Psi and Y-values: What are they and why are they important?

We’ve created a short video that explains Y and Psi values and their importance when considering the thermal efficiency of your building. The video is on on the Kingspan Potton YouTube channel but I’ve embedded it below so you can watch it here:

EcoBuild, Earls Court – March 2010

We took Kingspan Vantage to Ecobuild back at the beginning of this month. We held a drinks reception on the Tuesday afternoon for all the Affordable Housing Partners that we’d presented the system to since last summer. With a selection of White and Red on offer it appeared to be quite a success.

Some of the press came along too, we’re hoping for some good coverage off the back of it.

Not part of Kingspan Vantage, but still a Kingspan Potton offering to the affordable housing market, were also a couple of partners with more highly architecturally led designs. More details to follow soon, but if you’re really keen, there’s a video of one of the designs below.

Photograph of the sofas on the Kingspan Potton stand at Ecobuild that were in so much demand

The stand was quite busy for the duration of the show, but the inclusion of sofas was a stroke of genius. We even had the UKTFA using our stand for a couple of their media briefings – which is cool because after all we’re members.

Ahem… sorry, not been here for a while

Not been here for a while, sorry, but I have been busy, honest.

We’re taking Kingspan Vantage to Ecobuild at Earls Court. The exhibition runs from the 2nd till the 4th of March.

Concept of Kingspan Potton stand at Ecobuild 2010

Above is a concept of the stand, it’s not exactly how it’s going to look, but it’s not a million miles off either.

We’re having some partners on the stand too. We’re launching some new architecturally led affordable housing solutions. I’m not going to post the details here until after the exhibition, but it’ll be worth waiting for.

We’re also being joined on the stand by HTA Architects who are the guys behind the Hanham Hall project in Bristol, where they are building 200 net-zero-carbon homes.

Come along and say hello.

Are we all destined for Fuel Poverty?

BBC NEWS | Business | Fear of steep energy bill rises.

–extract–
Domestic UK energy bills could rise by 60% by 2016 in a worst-case scenario identified by the energy regulator.
–extract–

This is staggering. I suppose at least with an energy efficient Kingspan Vantage house the fuel demand is lower, lessening the impact. Even if we halved the energy demand on a house we build today (compared to one that just complied with the Building Regs), then the fuel bill could still be higher in just six years time than one that had been built to current standards – by the way, Kingspan Vantage houses all exceed current Building Regulation thermal standards as a result of their design.

With rises of this magnitude possible, the return on investment on extra energy efficient measures is going to be very quick indeed. This I suppose makes my last blog about fabric first measures even more relevant.

Let us hope that the 60% potential is never realised **fingers crossed** otherwise we could all be in fuel poverty!

Fabric first…

If you look at successful energy efficient-buildings, whilst they might have vastly different aesthetics, they have in common one essential element: that is, they have been designed to minimise the energy required to heat or cool the habitable space.

This approach makes logical sense. Car design also follows this strategy; keep the weight down with good aerodynamics and then fit a fuel efficient engine to maximise the miles per gallon figures. At a very simple level good practice in energy efficient building design means that you; insulate the building effectively, keep unwanted air-leakage to a minimum and fit a fuel efficient heating/cooling system to deliver maximum comfort with minimum running costs.

Considering the car analogy again; if you made a heavy car with poor aerodynamics common sense tells you that a small fuel efficient engine is going to struggle to deliver the required power to move the vehicle as well as respectable miles per gallon data.

So, why do we think it is okay for buildings to be built with little insulation, extensive cold bridging and details that don’t promote air-tight construction, and then look to provide the energy for heating/cooling using renewable technologies? Renewable technologies that have a shorter lifespan than the building so will need replacing, probably several times during the life of the building. In complete contrast, investing in the energy efficiency of the building fabric will continue to pay-back for the lifetime of the building.

Even if the energy is ‘free’, let’s say as the result of a photo-voltaic panel, is it responsible to allow it to be wasted?

It is possible to design a house with Building Regulations levels of thermal performance and then look to bolt on renewable technologies, say and air source heat pump (ASHP), to achieve a Code for Sustainable Homes rating of level 3 (Ene 1). It is widely accepted that when there is a high differential between the external and internal temperatures the air-source heat pump is less efficient, so when it’s less than 5 degrees outside and the house temperature is also 5 degrees the pump is likely to be quite efficient, but as the house warms, and the temperature difference increases, the efficiency of the heat pump will fall.

If the house is thermally poor then the heat that the ASHP is creating will simply be lost. In a thermally efficient house more of the generated heat is retained. I’m not having a go at ASHPs, just the philosophy behind their use in in-efficient buildings. In defence of the heat pump industry, they promote the systems on their use in thermally efficient buildings. Download the Heat Pump Data document from the Heat Pump Association website – here.

If you opt for the Building Regulations standard of thermal performance and bolt on an ASHP then it, the heat pump, is going to need to be larger and therefore more expensive than one that will be required for a thermally more efficient building.

