Louise Howlett, Interview with an Energy Efficient Heating Expert

airsourceheatpumps energy efficiency epc gas boilers radiators ufh Aug 03, 2023
air source heat pumps

Hi Louise

 Just to set the scene for our readers quickly and share a recent survey, the UK is almost stagnant behind 19 European countries in our uptake of ASHPs.

We are however, at the tipping point of seeing a huge surge in the installation of heat pumps in the UK out of  pure necessity to reduce our energy usage and carbon emissions. Currently women homeowners are held back by high electricity costs over gas, ineffective government schemes to reduce installation costs and frankly as we recently talked about lobbying that is creating a considerable amount of confusion in this area.

I am so grateful to have someone with your knowledge here to talk to us in. Her Own Space” and help us navigate this area..

1. You have worked for over 15 yrs for R A Brown Heating and in your own home we talked about why you have an Air Source Heat Pump. What would be a typical project you would undertake?

Weve been installing heat pumps for 15yrs and Ive been working in the plumbing and heating sector for over 20 years, since marrying a heating engineer. We have always had a strong ethos of training our own engineers, not just having a sales team and relying on a technical sales approach with a focus on solving the customers problem. We opened a showroom, in 2012, to enable customers to see how products could fit into their property. Weve retrofitted many of the products we offer into our own house. This means we can explain what it is like to live with these systems. We currently have a Stiebel Eltron air source heat pump, mechanical ventilation with heat recovery (MVHR), underfloor heating (this was installed when the house was built and extended when we built on a garden room), with some radiators upstairs. We have a PV system on our garage roof, attached to 10kw of battery storage. Our very first heat pump customer booked the installation when we were also installing a heat pump into our property.

A typical project we undertake is a large bespoke new build, barn conversion or refurbishment in rural Norfolk or Suffolk. We offer a complete plumbing, heating and ventilation spec, design and installations service. This really helps customers’ who are project managing themselves. 

We also undertake all kinds of retrofit projects including hard to treat’ properties We recently won a national award for installing a twin air source heat pump in a 200 year old house.

Weve worked on Grand Designs projects, executive housing estates, National Trust cottage refurbs, Community halls, thatched cottages so all ages and shapes of sizes of properties.

2. What is the feedback from your customers once they have made the change over to ASHPs?

What customers comment is that at a certain point in their first autumn or winter with a heat pump they completely stop noticing the system. They just feel comfortable. I call it the Goldilocks effect: not too hot, not too cold, but just right. Heat pumps are best just set up and left to run in a self regulating way.  Once the customer has got the settings right for them, the weather compensation controls mean that ‘the comfort factor’ can kick in.

Sometimes small features that we recommend are what attracts ‘exceeded expectation’ feedback. For example one customer said he didnt realise the difference a secondary return pump would make to deliver hot water instantly to his tap rather than the long, water wasting, time lag on a remote sink.

3. So, we could probably write a book about the confusion over some of the following areas but an interesting conversation we had was about what level of insulation you need to ensure a heat pump is going to be effective? Can you explain this a bit more to homeowners and do they have to meet Passivhaus standards?

This is a really interesting one, its really a matter of low hanging fruit’ and what is going to have the biggest effects in terms of improving energy efficiency or reducing heat loss. Id say number one priority is roof insulation and changing light bulbs to low energy options. For most houses it is not necessary to get anywhere near an EnerPHit or Passivhaus standards. If you consider wall insulation you need to also look at the air tightness and insulation qualities of all your windows and doors. We can provide some worked examples of the difference in heat requirement with different configurations of wall insulation or specification of windows.

Heat loss, even through solid walls, may not be as much as you might imagine. Its a balance of outlay for often quite invasive internal or external insulation. This type of retrofit also has to be carefully managed in terms of condensation. If you seal up then you may need to install mechanical ventilation to remove moisture, keep the house fresh, control your air changes, keep in your heat. I feel a lot of this needs to be approached with common sense and practicality and what are you going to benefit from most in terms of comfort, energy efficiency and carbon reduction.

