Couple of A/C project technical questions for the experts please

[mthomas58]

Putting my materials list together now and will start accumulating parts for my next project this winter (Kuehl Evap & Exp Valve, Rennaire Desert Duty front condenser, Procooler, Performance Aire underbelly condenser and hose conversion to barrier re-using orig fittings where possible)

(1) What size ID barrier hose do I use for the high pressure and suction hoses to re-use the old fittings? Bulk hose is avail in "Standard" and "Reduced" - most threads I've seen refer to "reduced" .

(2) Although I do not plan on evacuating or recharging the system myself, I would like some guidance on oil and refrigerant capacities (R-12) with the modified system to provide the proper oversight. Stock refrigerant capacity per factory sticker is 47.6 oz. and this is the exact quantity the dealership charged my system the last time.

(3) I've read in previous posts that a good rule of thumb is to add 1 oz of oil for every component replaced/added. Is this correct? Evap, front condenser, underbelly condenser and Procooler = 4. Any allowance for new hoses? Compressor? Finally, I know I've leaked some oil already out of the Evap (which was the impetus for this project)

(4) How much will the underbelly condenser addition increase my R-12 capacity? Or, is the new system capacity determined by the recommended charging procedure? (high/low pressure and vent temp monitoring, lid down, box fan blowing on static condenser, etc.)

(5) Flushing? With the exception of the compressor (orig) and rear condenser (repl last summer) every component will be new. Any need to flush?

Wow, this post took one full martini (rocks extra dirty with blue cheese olives-of course)!

Thanks!

[brcorp]

Here we go:

1.) Compressor to deck lid condenser #8, deck lid condenser to front condenser #8, front condenser to dryer #6, dryer to evaporator (expansion valve) #6, and finally evaporator to compressor #10. Use the reduced hose, it is lighter. Also the deck lid condenser to front condenser #8, requires a drop down fitting (#8 hose to #6 flare) as the front condenser is #6.

3.) For a dry install about 8 oz will be correct.

4.) Monitor dryer sight glass and pressures though 48 oz will be good start.

5.) No need to flush if system has not been exposed to elements. New parts (hoses) should be flushed with mineral spirits.

[Barrpete]

Mark,

From your project list you are basically purchasing the complete Rennaire System II except for the Sanden 507 compresser & adapter plate. You might want to price it out to see if you can get a "free" new compresser. Plus the kit includes all the hardware, O-rings, oil, black sticky tape for the expansion valve, new duct from the evap, insulation for the evaporator, nuts, bolts, etc. Then you would only have to modify one hose to tie in the underbelly condenser & all the other hose/fittings would be plug & play.

[derkpitt]

Don't forget to add a hi/lo press switch. Protects the sys in case of a failure.

[mthomas58]

Originally Posted by derkpitt

Don't forget to add a hi/lo press switch. Protects the sys in case of a failure.

Good catch!

Thanks