Insulationzzz

As the weather starts to turn and it becomes pretty cold during the day (rather than just at night) it’s time to talk about insulation.

For me this is probably the least interesting of all the subjects I’ll be covering in my quest for the energy efficient sustainable house. But it is also one of the most important as insulation can be the most cost effective way of making the biggest difference to your energy consumption (and therefore your bills).

As far as I can tell there is a type of insulation for all the different surfaces of your house. So roof / loft insulation, wall insulation, and floor insulation. Each type of insulation has different products available depending on your house and your requirements.

Roof Insulation
This comes in different types, but the most common and easiest to install (you can do it yourself) is blanket loft insulation that comes in big rolls. The important thing is to make sure it’s 270mm thick. It can be placed in between joists and then another layer can be placed on top.

Otherwise if you’ve got a funny shape loft with hard to access areas you can get loose fill loft insulation (again you can do it yourself). This is loose material that you spread out. It’s recommended to use 200 litres per square metre to a depth of 200mm (20cm).

Or you can get blown fibre loft insulation, which is similar, but needs to be professionally installed.

Finally there is sheet loft insulation, which is for the sloping sides of roofs and can be placed between the roof rafters and then covered in plasterboard. I think this is especially good if you are converting the loft into an extra room and are concerned about the loft losing heat and not just keeping it trapped in the rest of the house.

Wall Insulation
The kind of wall insulation you get depends on the kind of walls you have. Newer houses tend to have cavity walls, so the wall is made of two layers of bricks with a gap or ‘cavity’ in between. In this case you can get cavity wall insulation which is cheap and effective. They drill a hole into the cavity and blow the insulation in then fill up the hole afterwards.

If you have an older house then they might have solid walls (they were built like this up until the 1930s). In which case you are unlucky, as there are two types of insulation available to you but they are both far more expensive and labour intensive to install. You can get internal or external wall insulation. The external insulation is insulating cladding that can change the look of your house on the outside, but can be more effective than internal insulation which can leave gaps where internal walls meet the outer walls. The internal insulation is insulated dry lining which would need to be applied internally to the outer walls.

Basically if you have solid walls you should hope you have a terraced house as it cuts the number of walls to worry about by half (as long as you don’t mind sharing heat with your neighbours).

Other wall types like timber frames can effectively be treated as solid walls.

Floor Insulation
Floors either tend to be concrete or raised timber flooring. For concrete you can lay a damp-proof membrane, then rigid insulation on top, then cover with chipboard plus your desired floor covering. For raised timber flooring you can lay mineral insulation in between the joists in much the same way as you would with blanket loft insulation (mentioned above).

Finally for both types of flooring you can buy some sealant to fill in any gaps between the floor and the skirting board where heat may be escaping.

If your house is over two floors you don’t need to insulate the floor of the upper level, as long as the space below is heated (i.e. a living room). If the space below is not heated (like a garage) then it is worth putting in insulation in the floor of the room above.

That about covers it for insulation! Or at least it’s as much as I can stomach researching it until we have a house and know what kind we’ll need.

And on that note, we have had an offer accepted on a house! Things are still in the earliest stages, but watch this space. Relevant to this post, I think the house has solid walls, so insulating them will be expensive… Also floor insulation has been recommended, as you can see on the EPC snippet below.

My next blog post is likely to be on boilers. Like insulation this was not a subject I was particularly interested in until recently when ours stopped working and I had to have freezing cold showers for a couple of days…

NB: the girlfriend is not fully satisfied with this post as it doesn’t cover the environmental impact of the different insulating materials, or air flow and insulation / double glazing with regards to damp proofing. But never fear, I will broach these topics when I revisit insulation once we have our futurefitting house (oh joy).

(Solar) efficiency isn’t everything?

To be a truly sustainable, energy independent, energy efficient house I need some way to generate my own electricity. At the moment I can only see two viable options (although I’m open to suggestions!), photovoltaic (PV) solar panels and/or a micro wind turbine.

I was leaning toward trying to do both, but my spirirts were dampened slightly when I learnt how poorly the turbine at 3 acorns had been performing.

