I purchased a Groupon for $51.00 for a Whole home air duct cleaning and furnace clean and check. The furnace did not need attention since it had been purchased three months before. I ended up paying an additional $479.90 (for what was suppose to be free to me (based on the coupon). It appears that the additional $479.90 did not cover what I had been led to believe I was purchasing since I suffer with COPD and it was "highly recommended". Now that I request a repeat treatment since I have had to change my furnace filters every other month instead of the 3 months recommended, I am told that I will need to pay for an additional $350 microbial treatment in order for them to reclean my ducts and will not honor the limited lifetime warranty that was suppose to be good for two years, however, in order to use the warranty you must purchase another microbial treatment. To me this appears to be rather deceptive and I would caution anyone to make sure what they are paying for before you sign off on anything.