Your HVAC system is too complex for the average person to try and fix or perform check-ups on. That is, unless you have the needed training and education. But, there are simple things that normal homeowners can do for the benefit of your HVAC. You can be observant with irregularities that occur while your system is operating. The scents that your equipment produce could be a sign of what’s wrong. This could help your technicians better diagnose and solve the problem. Strong Urine Smell If you get a whiff of urine coming out of your HVAC, it is likely that rodents have taken up shelter. They do this a lot to attract mates. These smells contain a lot of information about a specific rat. When one of the opposite sex finds their scent to be what they’re looking for, then they reproduce. No matter the reason, you don't want mice or their droppings around the heating and cooling system. Getting rid of this infestation is tricky. You can't use poisons as they might die in places that are hard to reach. Plus, the smell could end up getting worse if you are unable to remove them all. The best way to handle this would be to have professional get rid of them. If you insist, you may do so yourself with the use of traps.