This episode is one of a set of three looking at heating options for Future Homes Standard homes.

We look at heating systems that work well with individual dwellings with especially low space heating demand.

This includes exhaust air heat pumps, direct electric heating, and heat pump cylinders.

Our guests are:

Peter McBride of Mixergy

Jerry Gorman of NIBE

Mark Lufkin from Wondrwall.

Linda Field from Qvantum UK.

Welcome to the Future Homes podcast where we look closely at the ideas, policies and practical challenges shaping how homes are being designed, built and delivered in the UK today. My name is Chris Gaze. This podcast is one of a set of three looking at heating solutions for Future Homes Standard homes.

Today we're looking at heating systems that are particularly appropriate for individual dwellings with especially low space heating demand. So we'll be considering exhaust air heat pumps and direct electric heating.

Direct electric heating will often be specified with a heat pump cylinder, so that's on the agenda too. Our guests for this One are Peter McBride of Mixergy, Jerry Gorman of NIBE, Mark Lufkin from Wondrwall, and Linda Field from Qvantum UK.

We're starting this time by asking each guest to share a quick introduction of their company and their offer. First up, here's Linda from Qvantum UK.

Hello, my name is Linda Field. I'm head of new build and social housing at Qvantum.

Qvantum are a Swedish heat pump manufacturer with a 30 year history building heat pumps that are easy to install, maintain and easy to operate.

Okay. And that makes it appropriate for me to go over to Jerry at NIBE and Jerry, tell us a little bit about NEBA and how you fit into the space.

Yeah, well, my name's Jerry Gorman. I'm national Sales Manager for new build at NIBE Energy Systems.

So our product portfolio includes ground source, air source, domestic hot water heat pumps. We also make heat interface units and exhaust air heat pumps system which I think we'll be covering off today.

Okay, thank you very much. And Mark Lufkin, tell us a little bit about Wondrwall.

Wondrwall provides a whole home energy solution for low carbon homes. Encompasses home automation, solar generation, energy storage and of course, heating and hot water.

What we're talking about today, historically we've offered infrared heating, but more recently we've also introduced a heat pump.

But regardless of what heating solution we put in place, the primary goal is to control the home in order to deliver the lowest possible energy bills.

Okay, great. And Peter, Hello.

Chris, Mixergy is a UK based clean technology company. We make hot water smarter, greener, more efficient and more affordable.

Brilliant. So we've got space heating side and the hot water side. I'm going to start off by asking a few questions about exhaust air heat pumps.

That's the sort of heat pump space that we're talking about today.

And Linda, I wanted to ask if you could tell us a little bit about exhaust air heat pumps and how do they work and what makes them different from other types of heat pumps that people might be more familiar with.

An exhaust air heat pump doesn't need an outside unit. I think that's probably what sets it apart from your standard air source heat pump, which most people are familiar with.

The way that it works is it draws the air from the warm, wet areas such as the bathrooms and kitchens, and it then uses that energy within the heat pump to provide the heating and domestic hot water. Obviously it's very efficient because it's using ambient air.

Now, some units are available with a thermal store, which means that residents can take advantage of off-peak tariffs and load shedding from their energy providers. And also some units can offer cooling down to 14 degrees.

This means that residents are obviously going to be more comfortable during the warmer months.

So you're essentially looking at one single unit that's providing your space, heating your domestic hot water and, and also your cooling just in one unit.

So. Hi Jerry, just wanted to ask you about when can I specify an exhaust air heat pump?

Because after all, there are choices of heat pumps and you make a whole range of them. So when would you be suggesting to people that exhaust air heat pumps are appropriate?

Yeah, well, I think, as Linda has very eloquently described there, where heat pumps come into their own. And if you have a flat with a balcony on it, a flat over a garage, you're going to need to site the heat pump somewhere.

So given that Future Homes Standard is ruling out gas Combi boilers, which would, a developer would normally just put that in a cupboard somewhere or in a kitchen unit.

Given that we now need to revert back to having hot water storage, a developer has to nominate a space for that.

