This is the second of three episodes that are looking at heating system solutions for Future Homes Standard homes.

To discuss air source and ground source heat pumps for individual dwellings, Chris is joined by:

• Hannah Rapson from Vistry
• Nick Houghton-Best from Daikin
• Neal Stone from Renewable Energy Domestic Design

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 episode is one of a set of three looking at heating system solutions for the future home standard.

This time we are looking at systems that many think will be most common. Air source and ground source heat pumps for individual dwellings.

We've got with us Hannah Rapson from vist, Nick Houghton Best from Daikin, who make heat pumps, and Neal Stone from Renewable Energy Domestic Design who offer design services for both heating and plumbing. I start with this fairly simple question. How are heat pumps different from gas boilers? I put that first to Hannah from vistry.

They're completely different really, aren't they? You've got to take into consideration how they work.

So gas boiler is burning a fuel at a high intensity to spread that warmth around your home and then got heat pumps which are extracting that heat from air or ground or another source to kind of compress it down into your heating system. So right from the get go of how they work, they're completely different to gas boilers right through to, well, how do we install them in homes?

You know, we've got to find internal spaces for plant because homes might have that added hot water cylinder, for example, that previous homes may not have. They've had a combi boiler or for example the rather large external unit in the garden. Where are we designing that in?

So it's really important to make sure we're accounting for that space where gas boilers are quite neat really. They've always kind of fit within a boiler housing in your kitchen or utility room. So from that kind of design stage, those are the big differences.

Obviously from a user perspective, we're going to have to manage that transition for our customers and set those expectations about how a heat pump is, is very different to a gas boiler. You don't come in and crank it up when you want to intensely heat your home.

It's more about running on a lower steady temperature to ensure that kind of consistent thermal comfort. So that managing of customer expectations is a learning curve for us all. But I'd say the major difference in terms of user experience for heat pumps.

And Nick, I know you've had background in the sector previously in the world of gas. I mean, how do you find it as someone who's involved as a supplier of manufactured heating sources? I guess I should call them.

Yeah, Hannah's right. The systems are quite different in how they operate.

The main difference I think we have to counter is that with all air source heat pumps we have to store water. Now when we look at the market historically of gas boilers, 75% of the market is combis that don't need a cylinder.

So we do know as we move to air source heat pumps and it's been one of the challenges with the house builders is have an airing cupboard that we can put a cylinder back in so we can have domestic hot water storage.

Other than that, I guess from a design point of view, you know, there's some unique things for an air source heat pump, but the homeowners that are using these new modern heat systems of the wet radiator systems and the hot water, they shouldn't really see any difference or performance difference moving to these all electric systems. And there are some unique benefits, I guess, energy security being probably one of them.

And then while the weather is so hot at the moment, there's also the benefits that there are some selected heat pumps out there that can also offer cooling as well.

And Neal, I guess is a good time to start talking about design. I mean, why do we need to treat heat pump system design differently from, from the way that we we've been managing with gas boilers in the past?

Well, just to add to what Hannah and Nick have said, yeah, they are got to be treated as completely different systems.

They have different design criteria, they have different requirements for the full system design and the way that they are actually sized physically as well. You cannot simply just look at a property and guess the size of the heat pump. You could do that with the combi boiler.

A gas system was a quick release, fast moving kind of system, high temperature, where you can put in different sizes of equipment and get away with it. You can't do that with a heat pump system.

So fundamentally it's the message that we've been pushing out through the future homes hub and personally for a long time in the industry is to basically say treat them as completely different. They look different, they operate different, they have to be designed completely differently as well.

And that design is way more crucial today than it would have been on gas because we are dealing with low temperatures.

As Hannah alluded to, we've got lower temperatures within the heating system, the emitters have got bigger to compensate for that lower system temperature. We have to think where they go. Nick mentioned about the cylinder. Every system's got a cylinder. We've got to know where that goes.

It's got to be a certain distance between the heat pump and the cylinder and we've got temperature differences. There within the system as well that we've got to think about. So there are way more things to think about.

But again, just to pick up on Nick's last point, fundamentally they're not different systems. It is a heat source supplying heat into a heating system.

Yes, we've got a cylinder involved in there, but we do large houses with boilers and cylinders. We've done that for many, many years.

Now that box that provides the heat is outside instead of inside and it's at a lower temperature to a gas fired boiler. So they are the so called differences. But there are.

We try and make it as simple as possible for the house owner so they're not frightened to death when they look at these new systems within their properties to say, whoa, that looks completely different. They'll open a cylinder cupboard and they'll see a cylinder. Nothing looks anything untoward in there.

It is the box, the heat source box that makes the difference.

Okay, Hannah, as a home builder, as a house builder, what are the things that you're having to think about in terms of the whole house when you're thinking of moving over to heat pumps? And I know you've done a lot of heat pump work already.

