I also can confirm that Dennis Foley is someone that you should be cautious with. I watched many of his YourTube videos and ended up buying some of his products and plans he sold on his website. Unfortunately, buying those products was a huge headache and left me wanting me to warn others.
1) After a number of helpful discussions with Dennis, I paid $3600 for 900 pounds of activated Carbon that I would need to construct the units he determined would be necessary for my room. Even though I wasn't ready to do the work, he told me he was short on supply and wouldn't be able to have a new batch of carbon made for "a long while". He assured me that he would hold on to the carbon and ship it to me whenever I was ready.
2) After approximately one year (admittedly, I dragged my feet on the project), I contacted Dennis asking for my carbon, he told me that didn't have any carbon available and he had no record of me paying for it. I had to prove that I made a wire transfer to him and finally agreed to the transaction after I produced the wire transfer info. He told me that I would have to wait until the next carbon order (a couple of months later).
3) After contacting him again in a couple of months (when the carbon order should have been ready), he again told me that he had no record of me paying for the carbon. I would have to prove to him that I paid for the carbon order. In spite of the fact that I forwarded the email thread showing his earlier correspondence, this was insufficient.
His response:
"Please forward the receipt for proof of purchase under separate email per my instructions. You have our requirements that must be met. It is not my responsibility to produce your receipt for proof of purchase. It is yours."
4) After a number of emails which resulted in my resending the same bank transfer info, he agreed to send the carbon but indicated I would have to send an additional amount of cash to cover the shipping. Not wanting to go through the same rollercoaster and sending more money to him, I decided to use the money I already paid and adjusted accordingly. I ended up paying $3600 for 500 pounds of carbon, a box of acoustic foam, and shipping charges.
In the end, I ended up with something though it was less than what I was promised. I am a believer in the diffuser and BDA products that he sells. I use both in my room and they've made a huge positive difference. The experience and frustration with Dennis left a bad taste in my mouth, however, and made me vow that I'd never do business with him again.