hi just thought i'd share with you my simple project in making a clamp-on 12VDC Fan for the sump.
Eto yung materials and cost:
1. 12VDC adaptor (500mA) - P110
2. clamp-on (clip type) lamp - P90
3. 12VDC fan (surplus PAPST fan 4" 67CFM) - P150
Total cost = P350
Here are the materials when first bought
Assembled version
Here it is installed in my sump
Malakas din yung airflow and the fan is silent... works just great!
I plan to make at least 5 of these to put in my sump