The air is returning at a lower velocity, so you need a larger size duct.
The answer is quite simple, your duct work is not insulated somewhere. What is happening is the really cold air is blowing through the duct work and where it is not insulated, its causing condensation to form. It then builds up and starts dripping. You can either go to a hardware store and ask them for duct wrap or just buy a roll of fiberglass insulation and wrap it around and secure with duct tape.
It depends. If your bedroom has a supply AND return duct, then no. If there is only a supply duct, and you shut your bedroom door, this pressurizes the bedroom and limits the CFM delivered into the bedroom. A room to room vent or duct would equalize this pressure and allow maximum CFM to be delivered from the central air/heat system.
There are three main types of air ducts: sheet metal, pre-insulated, and flexible duct work. Sheet metal air ducts can be made of galvanized steel or aluminum, and may be insulated inside or outside with fiberglass. There are pre-insulated air ducts, which are relatively inexpensive to install, made of fiberglass duct board, polyurethane foam panels, or phenolic foam panels. Air ducts can also be flexible ducts, made of flexible plastic over a wire coil.
The supply duct system
The air is returning at a lower velocity, so you need a larger size duct.
A supply duct connected to the return duct somewhere? Fan running backwards?
Insulated duct work in a heating and cooling system helps to prevent energy loss, improve efficiency, reduce noise, and maintain consistent temperatures throughout a building.
The answer is quite simple, your duct work is not insulated somewhere. What is happening is the really cold air is blowing through the duct work and where it is not insulated, its causing condensation to form. It then builds up and starts dripping. You can either go to a hardware store and ask them for duct wrap or just buy a roll of fiberglass insulation and wrap it around and secure with duct tape.
If your are refering to the plenum being a large box say for air mixing the answer is no. you should have filter in return side however be sure you have access.
Using 4 insulated flex duct in HVAC systems provides benefits such as improved energy efficiency, reduced heat loss or gain, better temperature control, and quieter operation.
It depends. If your bedroom has a supply AND return duct, then no. If there is only a supply duct, and you shut your bedroom door, this pressurizes the bedroom and limits the CFM delivered into the bedroom. A room to room vent or duct would equalize this pressure and allow maximum CFM to be delivered from the central air/heat system.
Using 4 inch insulated flexible duct for HVAC systems offers benefits such as improved energy efficiency, reduced heat loss or gain, better air quality, and quieter operation.
screw type clamp
The answer is that "it depends". If the attic isn't insulated, put it in the basement to save on heating/colling costs. If your basement has a tendency to get damp, put it in the attic or you'll risk blowing mold and mildew around in a few years. Whatever area you put it in, make sure the ducts are well insulated.
Thoracic duct
There are three main types of air ducts: sheet metal, pre-insulated, and flexible duct work. Sheet metal air ducts can be made of galvanized steel or aluminum, and may be insulated inside or outside with fiberglass. There are pre-insulated air ducts, which are relatively inexpensive to install, made of fiberglass duct board, polyurethane foam panels, or phenolic foam panels. Air ducts can also be flexible ducts, made of flexible plastic over a wire coil.