Insulation is a very important process of heat flow regulation. Good insulation materials provide comfort due to their ability to keep homes cool in summer and warm in winter. Through little or no emission of greenhouse gases.
The following are considered the best insulation materials.
The process of manufacturing aerogel is called supercritical drying through which ethanol is vented. Other materials required include; aqueous ammonia and silica solution.
Only 20mm of Aerogel achieves better insulation compared to other materials. On park homes, it is used to insulate external walls and their insides.
Although an expensive material, it is most effective for those ‘hard to heat homes’ and provides the best alternative where floor reduction space is an issue.
II. Mineral Wool
Two types of mineral wool manufactured are;
- Rock wool; manufactured from natural rock where limestone is heated at high temperatures of 1500c then spinning is done to turn them into fibers. The fibers are then passed through air which makes them finer.
- Slag wool; manufactured from the waste products of iron ore. It contains 75% of waste material and 25% of ballast.
Slag wool, though it causes irritation when handled, is very efficient and totals more than 80% of mineral wool produced. It is used for cavity wall insulation where mineral wool fibers are blown into wall cavities via a special hose pipe.
For best insulation on flat roofs and floors, consider the use of Cork. It is sound proof, a good insulator and keeps its original shape when trodden on. It is also soft with suberin (natural wax), impermeable to liquids, fire resistant, termite resistant and very light in weight.
Cork is produced from the outer bark of cork oak tree mostly found in the Mediterranean. After striping, the back takes eight to thirteen years to regrow. When large sections of the bark are punched, they manufacture bottle corks. For floor and wall tiles, they have to undergo baking and compression.
Form is the easiest insulation material to use since it is only glued to the wall like wallpaper and painted over. It also helps to hold together crumbling brick walls.
Urea Formaldehyde, usually confused with Form is a different kind of form piped into wall cavities and when drying it emits a product called Formaldehyde.
For internal wall insulation, dense latex form with fiber glass face is used
Flax has both temperature and moisture regulating qualities. It can absorb moisture when humidity is high and release it when humidity is low. The fibers of the stem of flax plant are extracted and used in the manufacture of flax insulator. It is very natural due to the fact that binding is by potato starch.
The most common brand is Isovlas, it is very secure thus can be handled without gloves and is delivered in slabs.
VI. Glass Wool
Knauf loft insulation/space blanket (0.035u) is an example of glass wool insulator. When manufacturing, fibers are obtained from super-heated sand and recycled glass. During this process, ‘not so safe’emissions are produced
When glass wool is burnt, it produces toxic smoke. Always handle it with gloves to prevent irritation.
When dry, glass wool is a very efficient type of insulator.
VII. Foil Quilt
For attic or loft conversions and roof rafters, foil quilt is the best insulation material. Numerous tough aluminium foil layers are sealed in quilt and delivered in 38mm thick rolls. The rolls are easy to cut and very safe to handle. Foil quilt is a relatively new insulating material.
Cotton for insulation comes in different brands. Isonat brand contains recycled cotton, hemp and polyester matting in a mixture of 42.5%, 42.5% and 15% respectively. When manufacturing ‘Polyester Matting’ is used as a thermoplastic binder and ‘hemp’ acts as a bulking fibre. For control of pests and combustion, borate is added.
Cotton, a non-allergenic material, absorbs and releases moisture and provides quality comfort.
With little energy, Newspaper is recycled then shredded to form cellulose loft insulation material. This material is very safe when handling.
Although paper could produce some smell, release ink and lose its fire retardation qualities when soaked, it is non-toxic, does not rot, does not attract vermin and has no negative effects on PVC used to cover electrical wires.
When recycled jute sacking material is added, board form is produced. It is treated with Borax to make it resistant to rot and fire. Examples of board brands include; Homatherm Board and Warmcel Board.
X. Perlite beads
Perlite is poured into wall cavities during wall construction. It is very light in weight and with numerous small air cells, it can penetrate through crevices, cracks and nooks to provide a perfect wall cover.
Perlite, when subjected to high temperatures of 900c, expands up to sixteen times of its original size.
Example of polystyrene brand includes kingspanKooltherm k7 and XtrathermEstra Performance.
During its manufacture, pentane gas which forms smog is released. Polystyrene unlike other form blocks is not manufactured from chlorofluorocarbons (CFCs) or Hydrochloro-fluorocarbons (HCFCs).
Polystyrene blocks can be reused or remoulded. Where machinery access is difficult in walls, polystyrene beads are encouraged. Beads are resistant to moisture, compression pressure and moisture.
When polystyrene is burnt, it emits toxic fumes.
Wood produces sawdust and shavings important for loft insulation. Compressed waste from wood mills is used in the manufacture of boards important for wall and floor insulation.
A very cheap form of insulation since it is natural. Can be used for roofing (thatching) or walls (through straw bale construction).
When straws are used, measures need to be taken to prevent intrusion by moisture, insects and decay. They are good replacements for timber and other costly materials.
Under compression, straw produces resin which binds it together. It is provided in slabs and bales which can be used for wall partitions, and insulation.
XIV. Sheep wool
Brands include; ThermaFleece (with 50/75/100mm thickness)
A good condenser since it can absorb moisture up to 40% of its dry weight. During summer time, sheep wool reduces temperatures up to 7% unlike other forms of insulation.
Quassi Chips of Unscoured Fleece are used in walls to prevent moths thus making it lifelong.
Sheep wool is provided in slabs from fleece offcuts.
Apart from it being used as a thermoplastic binder in cotton, hemp, on its own, can act as an insulator. During manufacturing, hemp does not pollute the environment and is provided in slabs. Examples include Thermo hemp and Hemcrete. Hemcrete is a thermally efficient building block.
Hemp is fire resistant due to Sodium Bicarbonate product added to it, offers good resistance to bugs and moulds and provides perfect moisture regulating qualities. It is also good for sound proofing