My family and I have three dogs and a cat and it can be difficult to keep the house clean. My wife and I sweep and mop the living room, kitchen, dining room, and hallway every other day. We cast all of the surfaces in the house on Saturday morning. We also change the air filter in the heating and air conditioning system. The air filter gets changed every three weeks. We used to change the air filter monthly, but it was always covered in dog hair and dust by the time we changed to a new one. We decided last year to change the air filter every 3 weeks and I really do think it improves the indoor air quality. Last weekend, it was time to change the air filter in the heating and air conditioning system. I had a brand new box mailed from the store and I opened it up that morning. I pulled one of the air filters out of the box and I took off the protective plastic. I tried to place the air filter inside of the heating and air conditioning system, but I quickly realized it was way too big. I double checked the size of the air filter and it was marked with the same numbers as my old air filter. I replaced the two air filters up to one another and they were clearly different sizes. I found a tape measure and I decided to check the measurements on each one of the air filters. The new filters in the box were marked with the wrong size. I had to call the company to get a refund.