Mailing List lml@lancaironline.net Message #61850
From: Charlie Kohler <charliekohler@yahoo.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Necessity of A/C in IV-P?
Date: Fri, 04 May 2012 10:25:56 -0400
To: <lml@lancaironline.net>
hi Colyn
Yes-it worked out fine. By that- I mean- it was the best you can do.
In the beginning, The pressurized IVs had the cabin intercooler located on the side of the left lower cowling- with louvers. The intake air was taken from the engine air cleaner box. Even after moving the intercooler to the front/left side the air (thanks Don) into the cabin was measured at 105°on the 70° day.
What I didn't say in the post yesterday was that selecting 11,000 feet on the controller put an electrical signal to the outflow valve to open it wide open. You also could use the "dump" switch to open the valve. That helps a lot. But the big Issue is to shut off that 105° air from entering the cabin.
I liked the idea of the Airflow design--but I heard stories of airspeed penalties with the P51 scoop. I asked Bill Genevro if he had ever considered doing wind tunnel testing.Then they did-- at Ohio University. They tucked the condenser up closer to the fuselage and drag reduced drastically. I bought his system. At that time there was no choice.  I did testing later and saw less than three knot change--. The only holes cut in the fuselage was a pair of 1 inch holes for freon in and out of the condenser. The beautiful part of it, is that --it works. Very well! In all regimes.



Charlie K.
 
See me on the web at
 


From: Colyn Case <colyncase@earthlink.net>
To: lml@lancaironline.net
Sent: Friday, May 4, 2012 8:08 AM
Subject: [LML] Re: Necessity of A/C in IV-P?

Charlie, how did that work out?   You eventually added the airflow systems unit right?
Does that require a hole through the fuselage floor?

On May 3, 2012, at 1:20 PM, Charlie Kohler wrote:

LML gang
In the years before AC was available, I developed a plan for Summer (hot) flying. On take off I set the controller to 11,000 feet with the Pressurized air to the cabin OFF. I opened the air valve from the fresh air from the vertical stabilizer.

I took off and climbed to 11,000 feet . At 10,000 feet I closed the fresh aHim himir from the vertical stabilizer and gradually selected the pressurized air to the cabin to the ON position. Then as I continued to climb I selected the cruise altitude on the pressurization controller and adjusted the rate knob to 200 feet a minute descent. The cabin would then descend and level off 1000 feet above selected altitude.
On the descent into the landing airport-- I set the controller to 1000 feet above field elevation.

Complicated maybe--but it  kept the hot turbocharged air out of the cabin until it was necessary.
 
Charlie K.
 
See me on the web at
 


From: Jim Nordin <panelmaker@earthlink.net>
To: lml@lancaironline.net
Sent: Thursday, May 3, 2012 8:28 AM
Subject: [LML] Necessity of A/C in IV-P?

It can be really warn even at 17,000 feet without A/C in an IV-PT. Why? The bleed air is super warm. Absolutely necessary? Not IMHO. But a few letdowns from 20k+ and a drip drip drip off the end of your nose will tell you it’s nice. Or in summer heat in Houston, Phoenix or some other sauna, it is even better than nice.
Wouldn’t it be good to use that air to air heat exchanger in line with the bleed air to the cabin? HEAVY.
Jim

From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Dan & Kari Olsen
Sent: Wednesday, May 02, 2012 11:05 AM
To: lml@lancaironline.net
Subject: [LML] Necessity of A/C in IV-P?
 
LML Gang,
 
With all the discussion of structural integrity compromises of the IV-P fuselage by cutting air conditioning holes, I have a question for you seasoned IV-P drivers…  How necessary is air conditioning in this aircraft?
 
I have been flying my 320 for almost 9 years now and certainly would love to have had it during ground operations on hot summer days with the green house canopy.  However, once moving and at altitude, there is no need.  I realize that the IV-P is going to have warmer air because of the pressurization but it is also typically flying much higher (colder ambient) and it doesn’t have the bubble canopy.
 
So, in normal cross country cruise operations above FL180, do any of you that don’t have A/C *really* wish that you had it?
 
I’m early in the building of my IV-P and don’t want to put it in for several reasons:
·         Weight
·         Potential structural issues
·         Cost
·         One more thing to break down the road
 
I live in Colorado and will be using this plane as a cross country traveler with my wife, so comfort is certainly a factor but not at all costs.  One thought is to get one of those cooler-with-ice-and-a-fan systems to toss in the back seat for those few days that are very hot.
 
I appreciate your input.
 
Dan Olsen
Fort Collins, CO
N320DK – 640hrs
IV-P – 10% done





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