We decided to turn on some heating on 30 October after the internal temperature dropped to 19 degrees. To begin with we switched on our underfloor heating circuits in the following rooms (all north facing)
2. Utility Room
3. Main Bathroom
4. Master en-suite
Our living rooms are all south facing so they benefit much more from the direct solar gain. On sunny days simply opening the internal doors (along with the heat recovery) ensure that the solar heat spreads evenly around the house.
Each room has a 270 watt circuit connected to a Dev 535 controller which allow timed start/stop and temperature control (measure via floor and/or room sensor).
Our house has a dual tariff meter so we decided to switch the heating on from 00:00 - 08:00 each day with the termostats set to 21 degrees. This will ensure the heating will only switch on if the room temperature is less that 21 degrees.
We are on the ESB ValueSaver NightSaver price plan with the current prices
Cost per unit Day - 19.62 (Inc VAT)
Cost per unit Night - 9.70 (Inc VAT)
With all 4 circuits switched on the total power consumption is 1080 Watts or 1.08KW (a single unit of electricity) the cost for each night is 9.7 x 8 hours = 77.6 cent.
This is the maximum cost as with the recent spell of sunny weather the internal temperature hits 21 degrees therefore the underfloor heating circuits do not switch on.