Your Flooring Matters.
Can we have underfloor heating with timber flooring? Yes, with warmth.nz underfloor heating (water based & heat pump powered)
Do we need underfloor heating in carpeted areas? Of course we do. No one wants cold bedrooms. The priority of underfloor heating is heating the rooms, then the floor surfaces. Heat will come out through the carpet but the effectiveness will depend on the specific product and underlay.
Please ensure your flooring suppliers know that underfloor heating will be installed.
Most floor coverings can be laid when underfloor heating is installed. However, thick carpet underlay and cork should be avoided – heat is effectively trapped in the slab which results in lower efficiency and therefore higher running costs.
The UK standard for floor coverings is that they should have a combined thermal resistance of no more than 0.15m2K/W.
What this means in practice is that tiles and polished concrete (for example) are very good. Timber overlaid or glued down is perfectly acceptable (but ensure the concrete is sealed or completely dry before gluing down). Vinyl is also fine – but ensure in all cases the slab is around 20 degrees prior to fitting.
In normal running with a hot water heat pump, the slab will not experience hot spots or localised overheating, in fact the sun can get the floor hotter than a heat pump. When there is significant solar gain, the underfloor piping can act as an energy transfer system.
Carpet is the only problem area, and the golden rule is to ensure that thick underlay is not fitted. Take advice from your flooring supplier, they should suggest either a thinner underlay or possibly specialised products available from the UK.
We have found where living areas have hard flooring, with carpets in bedrooms, that the blanketing effect of the carpet reduces the relative temperature without adjustments being made to the flow rates on the manifold.