So it's a good opportunity as we look to that smaller scale adoption and learn those lessons as we scale up for future home standards. So we've learned the lessons that heat pumps are far more sensitive to poor design and installation and commissioning than traditional boilers.

We need to pay more attention to the actual heat loss of the dwelling, the fabric specification, emitter sizing, for example. So it's making sure we've got that competent design from the get go.

Also making sure that we're designing specifically from heat pumps from those early stages. So for future home standard, Vistry's designed the new Vistry collection to ensure that all that plant equipment is designed into the home.

And we're not trying to shoehorn it into an existing house type because we, you know, we want to make sure that there is room for all of that low carbon technology that's required to make the system run as it should. So making sure we've made those early design decisions is really important.

You know, there's good coordination required between our architects, between our SAP assessors, between our M and E designers, right through to coordinating the supply with our manufacturers, through to install with our site teams.

And, you know, it's not just about complying with requirements for future home standard or transition to low Carbon homes, but it's making sure that we are truly delivering those homes that are warm, they're efficient, they're quiet, they're easy to use and they're straightforward for the customer. So we need to think about how the customer or that end user is going to live with that system day to day.

So are there simple controls, are there clear room temperature expectations? Is hot water available when they want it? And just instilling confidence for our customers that the system's going to work as intended?

And are you finding that when you redesign the homes they're having to be basically larger?

Yeah, slightly larger.

I mean, they're getting larger with fabric specifications slightly as well, but making sure that we still have room for that plant equipment, but also not impacting negatively on storage space for customers. Because that's always a concern, isn't it? Make sure they've got adequate spaces.

Yeah, that's always the challenge, isn't it?

Yeah.

Making sure there's enough space in the cupboards.

Yeah. Where's my Christmas tree going?

And Nick, I mean, what are the other things that you're spotting that you think in terms of design that people need to be aware of, about it being different?

Yeah.

I've been lucky enough to work on both sides of the fence from design point of view, spending most of my career working on gas systems and designing them to be as energy efficient as they can for new build properties. But now, of course, on air source heat pump side, gas boilers are more forgiving. You know, reiterating what both Hannah and Neal have said there.

Gas boilers have got the ability to give us much more heat delivered than actually our homes need now that they've moved to modern design techniques and modern methods of construction.

Air source heat pumps need to be carefully designed to do with the outdoor placements and then specifically how it's going to install on the inside of the property, make sure it's sized correctly because they are more finite.

But as long as this is done, and I would say it's a pleasure to be working in the industry at the moment with house builders like Vistry and all the top house builders in the uk, because these are challenging times for us from a design point of view.

And it's been fantastic the way everyone has partnered together and communication has been fantastic from supply chain right the way through to designers, manufacturers and house builders, because we have designed these systems really well now and we've got a good structured way forward that we can scale up. And as long as we follow all of these steps, we can meet all of the demand that our homes and these modern heating systems need moving forward.

Okay, so I'm going to start off. I'm a developer, I need to get stuck into this. I mean, the advice from the hub is to identify a single responsible heating designer.

Neal, just to ask you about this design question. I mean, how do I find a single responsible heating designer?

I mean, I presumably ask Neal Stone, but I mean, you know, but where do you go if this is not a world you're familiar with?

Yeah, it is difficult because obviously we, yeah, there are, we're very good with the major house builders, like the vistories of this world and all of the other top sort of 20 builders there.

They have been looking at heat pumps for a significant amount of time and spent a lot of time and effort in trialing them and getting involved with designers like ourselves and manufacturers like Dakin to see their path and organize everything as they go through. And it's sort of a little bit like trial and error.

If we're talking about the small to medium sized builders, which is really where we're coming from with the future homes hub and giving advice out to people, then there are a couple of areas where you can go. Obviously there are independent designers like ourselves and others out there that people can try and find.

It is likely that builders and plumbers have used us in the gas world, so we would have provided designs on that front and then they're quite within their rights to contact us again to say, can you help us out, Neal, with my heat pump designs so we can do it that way.

The manufacturers are one of the best routes into this because obviously Fishtree, for example, will have used Ideal Valent, Baxi maybe on their boiler supply. Over the years they've all moved into the heat pump market.

So as a starting point, if you want to get some advice and therefore get a design, because all of those companies offer a free design service, then you can go down that route as well.

So manufacturers are good, I would say at the moment, probably the best route to finding a good responsible designer because they've all paired up either with good quality designers, indemnified designs coming back. So there's no worries with the plumbing contractors having any concerns over the information they get back.

So that is a, you know, the first port of call.

Then it's really just word of mouth, unfortunately, contacting the future homes hub, contacting plumbing contractors, get their advice, advice, even speaking to contemporaries. So we attend a lot of conferences, a lot of site visits, a lot of group visits to manufacturing facilities.

