def METHOD_NAME(self, val):
    """
    Sets the speed of all the FANs to a value denoted by the duty-cycle percentage val
    :param val: An integer, <0-100> denoting FAN duty cycle percentage 
    :return: Boolean, True if operation is successful, False if not
    """
    status = True
    pwm = int(round(self.PWM_MAX*val/100.0))
    try:
        with open(os.path.join(self.fan_path, self.fan_set_speed.format(1)), 'w') as fan_pwm:
            fan_pwm.write(str(pwm))
    except (ValueError, IOError):
        log_err("Read file {} failed".format(self.fan_path + self.fan_set_speed.format(1)))
        status = False
    return status