Underfloor heating with electric cables
No maintenance – only a timer and /or thermostat to control the usage of electricity. It can be used in conduction with other ways of heating to give a comfortable surface temperature of the floor-surface. Night-tariff could be used to minimize the costs per used kWh. The installation costs in a new house are lower than for any other system. The drawback is of course the dependency on electricity. This could be justified in a small and highly insulated house where the amounts of electricity used would be very small. Another bonus is that floor-heat cables embedded in the concrete raft can quickly dry out the concrete in a new house.
In practice it is only the very weak (approx. 200W) cables in each wet-room (bath and utility) that are used in most of our newer houses. It is used primarily to give super- luxurious warm bathrooms floors. The longer cable that stretches under the rest of the house is rarely or never used – no need in a passive house.
Together with PV-panels on the roof it is a great way to use up surplus electric energy generated on the roof. A problem is naturally that a passive house needs no space-heat at all for 8-9 months of the year in the mild Irish climate.