B-Kool Portable A/C

Moderators: Kai, Rick, Lance Murray, Mr. Gadget

User avatar
diamondchad
2 Diamonds Member
2 Diamonds Member
Posts: 13
Joined: Thu Aug 04, 2016 4:07 pm
First Name: Chad
Aircraft Type: DA40
Aircraft Registration: N971RD
Airports: KIWS
Been thanked: 1 time

B-Kool Portable A/C

Post by diamondchad »

I recently bought one for the summer here in Houston. It's an ice chest with a pump, heat-exchange coil and fan/blower. Powered through the cigarette lighter socket in the plane. 28Vdc. The unit works well however when I turn it on, I get a terrible noise on my radio which makes ATC etc.. darn near unintelligible. YIKES! Anyone have this same problem? Would a simple capacitor with a resistor (RC Filter) across the terminals do the trick? I checked tightness of the connections, all good there. The power leads to the unit are about 4 feet long and not shielded. I called B-Kool and spoke with Bob, he's very helpful and accommodating. He suggested I check power connections. I did, no luck. :(

Please help!
Chad
User avatar
Colin
5 Diamonds Member
5 Diamonds Member
Posts: 2006
Joined: Sat Aug 21, 2010 8:37 pm
First Name: Colin
Aircraft Type: DA42
Aircraft Registration: N972RD
Airports: KFHR
Has thanked: 319 times
Been thanked: 527 times

Re: B-Kool Portable A/C

Post by Colin »

http://www.bixnet.com/unpowbat.html

I would be curious what the B-Kool actually draws. This unit on Amazon is a little rechargeable battery and it would probably power the fan easily for the few hours you fly.

(It's nice to see N971RD in it's new home.)
Colin Summers, PP Multi-Engine IFR, ~3,000hrs
colin@mightycheese.com * send email rather than PM
http://www.flyingsummers.com
N972RD DA42 G1000 2.0 s/n 42.AC100 (sold!)
N971RD DA40 G1000 s/n 40.508 (traded)
User avatar
rwtucker
5 Diamonds Member
5 Diamonds Member
Posts: 1283
Joined: Thu Feb 21, 2013 11:24 pm
First Name: Rob
Aircraft Type: DA40
Aircraft Registration: N831BA
Airports: KFFZ KEUL
Has thanked: 100 times
Been thanked: 110 times

Re: B-Kool Portable A/C

Post by rwtucker »

Welcome to DAN Chad.

The interference is most likely coming from the blower motor.

The first solution I would try first is to place a ferrite core filter on the 24 VDC power lead. Placement of this filter can be critical. In general, you want to place it as close as possible to the source of radiation. Inside the cooler body, as close to the motor as possible might be your first choice if the layout permits that. Second best is to place the filter outside of the cooler, where the cable exits the body. Sometimes it can help to place a second filter at the point that the power cable enters the male plug that plugs into your auxiliary power outlet. If you have unused computer power cords or old video monitor cables in your junk box, you might be able to find a ferrite filter there. Higher end systems tend to come with these filters attached to the cords. Here is a picture and a link to a place that sells them as surplus for $1.00 each plus shipping. Search this website for "ferrite" and you will see several other ferrite filters in addition to the one pictured below. The one with leads may work well for an internal installation. Most of these filters are small. You can fix them in place on the power cord with a length of heat shrinkable tubing.
Image
http://www.allelectronics.com/make-a-st ... ead/1.html

If the first solution still leaves a little noise, you could try soldering a small non-polarized capacitor (metallized, radial film, etc.) across the blower motor's terminals. You could try anything from 0.05 to 0.1 mfd @50 volts or higher. Here is a link to capacitors at the same website so you can save a little on shipping. http://www.allelectronics.com/index.php ... capacitors

Good luck and let us know how it works.
User avatar
diamondchad
2 Diamonds Member
2 Diamonds Member
Posts: 13
Joined: Thu Aug 04, 2016 4:07 pm
First Name: Chad
Aircraft Type: DA40
Aircraft Registration: N971RD
Airports: KIWS
Been thanked: 1 time

Re: B-Kool Portable A/C

Post by diamondchad »

Thanks to all for the good replies. I will certainly look into the ferrite filter and perhaps adding a capacitor too.

