RefurbN16

Author: Jamie

  • TTSN 1st Birthday – Auction of Promises

    It’s Transition Town Stoke Newington’s first birthday celebrations on Thursday 21st. Come down to Pangea Project and join the party with all the other TTSNers.

    There will also be an auction of promises to raise funds for TTSN, with a very wide range of fantastic things up for grabs including singing lessons, french lessons, a rap workshop, GIMP lessons (something that I’m after and no it’s not what you’re thinking), a week of packed lunches,  tickets to London zoo, a music video shoot an osteopathy session…

    Check out the full catalogue.

    Bidding starts online and will finish at Pangea Project on the 21st. Hope to see you there.

  • LSE Sustainability in Practice Lectures

    The London School of Economics has pulled out all the stops and assembled a distinctly heavyweight array of sustainability thinkers who will be delivering lectures over the next couple of months:

    14 January: ‘Positive Deviance: the only strategy left for sustainability leadership’ by Sara Parkin at Hong Kong Theatre, Clement House.
    21 January: ‘Time for a New Policy Paradigm: resources, technology and human well-being’ by Professor Sir David King at Sheik Zayed Theatre, New Academic Building.
    28 January: ‘New Economics’ by Andrew Simms at Hong Kong Theatre, Clement House.
    2 February: ‘Delivering a Low Carbon London’ by Isabel Dedring at Hong Kong Theatre, Clement House.
    4 February: ‘Climate Crunch: making the economics fit the science’ by Jonathon Porritt at Hong Kong Theatre, Clement House.
    9 February: ‘Sustainable Housing: how can we save 80 percent of our energy use in existing homes?’ by Professor Anne Power at New Theatre, East Building.
    18 February: ‘The Radical Industrialist’ by Ray Anderson at New Theatre, East Building.
    25 February: ‘Prosperity without Growth’ by Professor Tim Jackson at Sheik Zayed Theatre, New Academic Building.
    4 March: ‘Education for Sustainable Development’ by Tony Juniper at New Theatre, East Building.
    11 March: ‘Sustainable Business Innovation’ by John Elkington at Hong Kong Theatre, Clement House.

    All lectures are free and open to all.

    Full programme here.

  • Queen Elizabeth’s Walk Pt 1

    One of the Building Group members, Yvonne, kindly hosted a well attended Buildings Group meeting last night, which included a couple of new faces.

    Her home is a south facing Victorian mid terrace with suspended timber floors and rooms up in the loft. It’s located on Queen Elizabeth’s Walk up near the reservoirs north of Lordship Park.

    Yvonne and her partner will be building a wider extension, amongst other work, and recognised that this would be the perfect opportunity to overhaul the rest of the home’s energy efficiency. They took a trip to the Centre for Alternative Technology in Wales where they received some excellent advice and had the opportunity to get up close and personal with a wide range of high performance building materials and technologies.

    The main energy efficiency work which they will be undertaking is challenging.

    The dormer roof has all sorts of angles and slopes which make insulating difficult. Multiple materials of varying thicknesses will be needed, but the important thing is to ensure that there is a continuous “tea cosy” (as Fran puts it) of insulation on all surfaces, even if it’s just a modest amount on some surfaces and more on others.

    The suspended timber floor needs insulation but has Parquet over the top which means that taking up the floorboards is not possible. Access to the space underneath the floor is very tight across much of the floor area so this could prove a bit of a headache, but there are options which we will cover.

    Yvonne is also looking at fitting microgeneration technologies. With the south facing roof, solar hot water and photovoltaics are clearly strong contenders. The feed in tariff is being introduced in April, which makes this a good time to be considering electricity generating technologies, but as always with microgeneration, you need to ensure that your energy consumption has been reduced as far as practicable before investing, which is exactly what Yvonne is doing.

    Update: Yvonne has started a blog charting her progress.

  • Boilers Pt 2 – Condensing Boilers

    In Boilers Pt 1 – Regular Vs Combi, we looked at the two main types of boiler which you find in the home. This post takes a look at replacement boilers, in particular condensing boilers.

    Since 2005, the Building Regulations have required that if you replace your boiler, you have to replace it with a condensing boiler. There are a few exceptions to this (see Appendix A here), but essentially all new boilers condense. But what does this mean?

    A condensing boiler is not all that different to your old boiler, but it is more efficient. To achieve this, condensing boilers are fitted with an extra heat exchanger. The heat exchanger transfers heat from the burning gas in your boiler to the water in your heating or hot water system.

    A heat exchanger is a very simple metal component through which water is passed. It has a large surface area which makes it easier for the heat to pass from the hot burning gases to the cooler water in the heating or hot water system. A radiator is an example of a heat exchanger, passing heat from the hot water to the air in your home.

    By adding an extra heat exchanger to the boiler, more heat can be extracted from the hot gases that would otherwise escape up the flue and into the atmosphere. This energy goes into preheating the water returning from the heating or hot water system, before it passes to the main heat exchanger to be heated up the rest of the way.

    The “condensing” part refers to the moisture (or “condensate”) which condenses out of the gases and is flushed down the drain. The action of condensation transfers additional heat to the heat exchanger (see here for the Wikipedia explanation).

    Condensing boilers reduce the temperature of the flue gases from about 150°C to about 55°C so there is a substantial amount of heat there to be recovered but they won’t always be in condensing mode. In order for this to happen, the temperature of the return pipework (which carries the water back to the boiler after passing through the radiators) has to be below 55 degrees.

    For this reason you need to make sure that a regular boiler is correctly sized for your home. This is one of the reasons why you should reduce the heat demand of your home as much as possible through insulation and draught proofing before replacing your boiler. If you do it the other way round, your boiler is likely to be too big and it won’t work as efficiently.

