Insulation – Essentials for Temperate Climes

Basically, insulation is the process of having a barrier to the heat flow that is needed in keeping your home warm in winter and cool in summer. A well-insulated home gives out year-round comfort, cutting cooling and heating bills for up to half the amount. In turn, it also reduces greenhouse gas emissions.

Climatic conditions have influence on the level and type of insulation. You need to establish whether the process is needed to keep heat out or in (or both). The process needs to cater to the seasonal as well as the daily variations of temperature.

Heat loss/gain  

If the insulation is installed but the house is not properly shaded, the built-up heat can be kept in by the process. This creates an “oven” effect.

Draught sealing is also important because draughts can account for up to 25% of heat loss in a home in winter. With the process, you can help in weatherproofing you house from moisture problems like condensation. 

Bulk / reflective insulation types

In bulk, the process mainly resists the transfer of heat (via convection and conduction). The basis is on the pockets of trapped air within the structure. The thermal resistance is essentially the same regardless of the direction of the heat flowing through it.   

The materials used in the bulk process include glass woo0l, wool, cellulose fiber, polyester and polystyrene. These bulk insulation products come with one material R-value for a given thickness.

Reflective insulation actively resists the radiant heat flow because of its high reflectivity and low emissivity (the ability to re-radiate heat). It relies mainly on the presence of an air layer at least 25 mm next to the shiny surface. (The thermal resistance of reflective insulation varies with the direction of heat flow.)

Ceilings / roofs

You need insulation under the roofing materials to reduce radiant heat gain. Install it in the ceiling to reduce heat gain and loss, mostly done in the joists.  To reduce risk in electrical short circuiting, the electrically conductive materials must not be laid across ceiling surfaces or ceiling joists or on subfloors.

The wall sections between ceilings of different heights (bulkheads) need to be insulated to the same level as the ceiling because they all are subjected to the same extremes in temperature.

Walls

The external walls should be insulated to reduce the heat produced by radiation, convection, or conduction. The installation on walls can be done within cavities, within stud frames, on the outside of stud frames or on the inside (or outside) of solid walls.

Depending on the present situation, some other forms of insulation can double as a moisture or vapor barrier.

Floors

Insulate the underside of suspended floors in cool temperature and alpine climates or in high humid and hot dry climates where air conditioning is used. Insulate the edges of slabs-on ground in cool temperate and alpine climates.

Raised timber floors need subfloor access to install insulation. Foil or bulk insulation works well but care must be taken to ensure it is well supported and won’t sag in time. Insulation is part of the set up in temperate climes.