Colin, not to worry my friend, 971RD has found a good home! I love it. It's obvious you took really good care of it for sure!
User avatar
BlackMammoth
4 Diamonds Member
4 Diamonds Member
Posts: 318
Joined: Mon Jun 20, 2011 5:50 pm
First Name: Phil
Aircraft Type: DA40
Aircraft Registration: N29PG
Airports: KPSP
Has thanked: 5 times
Been thanked: 23 times

Re: B-Kool Portable A/C

Post by BlackMammoth »

I am assuming that your fan & pump use brushed motors. When brushes are new they don't fit exactly and can create sparks (which generate noise). You might want to run the unit for a few hours (no need for ice, just water) to let the brushes seat and then see if there is an improvement.
User avatar
diamondchad
2 Diamonds Member
2 Diamonds Member
Posts: 13
Joined: Thu Aug 04, 2016 4:07 pm
First Name: Chad
Aircraft Type: DA40
Aircraft Registration: N971RD
Airports: KIWS
Been thanked: 1 time

Re: B-Kool Portable A/C

Post by diamondchad »

Thanks for the advice BlackMammoth, I've been using the unit now for a about a month. I have about 10 hours on it so far. It seems to be making the same noise as it did when it was new. I have yet to try Tucker's aforementioned solutions as of yet but will SOON. I'll report back with results.
User avatar
rwtucker
5 Diamonds Member
5 Diamonds Member
Posts: 1283
Joined: Thu Feb 21, 2013 11:24 pm
First Name: Rob
Aircraft Type: DA40
Aircraft Registration: N831BA
Airports: KFFZ KEUL
Has thanked: 100 times
Been thanked: 110 times

Re: B-Kool Portable A/C

Post by rwtucker »

One other thought. While interference like this commonly runs through the electrical connection to the motor, it occurs to me that your cooler is probably sitting on top of Garmin stack and it may be picking up local EMF direct. If so, you could have a faulty ground in the G-1000 wiring below your baggage area. If you have no faulty grounds (look especially at antenna connections), your last resort is to shield the interior of the cooling unit. That could be a lot of work and it might be easier to replace the motor with a low EMF emissions type.

Since no one else is reporting this problem, my mind is now focused on the G-1000 connections, grounds, etc. You could test this by turning on some other small motor in the area (electric razor, toothbrush, etc.) and see what you hear.
User avatar
Colin
5 Diamonds Member
5 Diamonds Member
Posts: 2006
Joined: Sat Aug 21, 2010 8:37 pm
First Name: Colin
Aircraft Type: DA42
Aircraft Registration: N972RD
Airports: KFHR
Has thanked: 319 times
Been thanked: 527 times

Re: B-Kool Portable A/C

Post by Colin »

I hope it isn't sitting in the baggage area. Having had a similar unit, one of the things that kept me from putting it in the plane was the worry of leaking a bunch of water in on top of the avionics. I think most people have them sit in the rear seat footwell.
Colin Summers, PP Multi-Engine IFR, ~3,000hrs
colin@mightycheese.com * send email rather than PM
http://www.flyingsummers.com
N972RD DA42 G1000 2.0 s/n 42.AC100 (sold!)
N971RD DA40 G1000 s/n 40.508 (traded)
User avatar
rwtucker
5 Diamonds Member
5 Diamonds Member
Posts: 1283
Joined: Thu Feb 21, 2013 11:24 pm
First Name: Rob
Aircraft Type: DA40
Aircraft Registration: N831BA
Airports: KFFZ KEUL
Has thanked: 100 times
Been thanked: 110 times

Re: B-Kool Portable A/C

Post by rwtucker »

Roger Colin. Didn't know. Still, if it is left side foot-well, it is still pretty close to avionics stack and quite a few RF connectors, grounding straps, etc. Diagnosing with another "RF noisy" electric motor in the area may be a time saver.
User avatar
rwtucker
5 Diamonds Member
5 Diamonds Member
Posts: 1283
Joined: Thu Feb 21, 2013 11:24 pm
First Name: Rob
Aircraft Type: DA40
Aircraft Registration: N831BA
Airports: KFFZ KEUL
Has thanked: 100 times
Been thanked: 110 times

Re: B-Kool Portable A/C

Post by rwtucker »

Chad -- I came across a snap-on ferrite interference filter in a box of cables in my shop. If you will PM me with your mailing address, I'll send it to you. It will provide a quick test of whether you are on the right track identifying the problem.
Post Reply