Background:  

Our customers inherited a lovely home in a beautiful area which needed a lot of work to modernise it, as nothing had been done to the property in around 40 years. The property didn’t have a central heating system, instead relying on old electric heaters. 

The old electric heating system was costing around £3,500 a year to run, and that was from a few years ago. With current rising energy costs, our customers knew they had to do something. The property is off the gas grid and being environmentally aware, our customers didn’t want to put an oil boiler into the property. An air source heat pump system was an obvious choice for the property, especially with the introduction of the Boiler Upgrade Scheme to help with the installation costs. 

Solution:

We started with a site survey and formal room by room heat loss calculation to confirm the heating requirements of the property, enabling us to accurately specify a heat pump with sufficient output to keep the property warm the whole year round.  

We specified a Stiebel Eltron WPL17 AS Classic air source heat pump for the property. This home is west of St Just, right on the coast, so we needed a high-quality heat pump ready to deal with the elements. Stiebel Eltron air source heat pumps are blue fin coated as standard, which means that they are protected against potential corrosion from salt air. 

Inside the property we used the HSBC 200 S packaged cylinder. Instead of having the hot water cylinder and buffer cylinder standing side by side, with the HSBC 200 S, they are arranged in a single appliance, one above the other. This almost halves the footprint needed, so installation is possible even where space is tight. 

Result:

• A warm house with 100% of the space heating and hot water provided by the heat pump.
• A modern efficient system, ready to be complimented by the addition of solar PV and a battery installed in the new year, by Naked Solar, our PV partner.
• Reduced running costs compared to the existing direct electric heating.

Installation Photos:   

What Our Customer Thinks?

Having helped our mum moving between electricity suppliers, we knew how expensive it was to keep the house here warm and dry.  She stayed here till the end of her life; poor health the last few years meant a huge proportion of her pension went on heating.

Spending our savings on an air source heat pump, PV panels and a large battery (Tesla Powerwall) felt like the best decision we made.  Both environmentally and economically it feels the ideal choice for where we are. In Cornwall, where temperatures stay in double figures most of the year, but damp is a big problem, an ASHP works at optimal efficiency (they’re more efficient when the temperature differential isn’t huge, if only 10 degrees or so between outdoors and indoors the heat pump is around 400% efficient). I know this because my partner’s a geeky statistician, logging all the energy usage since installation in September. We called ours Mission Control.

For us it was quite an easy choice in a way: no boiler, oil or gas, just electric heaters, and for us it’s a lifelong investment. We planned to do more renovation work, so decided to retrofit underfloor heating, doing it ourselves and saving thousands of £s that way.  The environmental benefit means a lot to us too.  We live on an exposed bit of Cornish coastline so it’s impossible not to feel connected to the natural world.  Northerly storms batter the roof and wake us up.  A sunny day in January is uplifting whatever else is going on in the world.

We’ve become obsessed by energy usage and energy generation (our PV panels were installed 2 days ago – we’re avidly watching our Solar Edge app now).  It occurs to me that it’s really just like budgeting in a financial sense.

I don’t know why banks aren’t offering energy mortgages.  If/when we get a more socially minded government perhaps there’ll be loans offered to people who don’t have savings of £15-40,000 to spend on getting environmentally and economically beneficial home upgrades.  It benefits everyone except fossil fuel investors.  A good system has a warranty of 10-25 years and obviously increases the value of a property.  Giving people without savings an easy way to upgrade their home with a better heating system seems one of the best social programs we could have in the UK.

Here are the statistics on our place and what we paid:

• Annual energy usage when our mum was alive: 32,441kWh (yes, really.  It cost around £5000 in 2020, at todays prices that would be around £11,000/year).
• We don’t have the heating quite as high, but with underfloor heating it’s evenly spread, and prevents cold, damp corners of rooms.
• We got a £5000 BUS grant, meaning the air source heat pump complete installation package from Abode cost us £11,050.
• We spent a further £5,650 on an underfloor heating system from Continal, installing ourselves.
• The biggest investment was £26,644 for installation of 17 x 415W PV panels, invertor and Tesla Powerwall battery and gateway, from Naked Solar.
• The ASHP has cut our heating and hot water bills to less than 1/4 of what they were.  Instead of 30,000kWh for heating, water and all amenities, our estimate is around 7000kWh per year.  Our PV system is predicted to generate 7097kWh/year, pretty much the same as we use.
• At current electric prices, payback for the system overall could be in just 5 years.  And that’s only the economic benefit.