Product review (5 stars): No Stinkbugs and Warm Toes
I give this product my highest regard, I found it when searching what people in extreem cold do for their homes. It stops the cold air from flowing into the house, no more cold toes when opening the dryer. It also Keeps out hot air in the summer. But, its biggest feature is that it prevents Stink Bugs from entering your house! as well as rodents and birds, It also prevents these animals from Nesting in your dryer vent which can be the cause of a disastrous fire! It may have some lint build up, but its REALLY easy to clean out as part of keeping a home one should clean out the dryer vent at least once a month and the lint trap on the dryer itself "Every Single Use". One would say that this product puts excessive back pressure causing longer drying times and increasing lint build up. This study was done with a Magnehelic gauge ( https://www.youtube.com/watch?v=cFOHGVhmyQA ) But you can always add a exhaust booster the best one is a "Tjernlund Products Dryer Duct Booster, Model# LB1" here is a video that demonstrates its use and how it works (https://www.youtube.com/watch?v=jwAiiKh9GVw ) In addition...This video is a must watch to help with the basic understanding of your dryer ( https://www.youtube.com/watch?v=xiqlFX0VRQo )
  The extra energy it uses to push out the air far outweighs your daily heating or cooling bill for your home, especially if your dryer vent is a Straight shot with no bends and less then 5 feet to the outside. The downfall is that its hard to find a Heartland 21000, but other companies are making them now and the concept is the same, very efficient if used properly and No, Bugs, Birds or Mice...and Warm Toes! Its a Win Win