- High loss of fan static pressure due to high friction in flexible duct used you used much extra lengths of flexible duct. - life time of flexible duct is not long. - what is this round under ground duct used for? Is it for exhauat or what? Plus hou you put sheet metal under the ground , after a short time you will not find it
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- High loss of fan static pressure due to high friction in flexible duct used you used much extra lengths of flexible duct.
- life time of flexible duct is not long.
- what is this round under ground duct used for?
Is it for exhauat or what? Plus hou you put sheet metal under the ground , after a short time you will not find it