So why not, as Linda says, combine all the other elements of the CMEV, the hot water cylinder, the heat pump module, and then have that in a very compact footprint of around about 600 millimeters square into a small cupboard. It lends itself, as Linda said, to flats, apartments and smaller houses.

And what's the sort of maximum load that they can cope with, Jerry?

I think ours will go up to 6 kilowatt heat demand and then it will also give you up to 3 kilowatt in cooling. So it's quite a broad spectrum, catering for properties up to around about 150 square meters, something like that.

You know, you clearly need to do the heat loss calculations and size the product accordingly to ensure that you've got the correct specification there for that property.

And because the heat source is the exhaust air, I mean, does that have an impact on the coefficient performance in comparison to say, an air source heat pump?

Yeah, definitely. And I think also, you know, you'd expect about just under 4 cop for that type of product.

You've also got the benefit of it being an R290 product, so you've got higher efficiencies there for developers that are keen on meeting sustainability goals with an R290 product, you've got a very low global warming potential there. So it's a super efficient product, always round. I think you've got AAA on heating, it's probably a triple A efficiency. So it's a very, very efficient.

And an R290 is the coolant that's in the heat pump?

The R290 is the refrigerant gas that is used in there.

Yeah.

So, you don't have any exclusion zones because it's minimal amount inside the unit and there are measures within the unit to evacuate that gas out through the vents if there is any escape. So it's super safe, super efficient, and in terms of installation, it's very, very easy to fit.

You just kind of wheel it into position, the connections are made, flow and returns, the incoming water and the hot water out. So it's very, very quick and easy fit, very simple.

Okay, brilliant. That's a bit about exhaust air heat pumps.

I want to ask Mark a couple of questions now about the Wondrwall system and I suppose particularly talking about your direct electric solutions. But as you said at the beginning, you're also doing heat pumps now as well.

Can you tell us about your direct electric solutions and how you know in particular about infrared and how that is different from conventional electric radiators and also about when can you specify direct electric in a Future Homes Standard property? Because that's presumably getting a bit more difficult.

You give me two questions there in one go, but let's go for it.

Sorry, Matt.

No problem. So let's just jump in with the heating system and particularly the infrared. So first of all, the similarities to direct electric heating panels.

So they're cheap, they're cheaper than the heat pump, they also last twice as long as a heat pump or a gas boiler for that matter. It's really easy to design them and really easy to install them. Any electrician can do the work. They don't need any specific annual maintenance.

So overall, lower cost upfront and lower lifetime costs. Where the infrared differs is that it's radiant heat. Radiant heat heats objects and people rather than the air primarily.

So to give an example, it's a bit like sunshine. Imagine you get up in the morning on holiday in Greece. You get up, the sun's shining, you feel warm in the sunshine.

During the day, that heat is absorbed by the buildings, tables, chairs, sand, whatever, and as the sun sets in the evening, they radiate that heat back.

So you get that combination of immediate warmth through the radiant capacity and also through the absorption, a form of storage heating effectively within the property.

The real benefit of that, that radiant panel is we can ceiling mount the panels so it gets them out of the way, frees up wall space, so you can really lay out your rooms as you want and you've got more usable space and you get better heat coverage. Given the panels are on the ceiling, you can put them where you need to and it gives you good heat coverage within the room so you don't get these cold spots and you get immediate heat coverage throughout the room.

The other benefit, and the specific reason we went with radiant rather than direct electric, has to do with our controls, which is we learn when rooms are occupied and when they're empty, and how quickly that room heats up and cools down. And then we build a schedule to have the room warm when it's occupied and let the temperature drop when it's not occupied.

We get roughly a 30% reduction in energy consumption through that. But where the radiant is important is, let's say somebody goes in when we expect that room to be empty. We need to get it back to heat quickly.

And that's where the radiant infrared panels come in.

They work particularly well with that form of control, which is rather different from a heat pump, which is a much stiff, lower heating system, to the second bit, which is the Future Homes Standard.

