Commercial Building

  • Facade Insulation
  • Cavity Wall Insulation
  • Underdeck Insulation
  • Internal Wall Insulation

Ventilated Facade Insulation

A system of wall insulation where a ventilated air gap is ‘constructed’ after an external layer of galsswool insulation on masonry wall to provide good insulation value and meet the required energy performance. As a protective covering of the building skin, Ventilated Façade Insulation increases building life with superior aesthetics and is also easy to install.

Benefits and Advantages

  • Excellent insulation performance of building envelops. Meeting Energy conservation codes(ECBC-2007).
  • Protection from weather.
  • Allow water vapor to dry out through ventilated cavity and special insulation facing.
  • Other advantages like fire safety and acoustic benefit can also be achieved.

Specification

An external building wall made of 200 mm thick common brick and 12.5 mm thick cement plaster on both side, should be insulated with glasswool of 24 Kg/m3 density and 60 mm with factory laminated Fiberglass Tissue or suitable equivalent A 40 mm ventilated air cavity should be constructed after insulation by means of a Façade system comprised with anchors and Cladding. The overall Thermal transmittance or U-value should be less than 0.44 W/sq.m.K to conform ECBC-2007’s requirement. The insulation should conform to non-combustibility, Class-P(not easily ignitable), Class 1(surface spread of flame NIL), and Class ‘O’ rating as per BS 476 standards.

Installation

Glasswool insulation should be fixed with wall through plastic batten and screw anchor inside plastic( Rawl plug) to reduce thermal bridge effect. Insulation can be attached with the wall by using adhesive, too; but as adhesive cannot guarantee perfect adhesion to the irregular surfaces and can be degraded by atmospheric agents it is recommended to use mechanical fastening as described above. In new construction, both fixing methods may be applied.

Fixing System: FS can be of two types –

Local fixing

Anchors located at certain point to attach Outer cladding with wall.These anchors are made anticorrosive treated SS of AISI 304/316 grade or aluminum alloy. However these anchors acts as cold bridges and decrease envelop performance.

Spread Fixing

A structural frame, made of steel section bars arrange vertically and connected to the outer face of the floor slabs and beams through means of plates or anchors. To the vertical structures ,there are horizontal frames (secondary frames) to hold the external cladding.

Cladding

The cladding is not directly adhering to the supporting structure so that it can move independently with its own expansion coefficient.

Cavity Wall Insulation

Cavity Wall Insulation is one of the safest practices for wall insulation application. Twiga Insul boards are placed in between the cavity of the wall leaves. The insulation remains isolated from external and internal environment of the building.

Twiga Insul boards can be fixed to the internal side of external leaf by means of washer and screw and tie wires and then covered with internal leaf of wall. For vented or un-vented air gap between the insulation and internal leaf, Twiga Insul boards laminated with vapor barrier (FSK or WMP VR) is recommended.

With 50 mm thick Twiga Insul boards of density from 24-48 Kg/m3, excellent thermal resistance value (R-Value) ranging from 1.52 to 1.67 sq.mK/W and U-value <= 0.44 (ECBC compliant) can be achieved.

Specification:

A standard cavity wall insulation system should be comprised of a 230 mm brick wall, one layer of 50 mm thick glass wool slab having 24 Kg/m3 density, a 20mm air gap and finally 115 mm thick brick wall. The overall Thermal transmittance or U-value should be less than 0.44 W/sq.m.K to conform ECBC-2007’s requirement. The insulation should conform to non-combustibility, Class-P (not easily ignitable), Class 1(surface spread of flame NIL), and Class ‘O’ rating as per BS 476 standards.

Installation

  • The inner leaf of the wall construction should be cleaned of mortar protrusions before fitting glasswool slabs between each horizontal run of wall ties.
  • The mortar dropping should be cleaned from top of the insulation slabs before placing next row in position.
  • The mortar dropping should be cleaned from top of the insulation slabs before placing next row in position.
  • An air gap of 20 mm should be left between insulation and external wall leaf. This ensure normal drainage and ventilation of the cavities.
  • Joints between the insulation slabs should be close butted with all vertical joints staggered.
  • Insulation slabs are held back against the face of the inner leaf by drip prong of wall ties, special clips or adhesive.
  • During construction of the external wall the insulation should be temporarily covered with polyethylene sheet so that dirt, water cannot go inside the insulation
Composition
(Outside to inside)
Thickness,in mm Thermal Resistance,R in sq.m.K/W Thermal TransmittanceU in W/sq.m.K U=1/R-Total ECBC Compliance
Outer Air film - 0.044 Sandstone plaster 12.5 0.014 Common Brick 230 0.32 Air gap 25 0.15 Glasswool insulation (24 Kg/m3 density) 50 1.52 Common Brick 115 0.16 Inside Air film - 0.12
0.429
U(maximum)=0.44 W/sq.m.K Hence the system comply ECBC as the calculated U value is less than ECBC’specified U value
Total Thermal Resistance R-Total
2.328
Note : Other than Twiga Insul boards and sandstone R values, all values are derived from ISHRAE Handbook-Table no. 8, page no. 1.12-1.15.
For Sandstone plaster value taken from ECBC2007
Refer Twiga Insul brochure for R-value of Glasswool insulation.

