Custom kit 183F

[MikeDelta]

CK 183F ENVIRO PRESSURIZATION SYSTEM INSTALLATION                                   18 March 2011

Provides an approved, alternative Environmental Control System. Note The -553 kit allows
 for upgrading an existing ENVIRO installation to the new Temperature & Flow control modules
& Flow sensor. For all serial numbers for Models 690C, 690D, 695, 695A, 695B, & also for all
serial numbers that have not previously complied with earlier modification to Gulfstream Dwg 880718
(Environmental system installation). For conversion from Sundstrand to Enviro, bleed air only.

Does anyone here have this kit installed? Does it offer much improvement? Can this be combined with the Keith system?

[donv]

Do you mean improvement over the old Enviro system, or improvement over the Sundstrand system?

Bruce and I seem to have a running Enviro vs. Sundstrand debate that pops up every so often... I think the Enviro system requires some sort of freon air, Keith or otherwise.

[MikeDelta]

I meant improvement over the old.

Also recall another website (was it Eagle Creeck?) that offered a refurbishment/overhaul/improvement of the complete system.

[donv]

I thought you were flying a 690? In which case, the Enviro system isn't applicable-- it's only for the Jetprops (840/900/980/1000). I think the Peter Schiff system is available for the 690, but I don't really understand why you'd bother.

The 690 has a heavy and large, but very reliable, Hamilton Standard (I think) ECU. The Jetprops have a much smaller and more efficient, but also much less reliable, Sundstrand ECU. The Enviro system replaces the Sundstrand ECU as a fix for the reliability issues.

In my opinion, much of the issue with the Sundstrand ECU is related to a) never checking the oil (which is basically impossible to do-- all you can do is top it off), and b) poor cooling airflow over the unit, which Commander fixed with a custom kit back in the 1980s.

[Adam Frisch]

I thought you were flying a 690? In which case, the Enviro system isn't applicable-- it's only for the Jetprops (840/900/980/1000). I think the Peter Schiff system is available for the 690, but I don't really understand why you'd bother.

I actually think the Schiff system is brilliant on paper. And the very few I've spoken to who have it really like it. It makes total sense to separate the pressurization system from the hot bleed air, which is just what they do. Aerotoxic problems are becoming better understood and with a Schiff system, that can never happen. Also, allegedly much more efficient, but perhaps to be taken with grain of salt. Heard the initial installations had some electronic problems, but that was taken care of.

[donv]

The problem with the Schiff system is that, in a 690, it's replacing a system which lasts a long time and works well. As you point out, there are some theoretical benefits, but they have to be pretty significant to justify the installation.

There is more of an argument for it in a Jetprop, where both the Sundstrand and Enviro systems have their issues.

[Adam Frisch]

Whichever way you look on the Jetprops - Sundstrand, Enviro, Schiff - you're looking at north of $100K. For a fancy Janitrol...