Yes. How do we specify them in the Future Homes Standard, then? How do they fit in when basically you've got a coefficient performance of one, haven't you?

Basically, yes, that's correct. They're 100% efficient, which I suppose is better than a gas boiler, but definitely not as good as a heat pump.

But you're right in your original comment, which is, yes, this is getting more difficult under the Future Homes Standard. So the way we used to do it is, is we would put the infrared panels in.

It would replace the incumbent heating system, as it were, and we could offset some of that loss of efficiency by putting more solar panels on the roof of the house. That's no longer possible. So now it comes back to really, the fabric has to improve.

So to offset the lower efficiency of the direct electric heating system, the fabric has to improve, and lower the heat loss such that you offset the greater efficiency of the heat pump in the notional spec.

Okay, no, well, thank you, that's really helpful.

And this is where I guess it's very appropriate for us to introduce Peter, to tell us a little bit about the hot water provision, particularly in those sorts of types of dwellings. Yeah, Peter, tell us a little bit about how you handle hot water and what makes Mixergy a bit different from many types of cylinders.

Okay, Chris, thank you. So the Mixergy cylinder is smart. We are able to volumetrically heat. So that's very unique to Mixergy technology.

With regards to the Mixergy IHP, we combine efficient heat pump hot water generation with smart controls.

So we have completely redesigned our heat pump cylinder so we have a modular design which means the head unit can come separately away from the cylinder. So that makes installation quicker and easier. That also enables us to be able to offer an enhanced warranty on, on the two units.

So we can have a warranty for the heat pump head and the warranty on the cylinder itself. Again, very differently to our incumbent products on the market.

We don't have a wraparound condenser, which essentially means that the reheat periods are anywhere between six, all the way up to maybe about eight hours. Mixergy is able to heat the quickest on the market and we can actually deliver usable hot water within 30 minutes.

So one real challenge we see with heat pump technologies and particularly heat pump cylinders, is because they have an internal unit which is often rated less than than 1 kilowatt, that then has a big impact on the reheat period. So you'll either find incumbent cylinders are massively oversized.

So as an example, you might have a two bed home which has a 250 litre cylinder, and that's because they want to basically try to heat up the whole cylinder, which then means you never run out, which obviously then means you're using more energy, which obviously has an impact on carbon and energy bills. Whereas with Mixergy, our range goes from 120 litres all the way up to 250.

So you can fit a cylinder that's more suitable for the application, knowing that it's going to warm up as quickly as possible.

And we can actually have, we have two modes, so we have full eco, which means we heat the whole cylinder as efficiently as possible and that's to get the best performance out of the heat pump itself. Or we have Boost, which basically means we can deliver usable hot water within 30 minutes.

Okay, great. We've had a few mentions of 'smart controls'.

I'd just like to go around the room and just ask about smart controls, but I'll start since I've already got you. Peter, I'll start with you.

How do you find smart controls impacting energy efficiency both in terms of energy modeling which might be in SAP or the new HEM, and also in real life where we might be getting more efficiency or we might be able to to run our homes a bit cheaper. So how do the smart controls work.

For you from a Mixergy perspective, we are able to understand the tariff that somebody may or may not be on.

So they might have access to a time-of-use tariff where for instance they may pay 7p a kilowatt hour from midnight to 7am as an example and then they may pay 28p kwh outside those time periods. If Mixergy's in there, it is able to understand their usage through machine learning.

It's then able to understand what tariff they have and is able to shift all of those reheat periods to the cheaper period that also tends to coincide with having the lowest carbon impact and obviously then a lower energy bill.

We're also able to do - so I've got a Mixergy system in my own house and because we're able to measure the state of charge in my home as an example, I have a 250 litre Mixergy and I'm often able to delay a reheat period because I can see I have a sufficient amount of state of charge today to then cover me for tomorrow. So I'm able to heat my cylinder from the lowest possible state of charge to try to gain the best efficiency out of my cylinder.

So that's just one example how Mixergy is able to load shift to ensure you have the cheapest possible energy bills and carbon impact. We also have built in solar PV generation as well.