Under-deck insulation

In Under-deck insulation system, Twiga Insul board is installed against the true ceiling to reduce heat gain or loss through it. Under-deck insulation system with Twiga Insul is one of the most cost effective methods to insulate building envelope.

Vapour barrier like Aluminum based FSK or Polypropylene based WMP-VR should be factory-applied on Twiga Insul and placed towards bottom side of the system. Under-deck insulation with Twiga Insul is easy to apply, cost effective and meets ECBC requirements.

Twiga Insul boards can be applied against true ceiling with the help of screws with GI washer or small angle-pieces and G.I tie wires.

With 50-75 mm thick Twiga Insul boards of density 24-48 Kg/m3; thermal resistance value (R-Value) of 1.52 to 2.5 sq.mK/W and U-value <= 0.409 (ECBC compliant) can be achieved.

Specification

Under-deck insulation should be done with glasswool having 48 Kg/m3 density and 70 mm thickness suitably installed so that the overall Thermal transmittance or U-value should be less than 0.409 W/sq.m.K to conform ECBC-2007’s requirement. The insulation should conform to non-combustibility, Class-P(not easily ignitable), Class 1(surface spread of flame NIL), and Class ‘O’ rating as per BS 476 standards. Please refer the installation guideline as mentioned below

Installation

  • The ceiling surface is thoroughly cleaned.
  • Fix soffit / clamp to ceiling by means of rawl plug/ dash fasteners.
  • Fix Z or C shaped GI channel runners or aluminium ones along the length of the room at 600mm spacing in one direction to the ceiling by rawl plugs/dash fasteners.
  • Apply any suitable adhesive to the ceiling and place slabs of Twiga Fiberglass insulation in between by spot sticking method.
  • Hold the insulation slab in position by 22 SWG GI lacing wire placed diagonally.
  • Apply 12 mm Gypboard or equivalent plaster board to cover up the insulation.

Energy Code Compliance : Under-deck insulation

Composition
(Outside to inside)
Thickness,in mm Thermal Resistance,R in sq.m.K/W Thermal TransmittanceU in W/sq.m.K U=1/R-Total ECBC Compliance
Outer Air film - 0.044 RCC 150 0.084 Glasswool insulation (48 Kg/m3 density) 70 2.33 Gyp board 12.5 0.08 Inside Air film - 0.16
0.37
U(maximum)=0.409 W/sq.m.K Hence the system comply ECBC as the calculated U value is less than ECBC’specified U value
Total Thermal Resistance R-Total
2.328
Note : Other than Glasswool insulation and Sandstone all values are derived from ISHRAE Handbook-Table no. 8, page no. 1.12-1.15.
For Sandstone plaster value taken from ECBC2007
Refer Twiga Insul brochure for R-value of Glasswool insulation.

Dry Wall Insulation

Dry Wall Insulation helps attain acoustic privacy and fire rating. Twiga Insul slabs are to be placed in the cavities of the grid structure for partition wall. Both side of the grid is then covered with single or multiple layers of Gypsum or fiber cement boards. When it is applied for Prefab structures the construction helps to provide thermal efficiency of the building, too.

With 25mm, 50mm, 75 mm, 100mm thick Twiga Insul slabs of density 24-48 Kg/m3,, STC value of 34 – 67 dB and thermal resistance (R-value) of 0.75 to 3.33 sq.mK/W can be obtained.

Energy Code Compliance : Internal solid wall insulation

Specification

The solid wall made out of 200 mm thick AAC blocks, should be internally insulate with 50 mm thick and 24 Kg/m3 glasswool and suitably covered with gyp-board or equivalent product. The overall Thermal transmittance or U-value should be less than 0.44 W/sq.m.K to conform ECBC-2007’s requirement. The insulation should conform to non-combustibility, Class-P(not easily ignitable), Class 1(surface spread of flame NIL), and Class ‘O’ rating as per BS 476 standards. Please refer the installation guideline as mentioned below :

