Heat Insulation Engineering - Carrier X-POWER Series Service Manual

Carrier service manual R410a DC Inverter 60Hz

6. Heat Insulation Engineering

The insulation of refrigerating equipment and pipe is carried out through general insulation method,
which binding the equipment and pipe with solid multi-hole insulation material and exploiting proper
wet-proof and protection measures, called insulation structure. The form of insulation structure shall be
different in light of different insulation materials. This is a traditional insulation method which is adopted
very early. Although its insulation performance is general, but it is simply in structure, convenient in
construction and cheap in price, so that it is widely used in refrigeration engineering.
6.1 Insulation of Refrigerant Piping
6.1.1 Operational procedure of refrigerant piping insulation
Construction of refrigerant pipe → insulation (excluding connecting section) → test for air sealing →
connecting section insulation
Connecting section: for instance, insulation construction just could be carried out after air tightness test
at welding area, opening expending area and flange joint is successful.
6.1.2 Purpose of refrigerant piping insulation
1. During operation, temperature of gas pipe and liquid pipe shall be over-heating or over-cooling
extremely. Therefore, it is necessary to carry out insulation; otherwise it shall reduce the performance of
unit and burn compressor.
2. Gas pipe temperature is very low during cooling. If insulation is not enough, it shall form dew and
cause leakage.
3. Temperature of outlet pipe (gas pipe) is very high (generally 50-100 ) during heating. Touching due
to carelessness shall cause hurt, so it is necessary to take insulation measures to avoid getting hurt.
6.1.3 Selection of insulation materials for refrigerant piping
Adopt hole-closed foam insulation materials with level B1of burning retardant and over 120 of constant
burning performance.
6.1.4 Thickness of insulation layer
1. When outer diameter of copper pipe (d) is less than or equal to 1/2in.(12.7mm), the thickness of
insulation layer (δ) shall be above 19/32in.(15mm).
When outer diameter of copper pipe (d) is more than or equal to 15.88mm, the thickness of insulation
layer (δ) shall be above 25/32in.(20mm).
2. In hot and wet environment, the above recommended value shall be increased one time.
Note: The outdoor pipeline shall be protected by metal case to proof sunshine, storm and air erosion,
and prevent damage of external force or man-made destroy.
6.1.5 Installation and highlights of insulation construction
1. Example of wrong operation: Gas pipe and liquid pipe are carried out insulation together; causing the
operation effect of air conditioner is bad.
2. Example of correct operation:
a. Gas pipe and liquid pipe are carried out heat insulation separately.
Installation 143