Finding the chase and cutting to it

I am quite passionate about the benefit of having an EPC for your property. It is a valuable assessment of what you can meaningfully do to improve your home’s energy efficiency.

I don’t need to do that, even at today’s prices, I can afford it.

Even if you have an EPC certificate A, there are things to learn from the assessment. Although it is not fool proof. Sometimes the easiest and simplest things can help you make the most of the energy you buy.

For a start, the insulation on our home is deemed ‘good’ and ‘very good’, although our floor insulation has not been assessed (it got an ‘N/A’). We do have floor insulation and even internal wall insulation.

How do I know this? Well, I bought an infrared camera, and had a look. Our floors are cold upstairs: which means no heat is coming up through the ceiling of the rooms below them or the floor of the rooms in question.

The ceiling in our lounge is currently 20.3˚C. The floor in our bedroom is 16.3˚C. The rooms are 18.8˚C in the lounge and 17.5˚C in our bedroom. So there is no heat coming from the warmer lounge into our bedroom.

Your rooms are cold!

We don’t heat our bedroom after 9pm and that time slot we don’t heat over 19.5˚C; often that heating slot does not mean our room is heated because the room is warmer than that from the lunch time heating.

We then let the house just hold its heat as long as we can. If I’m paying attention, I close the curtains to stop heating passing through the windows. We have triple glazing and, even with triple glazed windows, it is worth closing the curtains. Suddenly we have quadruple glazed windows.

I love our glazing but a great window is not as good at stoping heat loss as a great wall. Curtains and blinds help make any window better at retaining heat.

We drop 2˚C from 9pm until 10am when the sun starts to hit our French doors and help our heating through solar gain. That and our heat pump heat our bedroom to 21.5˚C. When we start that at 2pm, we then let the room cool until 7:30pm, when we do a maintenance run. The sooner we close the curtains, the more of that lunchtime heat we keep in the room and get to enjoy not heating the room in the evening.

How is that working out for you?

I wouldn’t have the sophisticated heating controls that give me this information if it hadn’t been for the EPC that came with our buyers pack for the house: we moved in, after replacing the halogen bulbs, it was the first thing I did before we hit our first winter in the house.

But, while we had better control, the system gave us no information about how the house worked. My energy supplier gave a discount on a starter pack for the Tado system. It was expensive, but we got to see our solar gain, and tuned our heating round it. While we were on gas, it worked really well.

Now we’re on a heat pump, the benefits are clear. We take heat out of the air while it is warmer: while the sun is shining. Teamed with the heat pump’s settings, and you get an achieved coefficient of performance (COP) of electrical consumption (118 kWh) to thermal energy out (675 kWh), so 675/118=5.72.

That’s against an average air temperature of 12˚C over October 2026 in our town.

We’ve had hot water on tap. Typically we heat the water to 46˚C – for a household of three adults, that gives us three showers in the morning and then the water gets reheated during the early afternoon. We heat the house first (which requires less energy) and then the water once the air temperature has peaked.

We can think of the heat pump’s COP as being the miles per gallon (MPG) for an internal combustion engined car: the MPG quoted by the manufacturer is possible, as is the COP. But if you are an unsympathetic driver, you are unlikely to hit the theoretical efficiency. Using your heat well is being that sympathetic driver and it will reward you.

You got all that out of the EPC?

Sort of. The EPC has categories, each of these has a relationship to living sustainably. I then look at the information I am getting from all the sources with some questions in the search engines and reading papers.

Heat controls are a key part of the tooling: when paired with insulation, it allows you to tune your heating system to your needs. That’s allowed us to get a consistent COP of 4-4.2 per annum over the two and a bit years we’ve had the heat pump. I am hoping this year we do better than the 4.2 by harnessing the way the heat pump works to get the results we need: a toasty house. We are definitely making progress in that direction.

I’ve not got time for all that! It’s pie in the sky…

Again, if you have the information to hand, it all becomes much easier. It’s really why I do this blog. I share my experience so you don’t have to wait so long to get your heat pump where you need it.

Enjoy the warmth.