So if you do have solar PV, instead of this going back to the grid where it's just going to create more, more constraints on the grid, the Mixergy system in there is able to absorb any of that excess and, and store it in your asset today, which then brings us on to demand side response.

So demand side response is where essentially we are producing more energy as a nation than we're actually using. So you have three options, you either use it, store it, or pay to turn it off.

So if you're on a dynamic tariff, instead of paying to turn these assets off, if you're on certain dynamic tariffs, you'll often get incentivised to use this energy when it's either very cheap or to the extent where you actually might even get paid for it. So Mixergy is able to understand that, and pulse, and turn it all on and off to suit.

Okay. And Mark, you know, the smart controls is the sort of, I guess is the heart of the Wondrwall proposition, isn't it really?

Tell us a little bit about them and how they work in practice for people?

I actually see it split into two different pieces. There's what you're referring to, which is energy efficiency. So that's the idea of reducing energy consumption.

So that would be something like what I was talking about before.

You don't waste energy heating up empty homes or empty spaces within the home, or what Mixergy does with only partially heating the hot water tank rather than heating the whole tank or even the SCOP, the COP of a heat pump, that's really about using, maybe not with a heat pump, but smart controls to reduce energy consumption.

The piece which I think is actually more important is using smart controls to reduce energy bills, which is more akin to what Peter was talking about.

So the goal then becomes, 'how do you control your heating but also your hot water and I suppose the other aspects of your home to reduce the energy bill as far as possible'. So for example, if the sun's shining, that's free electricity, Try and use that and store it within the home.

Store it as hot water, store it within the battery, store it as heat.

If there's insufficient solar generation, let's say it's a winter day, the days are shorter, there's a storm, then you import cheaper energy at off-peak times and store that within the home, again as heat or as hot water or within a battery. And if you have surplus solar electricity at peak times, you can go and push that out at peak times to increase your revenue bill.

And within the Wondrwall system, I mean, how important is it to have a battery? I mean, is it a requirement or is it just a nice-to-have?

That's a very good question. From a regulatory point of view. It's nice to have.

I personally would go and say that it's a bit of a nonsense to sit a load of solar panels onto the roof of a house and not put a battery on it, just because you're wasting an awful lot of that solar energy and it's potentially going to go and cause problems with too much generation during the peak times of the day, which the grid can't cope with.

But the other part of it is, yes, there are smart tariffs for heating and hot water, but the way the energy retailers compensate for those lower off-peak periods is by increasing the price of your day rate or your peak rate. So a lot of them have a higher day rate or a higher peak rate.

And the problem you have with your cooking, your washing, drying, watching TV and so on is it's quite hard to shift.

So although you may make a saving on your heating and hot water by doing those at off-peak times, that offset by an increase in your running costs through the peak times for all of your cooking, washing, heating and so on. Now, I know SAP doesn't care about it too much because it's unregulated energy, but from the point of view of a consumer, that's a real annoyance.

Your energy bills end up going up.

The only real way to mitigate it is a battery which is either going to store solar for later use during those peak times or allows you to save off-peak energy to use during those off-peak times.

So even though you can use time reduced tariffs with heating and hot water, and I would strongly encourage that, I think it needs to be coupled with a battery to give the full benefits and pass on full savings to the consumers and the homeowners.

Okay, thank you. Now Linda, what's the role of smart controls with exhaust air heat pumps?

Well, at Qvantum, we have quite a lot of smart technology within the units. We have the thermal store as opposed to an ordinary cylinder inside.

So that means that you can charge your thermal store during off-peak times, which means obviously the end user is taking advantage of cheaper rate electricity and then that energy can be discharged during peak times, not only giving the end user savings from a cost perspective, but we are also flattening the curve of the national grid energy use because as I say, we're working it in reverse.

So again, the end user can get on the most suitable tariff and if they are load shedding, because we're very good at getting green energy within the UK, what we're not so good at doing is storing it.