So despite the fact that the UK has been on ‘amber alert’ this weekend due to the ‘near gale force’ winds of the storm called St Jude, I think I’m going to have to put my trust in solar panels for the majority of my electricity generation.

I’ve been looking in to solar panels quite a lot recently, and there’s a lot of information out there regarding thin-film solar, mono-crystalline and poly-crystalline, etc.

It seems the important figure to pay attention to is solar module (panel) efficiency (different to the solar cell efficiency, which is a bit higher). The efficiency is how much of the sun’s energy gets converted in to electricity.

At the time of writing this, the most efficient solar panel is SunPower’s X-Series that is 21.5% efficient. If you’ve only just started reading up on solar panels, this seems like a fairly low number, but the thing to bear in mind is that theoretically the most efficient solar panel we can ever produce will only achieve 44% efficiency (as only a certain range of light within the spectrum is used in PV).

Of course you’ll see news stories of record breaking solar cells of 44.7% efficiency, but these are CPV, or Concentrated Photovoltaic cells that use a concentrator to effectively shine more than 1 sun’s worth of light on to the panels. So it’s not quite the same.

Sounds good right? Sign me up, I’ll take some solar panels and a concentrator please. But unfortunately they aren’t available for residential use, and the cost is prohibitive anyway.

But it’s not important. 21.5% is more than good enough for most people’s uses. Even 15% is good enough to make a real difference. And people are very good at pointing out that you shouldn’t be an efficiency snob.

I don’t think I’m an efficiency snob, but what does concern me is a slightly different issue. It seems like advances in PV technology are happening every week. And the price of solar panels is decreasing all the time. I worry that I’ll get some solar panels and then 6 months later there will be residential panels available for half the price that are an extra 10% more efficient.

Just in the last 2 weeks I’ve seen the following stories which always make me think in a few months to a year solar panel efficiency is just going to leap forward massively:

A quarter more efficient?

A potential breakthrough in efficiency? (and good news for LED lighting)

And a possible 80% efficiency?!

Of course this talk of efficiency may be irrelevant to me when the time comes and we've actually bought our house. You also need to pay attention to positioning. A south facing roof is ideal (south-west and south-east are fine too). You can put them on roofs facing other directions too, but you lose efficiency (about 15-20% for west or east. I think it’s far worse for north).

And then there’s the angle of your roof too. A 35 degree angle is ideal in London, but the optimum angle changes depending on where you are in the world (or even just the UK).

So I’m not an efficiency snob, I’m really not. But depending on what house we end up with, I might end up having quite an unsuitable roof to place my panels on, so every percentage of efficiency may count!

Lessons in LED lighting

I’ve been trying to write this post for a few weeks now but work has been so busy.

I thought a post about LED lighting would be a good way to ease in to looking at energy efficiency. It’s one of the cheapest and quickest ways to make a difference in your energy usage. However if you don’t know anything about lightbulbs other than how to change one, it can be slightly confusing at first.

So what prompted me to look in to lighting was a combination of two events. 1: my girlfriend Anne bought a new LED bulb for her bedside lamp from Tesco, and 2: I saw this buyers guide on twitter.

I knew there were different types of light bulb and that LEDs are the new efficiency kings, but beyond that my knowledge was pretty basic. Also I could never remember what CFL stood for or what it looked like. So after looking around I made my own quick guide to remind me:

Really the important thing to note is that the more efficient a bulb is, the less electricity it will use (in Watts) to produce the same amount of light (measured in Lumens).

So for instance, the LED mini globe Anne bought is 4W and 250lm. It says on the box that the equivalent conventional bulb is 25W. I’m not sure what ‘conventional bulb’ means. Whether it’s incandescent, or CFL (which are now pretty common that I’d almost call them conventional). But anyway, that’s potentially a change from 25W to 4W (I’m not sure what kind of bulb she replaced). If you were to do this with every bulb in your house that’s quite a saving. You could cut the electricity use in your house (on lighting) to less than a fifth of what you are using currently (although this is likely a big exaggeration if you are already using CFL bulbs).

