Share 'Pressure testing practice in the classroom'

I just ordered the Retrotec house and duct simulator to use in our next HERS rater class and was wondering what other trainers do to give students practice with the pressure testing equipment in the classroom. Do you use a simulator? If so, which one? FSEC also has one, which they demonstrated at last year's RESNET conference. Are there others available commercially? Do you have one that your com…