So a lot of the energy providers do say, you know, would you like a free hour's electricity etc the end user can then take advantage of that because we have an immersion heater within our thermal store, so that can actually heat up to there. We've also got remote monitoring as well, which is very useful.

So that means that you can see if there is anything wrong with the unit. If there is anything wrong with the unit that can actually then be addressed, actually before an engineer gets there, because they'll know what's wrong with the product.

Okay, thank you. And Jerry, yes, how do smart controls work with your products?

Yeah, I mean, I think Neva, like the rest of the businesses we've talked about, are embracing this technology. And in fact, in Sweden, energy prices shift every half hour.

So, as a Swedish company, it's something that we're very aware of and they're kind of way ahead of the curve in Sweden on this. So it's very much part of our product. Smart grid capacities built into the unit, as well as the AI and machine learning to increase the efficiencies.

And I think we've proved that by using that, you can reduce running costs by between 18 and 20%. Exhaust air heat pumps are also compatible with PV integration, which is good.

And then if you need to carry out a Legionella cycle, for instance, at the cheapest rate, then the machine will learn when that is and tune into that. And then being able to monitor the running costs as well is as important.

So I think we're all doing the same thing in different ways, really. So it's all to reduce running costs and increase efficiencies.

Okay, that's brilliant. I'm going to ask one last question. This is the point where I like to, I like to grant wishes, as if I actually have any power to grant wishes.

But you don't get three wishes. You only get one wish each, I'm afraid.

And so I thought I'd start with you, Jerry, but what's the one thing that you would like folk to take away from today's podcast?

I think what you're doing, Chris, is fantastic. It's just sharing the knowledge for the industry.

Let's, you know, get our brands out there and offer ourselves as a font of knowledge or a school of education. So let's pick up with those SMEs and developers and have some conversations.

Okay. And Mark, what's the one thing you'd like us, like everyone, to take away from the podcast?

Yeah, I think it would be to go and look at that fabric. I know that the notional spec for the Future Homes Standard is heat pump plus a specific specification.

But as I said earlier, you know, there's the combination of better fabric plus direct electric heating actually gives a lot of benefits.

The same benefits from a heating perspective, but also gives cost benefit in terms of install complexity, cost to supply, cost to maintain, cost to replace over time the equipment.

So the notional spec is guidance, but there's a lot to be said for that combination of fabric plus a different direct electric heating system in terms of reducing complexity and reducing cost.

Okay, thanks Mark, and Linda, what's the one thing you'd like us to all take away?

I think very much as Jerry said, there are a lot of options for developers on the market, but there's also a lot of people that are willing to talk to and willing to help them with the journey to decarbonisation because there's a lot of information out there, but it's quite difficult to wade through it sometimes. So I think I would like people to take away:

"don't be afraid to reach out and ask for assistance, even if it's something that you don't think is possibly a product that you're going to use". Let's explore it so you've got the information to make an informed decision.

Okay, and I'm going to leave the last word to hot water. And Peter, what's the one thing you'd like us to take away, Peter?

I think for me, Chris, people need to understand that hot water, and particularly smart hot water, is a low carbon energy asset for the home. I would encourage people to look beyond notional building.

And what I mean by that is, you know, we're now stipulating that homes need to have solar pv, which is great. However, we've got data that proves a vast majority of that energy will just go back to the grid and people will have no real benefit.

So this is where it comes into - Mark mentioned earlier - batteries, you know. Smart hot water cylinders with a solar PV diverter is again another form of storage.

And there is upcoming legislation in the not so distant future where we need to have smart, flexible assets within our homes to truly take advantage of low carbon technology and low energy prices when it's available.

So I would encourage people to look beyond just putting some solar panels on the roof with, should we say normal solutions and look a little bit further with regards to smart energy assets.

That's brilliant. Thank you so much. That's been really interesting, so informative. Thank you to Jerry, Linda, Peter and Mark.

Thanks for listening to this episode of the Future Homes podcast and thanks once again to Peter, Jerry, Mark and Linda.

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