Oh… and let’s not forget that the ASHP requires an energy source for its operation – normally mains electricity, so if it’s running at low-efficiency then it’s using more electricity and therefore responsible for more CO2. And, if the pump isn’t delivering enough heat to the property then a secondary heating system is going to be ulitilised – this will further increase the energy use and therefore CO2.

I think this ‘fabric first’ approach of making the building efficient before looking at heating and cooling systems is also the reason why in the past twelve months interest in the PassivHaus standard has increased considerably.

Basic PassivHaus Principles (taken from PassivHaus website):
A dwelling which achieves the PassivHaus standard typically includes:
• very good levels of insulation with minimal thermal bridges;
• well thought out utilisation of solar and internal gains;
• excellent level of air-tightness; and
• good indoor air quality, provided by a whole house mechanical ventilation system with highly efficient heat recovery.

Maybe PassivHaus should be parked for a future blog.

Remember – fabric first! The building should be as efficient as possible before you look at what renewable may or may not be required.

Why am I telling you this? Well, it’s just that this is the philosophy that Kingspan Vantage designs follow.

Spread the word…

Kingspan Vantage – Updated Introduction Presentation

Updated version of the introduction presentation to reflect the new logo.

Updated Logo

Well, here’s the thing… The Kingspan Vantage literature is currently being typeset. The agency doing the work needed to redraw the Kingspan Vantage logo for the literature and they suggested some alternatives.

We had a sales meeting yesterday and unanimously agreed that one of the four that had been suggested was better than the one that we had.

This is it:

…and so begins the job of replacing the logo from everywhere it appears.

Heart of Vantage

As mentioned a couple of times in previous blogs, Kingspan Vantage makes effective use of the Kingspan TEK^® Building System.

In my mind the Vantage system has two core elements; the all encompassing design of the platforms and the system that is used to build the properties. These two elements combine to deliver a performance that is greater than the sum of the two parts.

The Kingspan TEK^® Building System is a SIPs based system (Structurally Insulated Panels).

What are SIPs?
Structurally insulated panels (or structural insulating panels) are a composite building material. They consist of a sandwich of two layers of structural board with an insulating layer of insulation in between. The board used in the Kingspan TEK panel is 15 mm oriented strand board (OSB/3) and the insulation is 112 mm of high performance CFC/HCFC-free rigid urethane. The Kingspan TEK panels provide the structure of the building as well as the insulation.

Unique Jointing System
The Kingspan TEK^® Building System utilises a unique jointing system that offer the building superior levels of air-tightness and significantly reduces the impact of cold bridging – see thermal performance blog. The system uses a thinner section cassette as a spline to connect the full size panels. The full size panels have their insulation routed to accommodate the connection cassette. As you can see from the image to the right, there is a continuous layer of insulation.

This jointing detail not only reduces the cold bridging but also offers a structure that has very low levels of unwanted air-leakage.

Thermal Performance
The 112 mm of high performance CFC/HCFC-free rigid urethane insulation used in the Kingspan TEK^® Building System has a thermal conductivity of 0.023 W/m^.K.

Sustainability
Environmental benefits in-use are realised as a result of the high thermal performance offered by the Kingspan TEK^® Building System i.e. the use of the system will reduce the energy demands for the building and therefore reduce CO₂ emissions.

Rather than hide behind the energy saving figures, Kingspan has had the manufacturing data for the system analysed by BRE and had a LCA (Life Cycle Assessment) produced.

LCA essentially ring fences the manufacturing process, including transportation of the raw materials and finished product, and arrives at a number of ecopoints per metre squared of material – based on the environmental impact of all the materials and energy use.

This is fine if you are comparing two identical products with exactly the same performance characteristics, but not so good when they don’t. For example, let’s say you had an ecopoints score of 10 for a candle, but another candle that appeared to do the same job, that is provide light, had an ecopoints score of 12. On the face of it, the preferred environmental choice would be the 10 ecopoint variant. But… what you didn’t know was that the 12 ecopoint candle actually doubled up as an air-freshener.

The same is true of construction products, some like the Kingspan TEK^® Building System offer insulation and structure, some just insulation, some just structure. BRE have thought of this and provide ratings for complete building elements e.g. the section of whole wall rather than the individual products.

In the case of the Kingspan TEK^® Building System, BRE assessed six walls and five roofs. BRE gave the constructions ratings of A and A+. Full details of the constructions etc… can be found in the Kingspan TEK^® Building System literature which can be downloaded from here.

Modern Methods of Construction
The Kingspan TEK panels are delivered to site pre-processed i.e. they’ve been cut to size, marked up and routed accordingly. This reduces the time spent on-site as the panels can be erected quicker than traditional build methods.

Certification
The System has full BBA certification. Other SIPs systems on the market that have BBA certification may only have product approval.

