This results in no efficiency improvement when cleaning out the burners, because the shop
vac hose could not fit inside of the burners to properly clean it as compressed air or nitrogen can. Most ventilation and or HVAC systems have portions of ductwork that is not easily accessible due to portions of the ductwork being drywall finished around. Should this be the case at any given jobsite, a consumer and or customer must realize that a large portion of ductwork will not be cleaned as a result when the contact cleaning method of air duct cleaning is employed. Typically a shop vac hose can only reach up to 15’ before the hose just curls up. Some trunk lines may stretch out to over 100’ in distance, which means 15’ would be cleaned and 85’ would go untouched. 90 degree turns will almost always make the shop vac end its descent
in cleaning down a pipe because the shop vac hose cannot be turned without physical intervention.