increases the cabin heat output for their Cessna 172 and 175 second generation exhaust systems (our p/n, PFS-13204). In the original design (dating from 2003), the cool air enters at the front left of the shroud, passes over the internal collector pipes which serve as heat exchangers, then exits to the cabin on the back left side of the shroud.

Unfortunately, they tell us that this was almost a direct straight-through pathway. The Cabin heat SCAT hose connection would then come out of the left side and have to snake its way back to the far right side firewall where the cabin heat mixing valve is located. For most customers, the heat output of the Power Flow was considered to be acceptable, but some flying in extremely cold temperatures told PFS that they wanted an improvement.

With the new design, they have made a vast improvement by relocating the cabin heat output and forcing the air to take a much longer path through the collector assembly which acts as a giant radiator. This forces the air to remain inside the shrouded collector area for longer and greatly increases the available heat inside the aircraft's cabin.

The new design’s output is a 2.0 inch tube that is on the right side of the engine. 2.0 inch SCAT tube, clamps and an adapter to go from 2.0 to 3.0 inches are provided so that the SCAT can travel back in a more direct path to the cabin heat mixing valve on the right side of the firewall.

Ground testing shows that this increased the heat output by 42% over the original Power Flow Systems design (from 100 degrees F to over 140 degrees) and by 27% over the stock Cessna exhaust (from 117 degrees to 140+).

Power Flow Systems Cessna 172/175 kits are now shipping the upgraded cabin heat system. Existing second generation PFS-13204 operators can purchase a complete improved cabin heat retrofit kit - it is our part number PFS-51724 and it is available now.

FMI: www.powerflowsystems.com