Update 8: The Heat Miser
Updated: Apr 15, 2020
I sound like my Dad ! He was always telling me to close doors and keep the heat in as a kid and I now know why !
The energy consumption in the original house was always on the high side at 72 kWh per day across the winter quarter. We have now increased the footprint of the house by 62% and added some seriously power hungry bits of kit like a swimming pool, jacuzzi and a moving floor. This had taken the power consumption up to an eye watering 118 kWh per day by late February this year, that’s £ 17.46 a day in energy cost, ouch !
The original Ground Source Heat Pump (GSHP), without any thermostatic control, was going like a runaway train. So we invested in a “Heat Miser” neo-hub solution, deploying five Neo Air 2 controllers across the house in addition to the thermostats running the pool and hot tub water, bringing this back to a central hub-controlled portal. Matching the heat pump’s control to this is not easy and more an art form than a science.
The results so far have been encouraging, with the average consumption dropping by a third to 76 kWh per day over the past 2 weeks. It is shocking that good temperature control can have that much effect, but there have been some complaints about the house temperature, particularly in the morning, prompting me to be known as the Heat-Miser ! I may have to yield and nudge the temperature up a tad !
The learning has been that GSHP systems react much slower than gas fired boilers and don’t react well to lots of stop/starts and ours doesn’t have a modern inverter starter which I would say is a must for a new system.
As the days lengthen, the solar generation has risen to an average of 27 kWh per day and now the storage batteries are filling up by early/mid afternoon and so I am exporting an increasing amount back to the Grid (7kWh per day). We are glad to be on the Octopus Outgoing tariff, but if honest, I'd rather find a way of using this energy.
So the net energy imported is now running at 64 kWh/day and thus we have reached our first milestone to be below last winter’s original house base line of 72 (Hurray !), which is a 35% reduction in energy per sqm.
But we are not done yet, we have the external wall insulation to add (planning consent delay :-( ) and some heat loss spots to eliminate and further time of day optimisation to go through.