And the small builders mix with the large builders and they can ask questions. It's a very, very large industry, but everybody knows each other and that's the big thing about it.

That's true. You never know when you're going to meet them again.

Hannah, from your experience, what advice could you give to smaller developers on how you manage procurement in this new space?

Yeah. So from the design perspective for SMEs, the safe route is to go down the route of the manufacturer's in house design team.

Large builders might prefer to go down the route of appointing an independent third party just to ensure you've got standardized designs across all of the heat pumps you may use in your range. In terms of the wider procurement, I think you need to move away from thinking of it as a like to like swap from a gas boiler.

It's not just you're swapping a heat pump from a boiler, you need to procure that completely designed system. So you need to have the specifications clearly set out for those performance requirements from the beginning.

I'd also recommend having customer handover built into the procurement from the start as well. Daikin are very good at that.

Providing plain English user guides, having those agreed control settings, having homeowner demonstrations and aftercare support as well. Procurement isn't just about the material itself, the hardware itself coming into the home. It's from design through to customer care.

I mean we need to or whether you're a larger developer or an SME, you need to be engaging with your supply chain early. The manufacturers, designers, installers, merchants, just to test that availability, the lead times, training needs buildability.

I mean, our team recently visited a large heat pump manufacturer. It became evident just how much of a difference between heat pumps and boilers differ in terms of supply.

You know, fewer heat pumps are going to go on that truck that's delivering to site. You're going to need larger storage space as well. So all of those things need to get taken into account when you're procuring the product.

And we're always saying engage early. How early is early? Nick and Neal, what do you reckon? Nick first. When would you like that first conversation?

Yeah, so I guess from a build point of view, when we're talking about new build, we need to be at least 12 months in advance from when we buy land and put planning permissions in. From a design point of view, we're probably 12 months earlier than that. So theoretically you're two years ahead of your build.

Really from a design point of view, the good news is when we're Working with the big national developers, just like Anna from Vistry.

We've usually engage with them a long time before this because we'll do, and we'll design the whole entire house range through, through one system, through one of our design partners, come through the manufacturer.

That gives us as early indications we can do with any of the challenges that we can be addressed before we look at building that way, when work then starts later on, we've got a lot of that work done and it's more just about polishing off those designs before they get built.

Yeah, And Neal?

The design is much more critical now, as Hannah alluded to, in the whole overall process of the planning side for a site than it used to be. So we like to get involved right at the very early stage.

So when the planning is going in, they will have appointed a SAP or a HEM assessor at that point and we should be. We or our contemporaries or the manufacturer should be notified at that point as to which type of system is going in, which manufacturer.

And then they get SAP calculations and heating designs done at that original early stage, as early as possible. So you get that done.

And then as the process, the planning process goes through and as we start getting towards a start on site, we are changing things in real time as it's going along, because things do change. Heat pumps have to move positions on certain plots, maybe some equipment isn't available. We have to take that into account.

You cannot just simply swap one heat pump for another and expect everything to work. So you have to bear that in mind right at the very start. And then designers these days work the way through the site should be the way.

So any queries, any changes get notified back to the designer to see what the implications are. So the earliest possible engagement point should be the case. Really, the earlier the better.

Okay. And Nick, I just want to ask about the next stage a bit.

I mean, in your experience of dealing with lots of different developers, I mean, how do you think developers should manage the site installation and commissioning process? What do they need to be looking out for and how do you help them with that?

Yeah, I guess it goes back to the question you were asking Hannah before about the developers and the kind of procurement side, because there's a very careful sort of vetting process that goes on. Manufacturers making sure that they're all selected to be the suitable ones and all this merchant supply chain and all of that is kind of in place.

And that then starts very early with the design companies from Neal making sure that all of the technical attributes of that install have been carefully designed and documented so that when we do get to site and when we've got an install, that there's no ambiguity there and there's nobody making decisions on site for something that isn't already documented. You shouldn't be, we shouldn't be getting to that stage. There is training, of course, there's plenty of training centers all over the uk.

Most manufacturers will also have the facility to train installers on the site on live building sites, on live installations.

And I really think this does help them take that classroom work and the education they've got from those training sessions and then make it into a real life situation of training for them. And we call that assisted commissioning. So we try and do that.

So as well as being a part of the site, speaking to the sales staff, peeking to the other associated trades as well, I guess really what we're doing there as a whole industry working together is everyone is working together so that everybody, all of the trades are as comfortable as possible with this move to kind of modern heating systems.

And Nick, is that for when you're doing the training, Are you doing the training for installation companies or is it for individuals?

Yeah, historically it's been the business name that's been engaged with training centers and then they've had the accreditation for it.

A couple of years ago we modified that and we now train individuals, which has got two things which is really good, and we've taken this as lessons learned as we've done training.

