
Typically speaking, a company will use a glorified shop vac, various carpet
cleaning hose attachments in conjunction
with carpet cleaning machinery and or even a glorified shop vac with a spinning brush. Most contact cleaning companies will spend 30 minutes to 2 hours in attempting to reach as much ductwork that a person is physically able to reach. A small minority of contact cleaning companies will even make a good go at it and will spend up to 8 hours at an average residential jobsite. It is even fair to say that if a contact cleaning company spent all day, if the ductwork was completely exposed and if the ductwork was small enough, a contact cleaning company could technically perform a thorough job if the technician was motivated to perform a thorough job. The contact cleaning method of air duct cleaning is very limited in what dirt, dust and debris is actually pulled out of a ventilation and or HVAC system. 2” diameter vacuum hoses cannot suck up 3” diameter beer cans or soda pop cans.
That has delayed the product release for
quite a while, and also increased its price to $324, due to adding seemingly undisclosed additional features.

If you commit to a three year contract, the price of the Nest service drops to $19 per month. Ring's Protect Plus plan goes for $10 per month and doesn't require a contract. Monitoring for professionally installed systems tends to be
more expensive. The ADT Pulse
monitoring service starts at $28. 99 per month and requires a three year contract, but you also have to figure in the cost of things like hardware components, cellular backup, and installation. When we reviewed the Pulse system, our upfront cost was more than $3,000, with a monthly fee of over $60.