Thermal Insulation Of Refrigerant Piping - Mitsubishi Electric CITY MULTI PUHY-HP-TJMU-A Instruction Manual

10.4. Thermal insulation of refrigerant
piping
Be sure to add insulation work to refrigerant piping by covering liquid pipe and
gas pipe separately with enough thickness heat-resistant polyethylene, so that
no gap is observed in the joint between indoor unit and insulating material, and
insulating materials themselves. When insulation work is insufficient, there is a
possibility of condensation drip, etc. Pay special attention to insulation work in
the ceiling plenum.
[Fig. 10.4.1]
C
B
A
D
E
A Steel wire
C Oily mastic asphalt or asphalt
E Outer covering B
Heat Glass fiber + Steel wire
insulation
Adhesive + Heat - resistant polyethylene foam + Adhesive tape
material A
Indoor Vinyl tape
Outer
Floor exposed Water-proof hemp cloth + Bronze asphalt
covering B
Outdoor Water-proof hemp cloth + Zinc plate + Oily paint
Note:
• When using polyethylene cover as covering material, asphalt roofing
shall not be required.
• No heat insulation must be provided for electric wires.
[Fig. 10.4.2]
B
E
A
B
C
D
E
A Liquid pipe B Gas pipe
D Finishing tape E Insulator
[Fig. 10.4.3]
14
B Piping
D Heat insulation material A
E
A
D
C Electric wire
Penetrations
[Fig. 10.4.4]
<A> Inner wall (concealed)
A B
<C> Outer wall (exposed)
E
B
I
<E> Roof pipe shaft
G
D
B
H
F
Sleeve
A
Lagging
C
Band
E
Sleeve with edge
G
Mortar or other incombustible caulking
I
Incombustible heat insulation material
J
When filling a gap with mortar, cover the penetration part with steel plate so
that the insulation material will not be caved in. For this part, use incombustible
materials for both insulation and covering. (Vinyl covering should not be used.)
• Insulation materials for the pipes to be added on site must meet the following
specifications:
ø6.35 to 25.4 mm [1/4 to 1 in] ø28.58 to 41.28 mm [1-1/8 to 1-21/32 in]
Thickness 10 mm min. [13/32 in min.] 15 mm min. [19/32 in min.]
Temperature Resistance
* Installation of pipes in a high-temperature high-humidity environment, such
as the top floor of a building, may require the use of insulation materials
thicker than the ones specified in the chart above.
* When certain specifications presented by the client must be met, ensure that
they also meet the specifications on the chart above.
(Unit: mm [in])
<B> Outer wall
D
C
A B
<D> Floor (waterproofing)
D
F
G
B
<F> Penetrating portion on fire limit and
boundary wall
I
J
A
1000 1000
[39-3/8] [39-3/8]
Heat insulating material
B
Caulking material
D
Waterproofing layer
F
Lagging material
H
Pipe size
100°C min. [212°F min.]