Ducts

A duct is a passageway, cylindrical tube, pipe or channel made of sheet metal or any other suitable material for transporting air, gases or liquids from one point to another. Ducts are, however, generally used for carrying and distributing warm air from heating plants to rooms or air from conditioning devices or cold air returns.

HVAC Duct HVAC stands fir heating, ventilation and air conditioning and HVAC duct is the passage way, a channel or a pile that is used for to deliver and remove air. The HVAC ducts supply, return, exhaust and ventilate air.

Ducts Article

Duct Design

Transport of air through a system of ducts is termed as ductwork. Planning, layout, sizing, optimizing, detailing and locating the pressure loss points in the net work of ducts is called duct design.

Duct Sizing

Ductwork can be sized by DM HVAC using the calculated CFM value. Ducts can be sized by using three different methods. They are constant velocity, constant pressure drop and static regain. You also need to specify the pre-requisites of size and shape of the ducts. You can make any combination of size in shape, width and depth and lock the settings.

Flex Duct

Flex duct by virtue of its flexibility restricts the free flow of air than the rigid duct. Flex duct, therefore, allows less of cold air to the living room due to the pressure losses during which the air gets time to warm up resulting in the loss of the efficiency of the air conditioner.

But flex duct is more suitable for short distances. It is imperative that the duct should be adequately sealed to the main line using mastic compound in addition to duct clamps. The duct should be insulated from outside to avoid spreading of fiberglass fibers through the house. In case of laxity in checking the joints, the expensive cold pressurized air blowing through the ductwork will find the weak points to leak and that would mean higher electricity bill for you.

Duct Insulation

The first step to insulate the duct is to seal all the joints in the duct run by using the mastic compound. The mastic not only seals the joints but also prevents the air losses and drop in velocity. Mast does not easily degrade or shrink away from the joints.

Now wrap the insulation jacket around the ducts and plenum. Duct insulation is typically made of rigid or faced fiberglass. The fiberglass surface should face towards the duct while the foil face protects the outside of the wrap. This arrangement prevents the heat loss and protects the fiberglass within.