As heating engineers we calculate heat losses. There are many myths about retrofitting heat pumps; that you need underfloor heating and that these systems dont work well in an older property. This is not true. We design a system for the heat losses that actually exist in the property. As long as the heat pump and heating emitters are designed to meet the needs of the property the homeowner will be cosy. There are a few properties where it is difficult to have a heat pump because the start up electricity demand is more than is available, so it is impractical. The barrier can be connecting a 3 phase electrical supply that can be prohibitively expensive.

It may be that installing a heat pump system is of higher priority than solid wall installation. Usually the driver would be an old faltering heating system, or a project underway where it would make sense to undertake radiator upgrades, if the radiators are also old and inefficient. Deciding to make the switch to renewable energy means your heating is 300% - 500% efficient (because it harnesses the Sun’s energy) and uses electricity to run which should be zero carbon in the future. However much you spend on wall insulation, new windows, doors, MVHR if you retain a fossil fuel heating system you wont be achieving the carbon reduction.  This is what motivates me assisting people to choose a lower carbon option. I would also recommend adding solar PV and battery storage onto a heat pump system to make running costs really low. Make sure youre on a tariff where you get electricity for a cheap rate during the night and charge up your batteries to run the heat pump and appliances during the day, even in the winter when the PV is not contributing much.

4. Can you tell us a bit about the innovations that have been made in ASHP's and what brands and/quality of product should a homeowner be looking for and the benefits of newer models?

The European market for heat pumps is so large, it is driving the technology improvements all the time. Some of the new NIBE (a Swedish brand) air source heat pumps are so efficient that they are able to run at 50 degrees celsius, which is quite a high temperature for a heat pump and still fulfils the efficiency criteria to be eligible for the "Boiler Upgrade Scheme" grant. At that temperature it is sometimes possible to not have to change all the radiators. If radiators are modern we would advise evaluating them on a room by room basis and switch them around if possible. One of the new innovations is the use of a new type of refrigerant within these heat pump units meaning that 10% less electricity is used.

It is important to dispel myths around the noise of air source heat pumps. High quality modern heat pumps are very quiet. Ive lived with a heat pump for 15yrs and we recently installed a new unit. Our previous unit was still working fine and we sold it on, but it is important to road testthe latest products on our own house. Our heat pump is positioned under our en-suite window and that is the window I have open in the summer. After showering I used to be able to hear the previous units fan running, but with this new heat pump I cant hear the unit running at all. One of the factors that make units quiet is the size of the fan, so if the heat pump unit is large this isnt a bad thing. I havent heard all of the other products running but I know that NIBE and Steibel Eltron are whisper quiet these days. 

5. Most women homeowners will often upgrade a boiler when undertaking a large renovation project and there is a lot of concern that all the radiators in the home will also need changing to much larger ones to allow for the output or a complete change to underfloor heating is needed? (UFH)? Can you clarify this for us?

There are two very important points here. New regulations have recently come into force that require any completely new heating system to be designed to work at a water temperature of 55 degrees. Bear in mind that gas and oil boilers traditionally run at a water temperature of up to 80 celsius. The reason behind this legislation is to push systems to be 30% lower in carbon emissions even if they are still using gas and oil to produce the heat.

The second point is air and ground source heat pumps should usually be designed at between 35 and 45 celsius flow temperature. This is where the radiator upgrades come in. It is common sense that a radiator that heated the room at 80 degrees will not heat the room if the water temperature is 45 degrees. It is very important to look at the quality of the existing radiators. Homeowners routinely have a new boiler but dont change their radiators, meaning the radiators are old and inefficient. I believe people should look more positively at being challenged by the move to lower water temperature heating to make genuine improvements to their whole system. I know it costs money but it is a good investment. 