The other benefits of LED lighting is the bulbs last for a very long time (25 years if used for an average of 2.7 hours per day, the Tesco packet says). Also LED lights produce hardly any heat as a by product of creating light, so they don’t get hot to the touch. And they don’t have a ‘warm up’ period like CFL bulbs, where you have to wait for them to reach their full brightness once you turn them on.

The downside? They are quite expensive. Buying a lot of LED bulbs is not cheap. But you can easily earn your money back in the savings on your energy bill over the years. Also as LED light become more ubiquitous the price will come down (If they’re selling them in Tesco that’s a good sign!).

So having been totally sold on the use of LED lights I’ve decided I’m going to replace every bulb in our new house as soon as we move in. I was so enthusiastic that I pestered Ecotopia on their range of LED lighting (among other things…). As previously mentioned I am slightly obsessed with Ecotricity, and as I already use Ecotopia I was keen to get them to stock the bulbs I was anticipating needing.

They will be getting some in stock, but in the meantime I found a good range on Nigel's Eco Store.

The other thing to take in to account though is that LED light can come in different ‘shades’ of white. The names vary depending on what website you’re looking on, but you can choose from ‘warm white’ ‘pure white’ or ‘cool white’. Which basically means a orange tinge, white, or a blue tinge. This depends on the Kelvin number. I won’t go into this in further detail though, more can be found here.

Also I read that the Wattage needed for a room is the square footage of a room multiplied by 1.5. So for a room 10 foot by 10 foot (100 feet) you would need 150W of lighting. Again I assume this is for incandescent bulbs. So using LED lighting you need the equivalent, which is about 30W.

I don’t think I’m actually going to worry about the Kelvin of my light, or the Wattage needed yet though until there are actually some real life rooms to apply my newfound knowledge to.

Although while reading up on bulbs I did come across this kickstarter, the Nanolight!

It had already been funded by the time I’d seen it, otherwise I probably would have backed it to get myself a Nanolight. I can see they’ve rebranded now to nanoleaf so maybe I’ll revisit their site when the time comes.

And finally. If anyone is looking to switch energy suppliers to Ecotricity (which I can highly recommend) if you quote this referral code ( RAFE-4WKE5 ) when making the switch, we will both receive a £50 voucher for Ecotopia. So I can use it to buy my LED light bulbs once they get their new stock, and so can you! (or you can spend it on toilet paper and dishwasher tablets)

Until next time.

Carbon negative house. Someone’s beaten me to it!

So this weekend is Open House in London. It’s where places sign up to be open to the public and people can go and look around buildings for free.

The one that caught my eye is 3 Acorns which is a Victorian house owned by Donnachadh McCarthy, an eco-auditor (amongst other things). He converted his 1840’s Victorian terrace home into a retro-eco home, just like I want to do!

Unfortunately I am busy this weekend, so probably won’t be able to go visit (although I might try to regardless), but I have been reading his website with great interest.

The first thing that came to mind is I was dismayed that his wind turbine was not producing much electricity at all! I may need to rethink my ideas for a micro-turbine. However his one was installed in November 2005. I am hoping that in 2014 when I am ready to start thinking about turbines that Ecotricity’s Urbine is ready for market. My hope is that it will be more efficient (due to being vertical axis) to make it a viable option (although I guess depending on whether the area the house is situated gets enough wind is a bigger consideration). Also I don’t know what the garden situation would be like, but I’d prefer a free standing turbine as they are supposed to be more efficient (but more expensive). So that might eliminate the problem the 3 acorns house is experiencing with vibrations.

Then the second thought was, I don’t think that this is a good model for a sustainable house. Obviously Donnachadh knows what he is talking about and has created a house that has achieved exactly what I want to do, but… I don’t like the idea of a wood burner.

Yes you can argue that it’s carbon neutral as the carbon produced from burning the wood is offset by the carbon dioxide removed from the atmosphere as the tree grew. But this is not what I take issue with.

