Air is sometimes used, but quickly becomes impractical under many circumstances because it requires large ducts to transfer relatively small amounts of heat.

"The air-handling system has been broken down into two or three distribution points rather than one mechanical room on the floor with large ducts coming out."

The cysts do not communicate with the larger pancreatic ducts.

They have a size ranging from typically 3 to 16 mm and are installed as bundles in larger ducts.

Sometimes they are installed as subducts in larger ducts.

These larger ducts can also consist of other materials, like concrete.

Cool air was returned through similar large ducts leading to the bottom of the furnace.

But these balloons have large ducts to vent excess gas at high altitudes.

Zeke looked carefully at the ceiling and found a large air-conditioning duct.

Suddenly as they were feasting, she let the river in upon them by means of a large, secret duct.