One, people do leave businesses and move around and if the business is trained, you might have their new operatives that perhaps haven't been on the training and are installing heat pumps and maybe they haven't got all the guidance to all the questions that they need. So it stops that when we have individuals being trained. But from a good point of view as well, that training is then portable.

So if they're working for one contractor and they've been on the training course, they've got a certification with their name on it and a reference number. It means when they do start with that new business, they can take that then with them.

And this then, I think helps us make sure that everyone is well supported in the industry.

Okay, brilliant. And Hannah, anything to add from your side on site installation and managing that and what's changed for you at Vistry?

Yes, I think appointing a competent contractor is so key.

Somebody, as Nick said, who has attended the training courses offered by the manufacturers, not just one representative from the subcontractor that's appointed by the builder making sure that every person that's going to be working and installing heat pumps on that site has attended that course. To ensure that everybody is competent and that POS positively links to the warranty for the product as well.

I think site teams, they need to make sure they've got clear drawings and those installation details. They need checklists as well and clear responsibilities right before work starts, not just at the end of the build.

They need to make sure they've got those critical details for external unit positioning and those clearances, the condensate, drainage pipe insulation, for example, wiring controls. There are so many different components to make sure are installed correctly.

That's why there's such complex systems in terms of commissioning that needs to be treated as a key performance step in itself as well.

You know, making sure the flow rates have been set up correctly, the controller settings are set up correctly, the weather compensation as well, hot water settings and that customer ready handover information. So, you know, fishtree's a long way towards providing this information to our teams.

We've got best practice guides and checklists, site managers, for example. Of course, it's backed up by photographic evidence of key components as well.

But I think, you know, having these key steps is all pertinent to making sure the system is installed correctly and is going to work as intended.

You know, the customer transition is going to be smoother as well if those sales and customer care teams are brought in at the same time as the site teams to make sure we've got those consistent messages as well. Make sure you're avoiding constantly adjusting settings, just leaving them alone. Always joke.

We should have a do not touch sticker on all of the heating controls in the home. Making sure those controls are used as intended and understanding that lower flow temperatures don't mean that the home is underperforming.

Brilliant. Okay.

I mean, I suppose it's probably appropriate for me to say there's lots of information on the future Homes Hub website and my favorite being the site manager's poster, which I think my colleagues have done a great job with. I've got my one last question now. I like to pretend that I can grant wishes. I'm not going to grant you three wishes each.

I'm only going to grant you one wish each, which is what is the one thing you would like listeners to the podcast to take away from our session today? And I'm going to kick off with Neal, if I may.

The overriding view, purely from a design point of view, is that anybody wishing to install a heat print or looking that for the first time should try and engage a designer at that earliest possible time. And the best route to do that is to go through a manufacturer who you know and recognize or at least have had some sort of dealing with.

And so if anybody can just reach out and do that through the hub and really get that early engagement, don't be frightened of heat pumps, just engage with the designers. We all know what we're doing. The manufacturers and the designers all know we've done it for many, many years.

So yeah, just that very, very early engagement sort of route and you know what I would say is that designers as a whole are trying to find ways of getting that message out to the wider industry as to where people should go, you know, because it is difficult, it is a niche market. So I am in the process of having a little look at that.

So hopefully in the future I'll be able to do something through the and basically say, look, here's where you can get some good advice as a starting point. But that would be the main message, early engagement.

Thanks Neal. Nick, what's your one wish for us to take away?

Yeah, definitely agreeing with a lot of what Neal was saying. I guess there's a lot of information available. The Future Homes hub.

I've got a very unique approach to helping people and disseminating the information around heat pumps and getting rid of those myths as well.

So hopefully listening to information like this gives everyone confidence in embracing the move to modern heating systems so that we can all benefit from them, energy security and all the efficiency that it brings with these modern heating systems. So hopefully everyone's just more confident and able to embrace the new technology.

And Hannah, last word from yourself.

Well, I'm going to be greedy and have multi fold one wish designer easily.

I'm not saying that's allowed!

Design it early and specifically for heat pumps. It's not a direct swap as we have spoken about.

Appoint those competent installers and commission it properly and do not forget to bring the customer along on the journey because with the right installation, the right training confidence in the system and good aftercare, they're all important parts of this low carbon transition.

Well, I think that was such good advice. I'm going to let you off Hannah, so that's good. Anyway, so thank you so much. It's been a real pleasure having you. Thank you Hannah. Thank you Neal.

Thank you Nick for joining us on the Future Homes podcast today.

Thank you.

Thank you Chris.

Thanks for listening to this episode of the Future Homes podcast and thanks once again to Hannah.

Nick, and Neal, if you'd like to explore more of the topics we've discussed today, there's practical advice, news and events at the Future Homes on our dedicated Knowledge Center. Make sure to follow or subscribe to Future Homes wherever you're listening so you don't miss anything.

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