I want my house to be energy independent. His house used 48 wheelie bins of wood in a year. It is reliant on there being a supply of wood. Obviously this isn’t going to be a problem for one household, but if you were to scale this up and asking every house in the country to become carbon neutral, where would you get enough wood?

Also a common complaint of non-environmentalists is that we all want society to regress so we’re all back living in caves. These people are of course idiots, but I do think that we have the technological advancements that allow us to have a zero carbon house without having to resort to huddling round a wood fire to keep warm. I think people are more willing to make a switch to renewables / low carbon solutions if they are easy and familiar and seem like an 'upgrade'.

If you are producing enough electricity to feed back in to the grid, why not use that electricity to heat the house? Of course it might not be viable, or it may be more efficient to do things this way. I guess the only way to find out would be to visit the house on Open House weekend!

Regardless, it's provided me with a lot of inspiration, hopefully I'll be able to surpass 3 Acorns.

EPCs and a (theoretical) plan of action

So I’ve been doing research in to the best way to start retrofitting once we finally have our property. And it seems the best place to start is with the EPC. An EPC is an Energy Performance Certificate. The person selling a house needs to obtain them before they can sell. So when moving in to a new property you will receive a copy (a lot of property sites include them among the photos of the property).

They contain the building’s current Energy Efficiency Rating and Environmental Impact Rating. The first is your houses energy efficiency, the second is your houses impact in terms of CO2 emissions. It also includes ways that you can improve the ratings. Examples would be things like:

Cavity Wall Insulation

Draught Proofing

Condensing Boiler

I think starting with the list of suggestions on the EPC of the house will be the best place to start as it gives a good breakdown of costs of each solution and the benefits gained (in terms of money saved).

But in addition to making my new home energy efficient, I also want to make it zero carbon (or as close as possible). I have thought about this a lot and I think the only viable solution is to remove gas and have a completely electric household.

Green gas does exist. I currently buy my gas from Ecotricity (love them, more on them later) using their green gas tariff. But although they currently source their green gas from the Netherlands, I don’t believe they are supplying 100% green gas to their customers. And Ecotricity is working on establishing green gasmills in the UK but even then I imagine it would take years for supply to meet demand, and in the meantime continuing to contribute to the demand for gas encourages exploration of controversial techniques like fracking.

Plus, although I could just switch everything over to electric and buy my green electricity through Ecotricity the bills would be huge (hopefully less once I completed all the energy efficient solutions). I think the price of gas is going to increase in the coming years in a way that electricity isn’t.

For me the ideal solution is to generate my own renewable energy for the house, making it completely energy independent (or as much as possible). I have a passion for renewable energy, so having solar panels or a micro turbine was always my plan, but even if that were not the case I think my plans for energy efficiency would lead me down this path.

So having considered all this, the list of retrofitting improvements I’m planning to consider for my futurefitted house is:

Solar panels

Wind turbine

Ground source heat pump

Electric oven (with induction hobs)

Low-e double glazing

Loft insulation

Cavity wall insulation

Draught proofing

LED lighting

Note: I'll justify the solutions I've picked and the choice for them over other possible solutions in further blog posts.

For now this seems like a fairly complete list, but it is only once we manage to buy a place and get the EPC that any firm plans can be made. It will be interesting to see how the reality differs from today’s plan.

A welcome

Ok, so the idea behind this blog is to document my attempts to achieve my goal of making my house zero carbon and as energy efficient as possible. To create a sustainable house.

Before I can get started there's one small issue to address. I don't actually own a house... My tenancy is up in February 2014, and then my girlfriend and I will be buying a place. But I've been researching in advance and am just too enthusiastic about getting started to wait until then. So I thought I'd start now and it can also document any planning I do (and how this eventually differs from what becomes a reality when put in to practice).

Finally to explain the name of the blog. I'm fully expecting to have to retrofit an existing house as it's unlikely we'll find (be able to afford) a super environmental, efficient new build. But as I don't actually have a house yet, I'm not retrofitting anything yet, I'm making retrofitting plans for the future. Futurefitting.