Regarding the question of underfloor heating, I dont generally recommend retrofitting underfloor heating. In most situations the upheaval is considerably more than having new radiators. If you are having all your floors up then thats a different matter.There are lots of options for installing UFH but many of the clever pre-grooved boards are very expensive. Be wary of electric underfloor heating as this is expensive to run as it is of course direct electric and can only be 100% efficient.

I spoke to someone this morning who said shes been going around her house oversizingher radiators, as shes been decorating etc., in readiness for an air source heat pump in the future, which is a good tip.  You will need all the calculations to be done by a heating engineer. You could ask for a ‘heat pump ready’ size radiator to be fitted, this means effectively a radiator that has an output 3 times that of one that is working with a gas or oil boiler. The new radiator wont be physically 3 times the size on your wall and radiator technology is also moving forward.

6. What are the benefits of adding Solar PV to the home when installing an ASHP?

Getting into solar PV is ‘peace of mind’ particularly when partnered with battery storage. It gives the homeowner confidence that they are, to some degree, buffered from fluctuations in electricity prices. It is something you can have control over, even though you cant control gas or oil prices, you can generate and store electricity. With batteries, you can opt for an electricity tariff with cheap overnight prices and charge your batteries then for use during the day. This supports the running of the ASHP too. It is all a step towards the electrification of heating which is the best route to decarbonisation.

7. What is key to a successful process/plan when a homeowner is looking to upgrade their home and add an ASHP?

A top tip is get your heating contractor in early and think of the heating aspect of the project as embeddedin the property. It is an expensive part of the refurbishment, so it needs to be planned and scheduled in at the right time, particularly if you want pipework hidden. Remember water pipes cant just appear by magic, nor electrical wires. If it is a major renovation you need plumbing first fixthen builders and plasterers etc come in, then plumbing and heating second fix comes in.

If youre working with budgetary constraints, prioritise the heating over spend on a kitchen, for example, as the heating is really part of the infrastructure of the property.

8. What do you see as the biggest pitfalls for homeowners when adding an ASHP and any tips on avoiding these?

A pitfall is not knowing who to trust in terms of quotes from local MCS registered installers. Be very suspicious of a company that says you dont need to do any radiator upgrades. If youre switching from gas or oil and havent significantly upgraded your thermal efficiencies this is not likely to be correct. They may be taught to sell that way to get the sale. Consider hiring a local installer who can service your system every year. Ask about the length of warranty on the product, choose a product that has a seven year warranty ideally. Ask to speak to previous customers, as reputable installers should be able to provide live testimonials of their work. It is easier to work with one installer who offers plumbing and heating. Although you can ask the heat pump installer to come in as a specialist, you will need to be careful with your project management and co-ordinating the plumbing work and heating work, so it ties in seamlessly.

9. What do you think needs to be done to improve the uptake of ASHPs in the UK, knowing its the best option we have for reducing our carbon emissions?

Ive recommended that we need the incentive scheme currently in existence in Scotland in England! This means higher grants, as the current BUS £5000 is not enough. Also a game changer will be zero percent eco loans. They have had a raft of incentives and financial support in Europe for many years and there were 620,000 heat pumps installed in France last year. We also need electricity prices to be lowered, at the moment they are unfairly tied to gas prices. The government should be targeting both carrot and stick measures on the ‘off the gas grid’ areas. I believe that winding down the mains gas grid does need care to not cause an awful fuel povertyscenario but plans need to be put in place that are fair to homeowners and actually move forward towards carbon reduction targets to slow global warming.

10. What career job opportunities are there for women in your industry and what suggestions do you have for women exploring the right training and looking for the right opportunities?

There are certainly going to need to be many heat pump engineers trained. There is a new Low Carbon heating Technician apprenticeship about to be launched later this year. Essentially heat pump installers need the highest level of skill in the domestic heating industry with design and practical skills to plan and install complex pipework. I think there is a perception that somehow heat pump installation is nearer to clean techbut the work is usually on a building site. I believe there are many opportunities for M & E designers and Retrofit Assessors that might appeal.



Please feel free to contact Louise Howlett if you would like to discuss any upcoming projects. 


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