Yeah it needs the aspiration. That shield isn't made to be without a fan as it doesn't have passive airflow. If you've never replaced the fan you can get a new one from Scaled Instruments. If you still have the original T/H sensor I'd upgrade that too. You'd just need to tell me your serial number of your station to know if it can use the digital sensor or if it is analog only. Otherwise you'd need a new transmitter (a bit over $100) to be able to use it. Between the fan, T/H, and transmitter you'd now be around $200 so at that point maybe you'd be better off going entirely brand new. I still use the original station and just replace parts as need be.