Thanks....ive been racking my brain over the front ventilation for a week now but you cleared it up...I have always noticed how my HCM units eventually went a certain way, but they never asked me about ventilation and i didnt know what it was till i found this forum....that place was such a waste of time and money.....it makes me want to sit outside their door and handout pamplets over this site and products.....if people only knew!