Air-Source Heat Pump – 1 year later

10 months ago I wrote a blog post Air-Source Heat Pump – our experience so far, 2 months in about our new air source heat pump. Have a look back at that for photos of the device itself and more detail about installation etc.

Less energy

We used a lot less energy this year than last year. Here’s the graph for 2 years:

Graph showing 2 years of energy usage on gas and electricity. Gas usage stops halfway through because a heat pump was installed. The second year's gas usage is much lower than the first, especially during the heavy use, cold months.

As you can see, we used a lot less energy in kWh this year than last year. Air source heat pumps work!

More money

Our energy cost more this year than last year. I’ve calculated this graph based on fixed prices, and I used 2021 prices to keep consistency with the last blog post, but the real-prices story is similar. Here is the graph for the last 2 years:

Graph showing energy cost per day over 2 years. The first half shows gas usage, which drops to zero in the middle when a heat pump was installed. The second half is higher, showing that the cost of the electricity this year was more than last year. Towards the end, solar panels were installed and the cost drops below last year.

Why did our cost go up when our energy usage went down so dramatically?

Because electricity is too expensive!

Electricity is the right way to power our cars and homes, because it can be sourced sustainably, and in fact much of it really is being sourced sustainably right now.

Artificially-high electricity prices are preventing people switching to a better way.

Solar panels help!

In September this year we had solar panels installed. They look great and are working incredibly well. We were getting 10kWh per day from them in September. We don’t have a battery yet, but when it arrives we think we will be able to cover most of our summer energy costs using these panels.

Since the panels were installed, our reduced use of grid electricity meant that our energy costs for this year dropped below last year. Obviously it’s too soon to say for sure what the full impact is, but I can say we are very happy with our solar panels.

Our house is cozy

Our new heat pump heats our leaky house very well, and we are nice and cozy, even when temperatures outside drop below zero. The heat pump is less efficient when it’s cold outside, but still way better than a gas boiler.

Installed by Your Energy Your Way

[My wife used to be director of the company, so I declare an interest.]

Our heat pump, radiators and panels were installed by Your Energy Your Way and I can recommend them for good communication, service and quality.

Deporting desperate people from the UK

Letter to my MP on deporting refugees to Rwanda, 2022-06-06.

Dear Ben Spencer,

Please do what you can to reverse the policy of sending asylum seekers to Rwanda.

We are breaking our proud tradition of commitment to refugees.

This policy seems to have the intention of preventing people from drowning while attempting to enter the UK. Instead of ruling people’s claims “inadmissable” because they were desperate enough to enter by a dangerous route, we should provide safe routes for people escaping war and harm.

I am sure this policy was drafted with good intent, but immediately it started we have seen disproportionate numbers of Sudanese people being deported to Rwanda [1] verses other nationalities. Even within the parameters of its own flawed morality, this policy is unfair in practice. It should be stopped immediately.

[1] https://www.theguardian.com/uk-news/2022/jun/06/home-office-offers-asylum-seekers-choice-between-war-zones-they-fled-and-rwanda

Yours sincerely,

Andy Balaam

If you want to write a similar letter, feel free to use any of the above if it’s helpful. I used WriteToThem.com as a very easy way to find your MP and send a message.

Air-Source Heat Pump – our experience so far, 2 months in

[Update: see also Air-Source Heat Pump – 1 year later.]

Summary: less energy, more money

2 months ago, we replaced our gas boiler with an air-source heat pump, which uses electricity to heat our home and boiler. This is a report of our experience so far.

We expected it to reduce our environmental impact, and cost us more money, and we were right.

It works: our house is comfortable. We use a lot less energy, and it costs us significantly more money (because electricity costs way more than gas).

The house

Our house is a beautiful, leaky old house, with a modern extension. Half of it is well-insulated. The other half was built around 1890, and while we do have double-glazing and decent loft insulation, the walls have no cavities and feel cold to the touch, and there are drafts everywhere.

The new half has underfloor heating. The old half and the upstairs are heated by radiators. We have a hot water cylinder.

The air-source heat pump

Our air-source heat pump uses electricity to extract heat from the outside air and heats water for radiators and hot water, directly replacing our gas boiler.

Our heat pump was installed by Your Energy Your Way and I must declare in interest: my wife is a director of the company.

The heat pump is an LG 16kW “THERMA V” model. It looks like a very large air conditioning unit, which sits outside our house in the yard to the side. It is about as tall as my shoulder height, with two big fans on it.

A large air-source heat pump

It stands on a soak-away area with some stones on it that the installers made by removing some patio tiles. This is needed because it drips a small amount of liquid as part of its normal operation. The outdoor unit makes noise, but our house is next to the main road, so we don’t hear it. It is not audible indoors.

Standing next to the outdoor unit you can feel a cold breeze, like opening the fridge door. This is unpleasant on cold days.

That outdoor unit connects through the wall to an indoor part that is a bit smaller than our old boiler.

The controller box has a terrible user interface and is very hard to decipher, but we did eventually manage to programme it to turn the target temperature up in the daytime and down at night. Your Energy Your Way advised us that it is more efficient to keep the house at a cool-ish 17 degrees at night, rather than letting it get cold and having to work hard heat it up again in the morning, so that is how we have set it up.

The controller box’s built-in thermostat does not work properly (it reports the wrong temperature), so we had to add an external thermostat, which works well.

We didn’t need to change anything about our hot water cylinder, or our underfloor heating.

