Timer for airconditioning? - diyAudio
Go Back   Home > Forums > General Interest > Everything Else

Everything Else Anything related to audio / video / electronics etc) BUT remember- we have many new forums where your thread may now fit! .... Parts, Equipment & Tools, Construction Tips, Software Tools......

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 5th June 2009, 01:09 AM   #1
thuur is offline thuur  Belgium
diyAudio Member
 
Join Date: Nov 2008
Default Timer for airconditioning?

Hi,

First of all: sorry if this isn't allowed, I couldn't find anything in the rules that it might be unwanted. If so, just delete this thread or move it to a better place

I've been looking for a DIY schema to make a timer. Well lots of those around, but let me explain my need.
I have a nice car with a pretty good AC system (and sound system ). The weak spot of this system is the evaporator. It costs about 120 euros but it takes 8 hours in the workshop to replace (complete dash has to be removed!). These evaporators literally rot from the outside in due to moist. Expected life span: 2 to 4 years

The only life prolonging thing you can do is to blow the fan on maximum speed for about 5 minutes after you turn off the engine or AC.

So, I'm looking for a timer that actives my fan for about 5 minutes after I turn off the engine (or a 12V supply gets disconnected). I don't mind having an extra switch to choose between the timer or not. I'll just set it on 'auto' (the same as the climate control) by default and incidentally on OFF when I didn't use the AC.

I have all the schematics of my car so turning the fan on and off will not be a problem.

Complete circuits and designs would be awesome, but I'll be grateful with some links or detailed ideas as well!


Thanks for looking!


Regards,
A
  Reply With Quote
Old 5th June 2009, 06:38 PM   #2
star882 is offline star882  United States
diyAudio Member
 
star882's Avatar
 
Join Date: Mar 2007
Charge a capacitor from the A/C compressor power with a diode and use a transistor to turn on a relay that keeps the fan on.

Check your local HVAC supply store. They probably will have a nice little module that does exactly what you want (it's something like an "off delay timer"). Probably wouldn't cost much more than a DIY circuit anyways.

BTW, pretty much all home A/C systems keep the fan on for a minute or two after the compressor turns off.
__________________
"Fully on MOSFET = closed switch, Fully off MOSFET = open switch, Half on MOSFET = poor imitation of Tiffany Yep." - also applies to IGBTs!
  Reply With Quote
Old 6th June 2009, 01:02 AM   #3
Ron E is offline Ron E  United States
diyAudio Member
 
Ron E's Avatar
 
Join Date: Jun 2002
Location: USA, MN
You live near the sea?

There are two things you can do other than what you are trying:
Have your evaporator dipped in a coating (Heresite) or
Use a copper finned copper tube evaporator
__________________
Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan
Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. Aldous Huxley
  Reply With Quote
Old 6th June 2009, 02:03 PM   #4
thuur is offline thuur  Belgium
diyAudio Member
 
Join Date: Nov 2008
Thanks for the replies guys!

I do not live near the sea. The evaporators are just bad quality. There is a choice between 2 or 3 brands, but no other materials than some tin can metal.

I will have a look at my local shop.


R,
A
  Reply With Quote
Old 7th June 2009, 04:07 AM   #5
star882 is offline star882  United States
diyAudio Member
 
star882's Avatar
 
Join Date: Mar 2007
Maybe zinc plate the evaporator to protect it from corrosion?
__________________
"Fully on MOSFET = closed switch, Fully off MOSFET = open switch, Half on MOSFET = poor imitation of Tiffany Yep." - also applies to IGBTs!
  Reply With Quote
Old 7th June 2009, 08:13 AM   #6
diyAudio Member
 
SoundOff's Avatar
 
Join Date: Apr 2002
Location: Birdlings Flat, New Zealand
A turbo timer would do the trick. These are intended to keep the engine running at idle for a few minutes after shutdown to cool turbo bearings down, then switch off. You should be able to adapt one for the vent fan.

Colin
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
First Timer needs help mgalvez Tubes / Valves 24 17th October 2007 11:34 PM
Need help with PIC timer. Tolik Parts 9 9th May 2007 11:02 PM
Help a first timer to select... CJ900RR Tubes / Valves 12 31st January 2006 05:46 AM
Timer Relay Bryan Tubes / Valves 6 15th September 2005 12:45 PM
555 timer latching nickch Parts 1 20th July 2005 09:48 AM


New To Site? Need Help?

All times are GMT. The time now is 05:42 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2