Kingspan Off-Site (manufacturers of TEK) has all the other badges as well, ISO 9001, 14001, Chain of Custody, Investors in People… but you’d expect that… wouldn’t you?

Thermal Performance

I thought it best to write about thermal performance, given that I’ve repeatedly mentioned the fact that the Kingspan Vantage system is energy efficient. If you’re already using the Vantage system, you don’t have to read this if you don’t want, because the thermal performance has already been taken care of; it’s designed in.

Let’s start at the beginning; why is thermal performance in housing so important? The energy category of the Government’s Code for Sustainable Homes has a mandatory requirement regarding improvements in the predicted rate of carbon dioxide (CO₂) emissions over the Building Regulation’s Approved Document L1A ‘Conservation of fuel and power in new dwellings – Apr 2006’. An improvement of 25% is required for Code level 3 and 44% for Code level 4.

CO₂ is produced as a by product of energy generation, typically from the burning of fossil fuels. The amount of CO₂ theoretically emitted by the completed property is calculated by working out the energy required to run the property; that is the energy used for heating, ventilation, hot water and internal lighting based on a standard pre-determined pattern of occupancy.

So…what’s the best way to achieve the required improvement in CO₂ emissions? That is easy, reduce the demand for energy.

Below is a pie chart that shows typically where our homes (UK) use their energy.

You can see that nearly 60% of the energy we use is for space heating. It therefore makes sense for us to look at measures to reduce the energy required to heat our buildings.

On the face of it, it’s simple, increase the insulation levels to stop the heat from escaping, except, it’s not quite that easy. You could just bolt on lots of insulation, but if the property has been poorly designed, detailed and constructed you will lose the heat through unwanted air-leakage and cold-bridging.

Let’s give you an extreme example of unwanted air-leakage – a chimney. If your house is insulated to the highest standard but you had an open chimney, most of the heat you have managed to prevent from escaping, as a result of your wonderfully insulated walls, floors and roof would simply disappear up the stack.

Whilst you may not have a chimney, the principle is the same, if the detailing around the junctions of the floors and walls, around the walls and roofs and even around windows and doors isn’t robust then the heat will escape, maybe not as much as the chimney however 🙂

What is a cold bridge? It’s where a material of lesser thermal performance interrupts another material for the width of the building element.

© http://www.flickr.com/people/27624393@N08/

I’ve not explained that very well, how about this: If you look at the photo above, you can see some blockwork. A lightweight concrete block has a thermal conductivity of 0.11 W/m^.K (the lower the figure the better). Surrounding the block is mortar – this has a thermal conductivity of 1.73 W/m^.K. The mortar has a much worse thermal conductivity and therefore is a cold bridge.

For the sake of balance, cold-bridging is not something that only occurs in masonry construction. Consider an oak framed building. If the insulation sits between the framework of the oak then the oak is the cold bridge as it has a significantly worse thermal conductivity than the insulation.

Now that I’ve explained what a cold bridge is and discussed a little about unwanted air-leakage hopefully it’s clear that what you actually need is a balance of improved levels of insulation and good detailing.

In the UK we use U-values to communicate the thermal performance of our walls, floors, roofs, windows and doors. A U-value is the inverse aggregate of the r-values (thickness in metres divided by thermal conductivity) of the components used in the construction – sorry… see image below for a simpler description.

 

Now the sales bit

The Kingspan Vantage collection uses the Kingspan TEK^® Building System for its insulation and structure. The Kingspan TEK^® Building System is a high performance SIPs system and offers excellent levels of thermal performance (the thermal conductivity of the insulation core is 0.023 W/m^.K – that’s 378% better than the figure for the concrete block!). 

Depending upon the performance of the cladding a standard Kingspan TEK standard panel will give your wall a U-value of around 0.20 W/m^2.K which is more than capable of delivering you a Code level 3 property. To make achieving higher levels of the Code easy simply supplement the standard panel with extra insulation; adding 20 mm extra insulation improves the U-value to 0.15 W/m^2.K.

I’ll blog more about the TEK system in the future, but for now you just need to know that if you chose Kingspan Vantage and Kingspan TEK thermal bridging isn’t really an issue. In addition, the construction details used with the system can deliver really low levels of unwanted air-leakage.

The Kingspan TEK^® Building System, used in Vantage, is performs so well that Kingspan used it to build the first Code level 6 house in the UK, the Kingspan Lighthouse and Barratt are using the system to build their 200 Code level 6 homes at Hanham Hall in Bristol. There’s a good video that talks about the Lighthouse on the Kingspan Off-Site website.

I’m also conscious of the fact that I’ve not delved into the topic of renewable energy – this too is likely to be a topic for a future blog.

So much to say… I hope I haven’t confused you too much.

Oh, and if you’re using the Kingspan Vantage system, don’t worry about everything above, it’s already designed in…

What is Kingspan Vantage – a short presentation

I tweeted this the other day, but thought it would be worth posting in the blog too. It’s a short online presentation that explains what Kingspan Vantage is.