In-slab underfloor heating systems, which use the slab to store heat, are considered as energy-saving solutions for heating up large areas. The efficiency of in-slab heating systems is affected by several variables such as soil conditions, ground temperatures, ground water, floor cover and distance from the slab to the surface of the ground, all of which can cause heat loss.

Additionally, in the absence of proper insulation, heated slabs won’t be able to store heat for long, making the system ineffective.

Insulation is a significant factor in the thermal efficiency of a home. If you are planning to install in-slab heating for your new home, you want to make sure you are not unintentionally losing that heat.

Comfort Heat Australia explains the importance of insulation under a heated slab.

Lower installation costs might mean higher utility costs

If you’re being offered a reduced construction cost for your in-slab heating system installation, there’s a possibility that insulation won’t be installed. Consequently, you’ll end up paying more in utility bills for the life of the house with the heating system using up more energy to compensate for the heat loss.

Insulation keeps the heat moving upwards

A heated slab without insulation will only have contact with the ground below, making it susceptible to that ground’s temperature changes. Installing insulation under the slab will reduce temperature swings in the heated space, increasing the slab’s response time to changes made to thermostat settings. Insulation also prevents radiant heat from moving down into the soil, not only retaining the heat but also increasing the heat that radiates upwards into the home.

Excellent slab performance

Insulation is mandatory if you truly want to achieve the best-heated slab performance. During installation, ensure that the insulation is waterproof, thick enough and extended deep and wide enough to prevent heat loss. This is important because heat loss can occur in a slab from two areas: you can lose heat from a downward heat flow from the slab, and you can lose it from the perimeter. The shortest distance from the slab to the outside is at the perimeter consisting of the band of earth, concrete or block around the edge of the slab. Extending insulation beyond the borders of the perimeter will help ensure there’s no heat loss from any of these sources.

Slab edge insulation will address any concerns about perimeter heat loss from in-slab heating systems, especially those installed in a basement area.

During installation, leave a thermal break between the slab and any direct path to the outside. This is because contact between the edge insulation and a foundation or wall that isn’t insulated can cause the heat to travel up the wall to the outside.

Consult with Comfort Heat in Sydney for electric in-slab and hydronic in-slab heating solutions as well as insulation.