Insulated duct with air gap and method of use

In a method of making an insulated duct of R8 or R6 insulation value that includes a liner, a helical member, a layer of bulk insulation and a vapor barrier, the improvement comprising:

• a) making the liner free floating in the duct such that the liner is able to freely move at least transversely within the duct, and including a reflective insulation system in the duct, the reflective insulation system comprising a low-e surface and a gap between the low-e surface and the layer of bulk insulation, and positioning the helical member with respect to the low-e surface and the bulk insulation layer to form the gap, and either:
• b) using one of an R5 or R6 insulation for the bulk insulation layer to form an insulated duct having about at least an R8 value;
• c) using an R4.2 insulation for the bulk insulating layer to form an insulated duct having at least an R6 value;
• or
• d) using an R8 insulation for the bulk insulating layer to form an insulated duct having at least an R10 value.

A method of supplying conditioned air to a space using an insulated duct, comprising:

• providing an insulated duct, the insulated duct further comprising:
• a free floating liner that floats inside the insulated duct;
• a layer of bulk insulation surrounding the free floating liner,
• a helical member,
• at least one reflective insulation system comprising a low-e surface and a gap between the low-e surface and the layer of bulk insulation, and
• a vapor barrier forming an outside layer of the insulated duct,
• wherein the helical member, layer of bulk insulation, and free floating liner are positioned in the insulated duct to form the gap between the bulk insulation layer and the low-e surface;
• and
• further wherein the free floating liner is able to freely move at least transversely within the insulated duct;
• supplying conditioned air to the space using the insulated duct.

An insulated flexible duct comprising:

• an outer member,
• at least one free floating liner positioned inside the outer member, the free floating liner being able to freely move at least transversely within the outer member so as to form a variable space air gap between the at least one free floating liner and the outer member, and
• at least one reflective insulation system comprising a low-e surface on either an outer surface of the at least one free floating liner or an inner surface of the outer member and the variable space air gap, with the low-e surface facing the variable space gap;
• wherein the outer member serves as a vapor barrier.

An insulated flexible duct comprising:

• at least one free floating liner that floats inside an outer member and forms a variable space air gap between the at least one free floating liner and the outer member, and
• at least one reflective insulation system comprising a low-e surface on either an outer surface of the at least one free floating liner or an inner surface of the outer member and the variable space air gap, with the low-e surface facing the variable space gap;
• wherein the outer member serves as a vapor barrier, wherein the insulated flexible duct further comprises:
• a second free floating liner surrounding the at least one free floating liner so as to form the variable space air gap, the second free floating liner floating inside the outer member, the low-e surface of the at least one reflective insulation system on either the outer surface of the at least one free floating liner or an inner surface of the second free floating liner, a second variable space air gap formed between the outer surface of the second free floating liner and the inner surface of the outer member;
• a second reflective insulation system comprising a second low-e surface on either the outer surface of the second free floating liner or the inner surface of the outer member and the second variable space air gap, with the second low-e surface facing the second variable space gap.

A method of supplying conditioned air to a space using an insulated flexible duct, comprising:

• providing an insulated flexible duct, the insulated flexible duct further comprising:
• an outer member,
• at least one free floating liner positioned inside the outer member, the free floating liner being able to freely move at least transversely within the outer member so as to form a variable space air gap between the at least one free floating liner and the outer member, and
• at least one reflective insulation system comprising a low-e surface on either an outer surface of the at least one free floating liner or an inner surface of the outer member and the variable space air gap, with the low-e surface facing the variable space gap;
• wherein the outer member serves as a vapor barrier;
• and
• supplying conditioned air to the space using the insulated flexible duct.