Installation

  • Batten out surface of wall to suit width of insulation slabs.
  • Insulation slabs should be fixed snugly between battens without gaps.
  • Depending upon humidity a layer of pre laminated Vapour barrier can be used(optional) on insulation. The joints of the vapour barrier should be sealed with self adhesive Aluminum tape.
  • Fix expanded metal galvanized chicken mesh or plastic netting over the insulation as a key for rendering, fixing it into vertical batten with staples or flat head nails.
  • Final finish can be done with gyp-board or equivalent board.
Composition
(Outside to inside)
Thickness,in mm Thermal Resistance,R in sq.m.K/W Thermal TransmittanceU in W/sq.m.K U=1/R-Total ECBC Compliance
Outer Air film - 0.044 Sand Cement plaster 12.5 0.017 AAC block 200 1.25 Glasswool insulation (24 Kg/m3 density) 50 1.52 Gyp board 12.5 0.08 Inside Air film - 0.12
0.329
U(maximum)=0.44 W/sq.m.K Hence the system comply ECBC as the calculated U value is less than ECBC’specified U value
Total Thermal Resistance R-Total
3.03
Note : Other than Twiga Insul boards and sandstone R values, all values are derived from ISHRAE Handbook-Table no. 8, page no. 1.12-1.15.
Refer Twiga Insul brochure for R-value of Glasswool insulation.
Twiga Insul Duct Wrap

TWIGA Insul Duct Wrap Ductwrap, a light weight thermal insulation blanket having long product life is specifically designed to wrap around air conditioning ducts. Manufactured from fine, stable and uniformly textured non combustible inorganic glass fibers bonded together by a non water soluble and fire retardant binder.

Features & Benefits

Higher thermal resistance (R Value)

Minimising the loss of heat from the working fluid to the surrounding space will save energy and cost - provide uniform temperature of the supply air. It is noticeable that the efficiency of an insulation material directly depends on the thermal resistance(R - Value).

More thermal resistance less heat loss & gain inside the duct. To achieve higher thermal resistance (R-Value) is required more thickness of insulation material, if thermal conductivity of the insulation material is approximate same in same unit and mean temperature.

Thermal Resistance “R” Value

  • R = L K
  • Where 'L' = Thickness of Insulation material (m)
  • 'K' = Thermal Conductivity (W/m ºC)
  • “R” = m2 ºC/W or hr.ft2. ºF /Btu
  • R-Value is a measure of the resistance to heat flow of a material of any given thickness

Non Combustible

Prevent fire risks from the content of the services and protecting HVAC equipment from external fire damage.

High noise attenuation properties

Offers exceptional acoustic properties and enhances indoor environmental quality by absorption of mechanical noise generated by air conditioning equipment.

Condensation control

appropriate thickness of Insulation as per ambient temperature & relative humidity is used. The moisture carrying capacity of the air is related to its temperature.

When moist warm air comes into contact with cold surfaces eg. Pipe and ducts, the air is cooled and will produce precipitation on the cold surface.

Health issues/quality of indoor air

Fiberglass wool has no health hazard in any normal conditions. International Agency for Research on Cancer (IARC) monographs /WHO report (2002) explicitly states that glass wool is not carcinogenic to humans.

Facings

TWIGA Insul Duct wrap is available with a wide range of factory applied facings, FSK, Tough Guard, and Black Woven Glass Cloth & FGT.

Thermal Properties

Significantly reduces heat gain & losses.

Fire Properties

Non Combustible tested as per BS 476 part 4 and ISO 1182, IS 3808 & IMO (FTP)

Durability

  • Odorless, inert and fully compatible with all standard building material components
  • Does not encourage growth of fungi & vermin.
  • Non Hygroscopic

Tools needed for Installation

Tape Measure, sharp knife/blade, straight edge & strapping equipment

Installation Guidelines

The duct should be covered with two coats of cold applied bitumen/CPRX or any other equivalent approved product after cleaning the surface & sealing all joints against leakages.

The insulation of specific R-value and thickness should then be cut to appropriate length and stuck to the duct while the adhesive is still wet.

All longitudinal joints and circular overlaps should be sealed with aluminium foil tape (50mm width) to make the installation leak proof. For large ducts, where adhesive pins have been used, speed washers/clips should be covered completely with Aluminium foil- tape to have an air-tight finish.

The insulation should then be secured over the duct using mechanically fastened nylon/steel straps (12mm/50mm) at appropriate intervals (max 1.2m).

For ducts having width greater than 0.6m, heavy duty self- pins are to be applied to the duct at appropriate intervals (max 300mm)

Handling & Storage

Store product undercover and in dry conditions. Store flat. Handle with care, especially on the edges and corners, which can be damaged if subject to sharp or heavy impact.

Architectural Specification

Insulation material for Duct Wrap shall be lightweight blanket of non combustible Bonded Fiber Glass Wool Insulation - Supply Duct- having thermal resistance R 1.4 (24KG/m3-50 mm), Return Duct - R 0.6 (24kg/m3-25mm) suitably factory laminated with appropriate vapour barriers as per the ECBC/ASHRAE standards.