Hvac Flex Duct Installation

In our retrofit work we d rather see a customer with a well design and installed duct system where flex is used appropriately then have the homeowner keep a poorly designed and installed duct system because they can t afford the cost to replace it with sheet metal.

Hvac flex duct installation. Flexible ductwork is a very popular because it is easy to install and has great insulation potential flexible ductwork is often made from flexible metals such as tin or aluminum also metal fiberglass or plastic. If internal core is penetrated replace flexible duct or treat as a connection. But without proper support ducts can develops sags or kinks that reduce airflow 4a 4b. On the ducted projects we use flex for the branch runs to the supply boxes.

Design of flexible duct junction boxes current standards ashrae 2012 hvac systems and equipment box plenum systems using flexible duct constrains box width to 2 3x entrance width constrains box length to 2 x box width flat pressure loss 0 05 in. To prevent problems use saddles or straps to support at regular intervals 4c 4d follow the manufacturer s instructions but in case they get lost here is a list of best practices for. Sometimes the best route for a flexible duct run is up and over an obstruction. Terminal devices shall be supported independently of the flexible duct.

The air duct council adc formerly known as the air diffusion council is a recognized hvac industry standards body for the dissemination of flexible duct installation details and performance metrics for efficiency and quality regularly referenced by government agencies architects engineers manufacturers and hvac contractors. We keep those flex runs short on the order of 5 to 15 feet. 1 10 5 25 per foot insulated flexible duct 4 to 16 diameters used as branches or in radial duct attic systems 2 30 13 00 per foot round and oval sheet metal duct 3 to 8 diameters typically used for trunks in small homes and. Cost of installation supplies.

Within the hvac system will cause degradation of some inner core liner materials. There are times where flex duct or sections of it can help to reduce costs. Flex duct installation we install a lot of hvac systems on martha s vineyard ranging from mini splits to fully ducted. Of water 50 ft of el mentions entrance fitting.

Some kinds of flexible ductwork can also be made from vinyl insulation which is extremely easy to fit on your own. Here are the itemized costs for the most common types of ductwork and supplies needed to complete installation.