When planning the installation, Your Energy Your Way estimated the heat loss of our rooms, and recommended upgrading our radiators. In an old house like ours this is sometimes needed, because it is way more efficient to heat a house with cooler water running through the radiators, but if the water is cooler, you need more radiator surface area to heat the house effectively. In a newer house with existing radiators, they are probably fine as-is.

We kept most of the existing radiators, and added some more in the coldest rooms.

How comfortable is the house?

The house is more comfortable than it was before, for two reasons: firstly the radiators we had were not really adequate, and secondly the cooler water in the radiators makes a less irritating heat, meaning the house is nicely comfortable most of the time, instead of bouncing between feeling cold and feeling oppressively over-heated.

On cold days, the old part of the house is a bit cold, but I think on average it’s a little better than it was before.

We do find mornings can be chilly, particularly because the system stops heating the radiators if the hot water cylinder needs heating up after people have had showers. We could improve this situation by getting a larger cylinder, which we are considering.

However, it’s worth pointing out that we needed engineers to visit four or five times to make adjustments before we felt the system was working well enough. There are a lot of things that can be tweaked, and it took some time for it to work well.

My advice: don’t pick the cheapest quote – pick the people you think you can trust to do the work well: especially the heat loss calculations before installation and the adjustments afterwards.

How much energy are we using? (The good news)

So far, it looks like we are using about two-thirds less energy in our household than we were before:

The above chart is stacked, so the top line represents the total energy usage. We switched to the air-source heat pump exactly when our gas usage was about to skyrocket (because it’s cold in winter), and it remained relatively low.

This is absolutely fantastic: our house is more comfortable than before, and we have reduced the amount of energy we are using by 66%. This is the total energy usage of our house, not just for heating, so the reduction of energy used for heating is even more dramatic than it looks.

Even better, the energy we use is at least partly produced from renewable sources, so our carbon footprint is much lower. Previously we were directly releasing carbon by burning imported gas – now we use mostly UK-produced electricity, and as the grid decarbonises, our carbon footprint reduces even if we make no further changes.

How much money are we spending? (The bad news)

Excluding standing charges*, we are spending about one third more on energy than we were before. This is because electricity is so much more expensive than gas: our electricity costs 19p per kWh and our gas costs 4p per kWh.

* Note: our energy provider wanted to charge us £350 to remove our gas meter, so we refused, and are still paying the gas standing charge. I’m not sure how we’re going to resolve this, especially since our energy provider is now in administration.

The above chart is stacked, so the top line represents the total cost (excluding standing charges). When we switched to the air-source heat pump, our energy costs increased faster than they did the same time last year, and were consistently higher. We think the peak in November might be misleading as it may have been when the system was not set up correctly, but we are not sure.

Because air-source heat pumps are more efficient when the weather is warmer, we do expect to fare better in the summer than we are right now.

I would not suggest getting a heat pump if you want to save money. Maybe this will change as gas prices are expected to rise significantly this year.

An installation like ours, including new radiators, costs £10-15K. A decent chunk of that will be paid back to us by the government, spread out over the next 7 years, under the soon-to-be-gone Renewable Heat Incentive (RHI). RHI will be replaced by the
Boiler Upgrade Scheme (BUS), which will be limited to a £5K grant for air-source heat pumps, although it is paid up-front. We would have received much less money under BUS than RHI. It is almost certainly too late for you to get a heat pump under RHI, by the way – all the installers are booked up until end of March 2022, when it ends.

Thoughts

If you think it’s surprising (and deeply concerning) that taking the step of significantly reducing our carbon footprint cost us a one-third increase in our energy bills, I would agree with you.

I am told that the tax taken on electricity is much higher than on gas, even though these taxes are apparently intended help decarbonise our energy.

Meanwhile, the government is replacing (with great fanfare) RHI with the much less generous (although more timely) BUS, making it even more economically punishing to reduce your carbon footprint.

I think this should be addressed urgently: money should be provided to help people install heat pumps, and the tax regime should be changed to make it cheap to use low-carbon fuels.

The technology is available, but the financial situation makes this a vanity project for people like me who can afford it, instead of what it could be: a feasible plan to get our national carbon usage down, fast.

On a positive note, our house is nice and warm, and I feel a bit less guilty about how much carbon we’re using to keep it cosy.

[Update: this was written in January 2022, and we live in South East England.]

Letter to my MP about climate emergency

[Introduction including details about my own air source heat pump install, and mention of the ending of the RHI funding in April 2022.]

After I have installed an air source heat pump, I will pay more money to heat my home, even though I am using less energy, because electricity is more expensive than gas. So this change will hurt me financially over both the short and longer terms.

Do you agree with me that climate emergency is the most important issue the government is now facing?

Do you also agree with me that we urgently need people to switch their heating and home insulation to reduce our dependence on burning gas?

Please do all you can to persuade the Prime Minister to introduce initiatives before COP26 that make it financially viable for families without spare cash to insulate their home and heat them with renewable energy.

Please pass my letter on to the Prime Minister and any government departments you consider relevant.

Thank you very much for your time.

Letter to my MP on Yemen

Sent via WriteToThem on Monday 1 March 2021.

Dear Ben Spencer,

Your experience on the front line in medicine means you are probably much more able than I to imagine the human impact of the situation in Yemen.

On Sunday OCHA stated that 16 million people will go hungry this year, and nearly 50,000 are already living in famine-like conditions.

How can the UK government throw away its position of leadership on this matter by cutting funding at such a desperate time? I share the urgent concern expressed by Andrew Mitchell this morning.

I would be grateful if you would pass my concerns on to the FCDO.

Yours sincerely,

Andy Balaam

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