    Your boiler thermostat also needs to be adjusted so that the flow temperature (the temperature of the water leaving the boiler) isn’t so high that the return temperature is too high for the boiler to enter condensing mode. I’ll cover this in more detail soon.

  • Boilers Pt 1 – Regular Vs Combi

    Existing boilers in UK homes fall into two main types – regular boilers (which might also be called “heat only” or in some cases “system” boilers) and combination or “combi” boilers.

    A regular boiler delivers heat to both the heating system (usually radiators) and a separate hot water system which takes heat to the hot water cylinder. A hot water cylinder consists of a metal tank, hopefully well insulated, inside of which is a coil of tubing. The boiler passes hot water through this tube and this indirectly heats the water in the cylinder.

    So instead of taking the water to the boiler you take the heat to the cylinder. When you turn on the hot tap, hot water is taken from the top of the tank and replaced with cold water at the bottom.

    A combi boiler on the other hand, supplies heat directly to both the radiators and to the cold mains water so it directly heats the water itself and delivers it on demand to the hot taps. Combi boilers store no water and so they avoid the problem of sometimes heating up water that  just sits there cooling down (known as standing losses).

    Now you may be thinking “why bother with a regular boiler and hot water cylinder if you can avoid those losses?”, but there’s a catch with combis: they heat water less efficiently than regular boilers. So there’s a trade off between the benefit from avoiding standing losses and the penalty from reduced hot water efficiency.

    The upshot of all this is that a combi is most suitable for smaller homes with a low hot water demand while a regular boiler is most suitable for a home with high hot water demand. Combis are also more suitable in smaller homes because they don’t need the space for a cylinder.

    In my flat I unfortunately have a cylinder which means that I don’t use anywhere near the full amount of hot water. But it is very well insulated with factory fitted foam which means that I just have it come on once before I get up and there’ll still be hot, well warm, water when I get back in the evening.

    There is a trend at the moment towards the inappropriate replacement of regular boilers with combis but it should be resisted. If anything, removing the cylinder makes it that little bit harder and more expensive to install a solar hot water system, which needs as much storage capacity as possible, so if you’re considering going down this route you should try and keep hold of your cylinder.

    Next up we’ll cover high efficiency condensing boilers. If you want to read in more detail about gas heating systems then your best bet is to check out the Energy Saving Trust publication Domestic heating by gas: boiler systems (CE30)

  • Heating Controls Pt 1 – Introduction

    Given that it’s bloomin’ freezing outside, I thought I’d write the first post on setting your heating controls.  This post will be an overview to the whole set of controls and it’ll take a few more posts to cover the whole lot.  For many this is a confusing subject so hopefully this post will help shed some light on a difficult area.

    Ideally your heating system should have at least 3 basic controls: a boiler thermostat, a room thermostat and a programmer. We’ll deal with them in reverse order.

    The programmer has overall control over when the boiler is switched on and off. It doesn’t have any temperature setting, just time settings. They come in varying degrees of sophistication from the most basic (which I unfortunately have) which can’t control the hot water and heating independently, to all singing and dancing, fully programmable digital devices. If the programmer is set to on, it doesn’t mean the boiler will be chugging away all of the time – the boiler should kick in and out in order to maintain a comfortable room temperature.

    This overall house temperature is set by the room thermostat, which is usually found in the hallway or living room of a home. It senses the temperature of the room and tells the boiler to switch on if it is below the set temperature and switch off if it rises above it. As a result your room temperature will bobble up and down slightly above and below the set temperature. The room thermostat can’t override the programmer so it will only have an effect if the programmer is in its on phase.

    The boiler thermostat is mounted on the boiler and controls the temperature of the water flowing out of the boiler and into the pipework and radiators. It tells the boiler how long to burn for in order to raise the water to the set temperature.This control is frequently overlooked and is usually the least well understood thanks to generally poor design.

    In an ideal world, all of these three controls will work together in perfect harmony to maintain the temperature of your home. By setting them correctly you can achieve this with minimum energy consumption.

    Clear? As mud? Post a comment below if you want me to clarify anything. I’ll be going into more detail on this very soon.

  • Boiler Scrappage Scheme Launched Today

    The other big news today was the launch of the boiler scrappage scheme by the Department for Energy and Climate Change (DECC). The full details of the scheme can be found here, but here is the 30 second version…

    The scheme is offering 125,000 homes a £400 voucher on a first come, first served basis if they scrap their G rated boiler and replace it with an A rated condensing boiler. Condensing boilers are more efficient than conventional boilers because they extract additional heat out of the exhaust flue that would otherwise escape into the air.  They shouldn’t be confused with combination (combi) boilers which are boilers which don’t have a hot water tank, heating the water directly instead.

    The building regulations require (with a few exceptions) at least a B rated boiler to be fitted so this is pushing the bar a little higher, which is a good thing.

    The way it works is that once you’ve identified your G rated boiler and have received a quote that you’re happy with, you contact the Energy Saving Trust. From January 18th, cashback vouchers will be sent out and you should receive the voucher about 10 days after application. You then have 12 weeks to have the boiler installed and the voucher signed off by the plumber.

    A word of caution… You might well be quoted wildly different figures, some of them way too high (naming no names of course), so make sure you get a good selection of quotes. If you can find a good local plumber recommended by word of mouth, that might be the best way. Just be aware! There’s also a wide range of boilers. Some are cheap but poorly constructed and with expensive parts.

    You can find out if your boiler is G rated here. If you’re having difficulty, post a comment and I’ll see if I can find it (it’s not always completely obvious).

    Now while this is a good offer (it’s equivalent to a discount of about 15% to 25%), it’s really best to consider reducing your energy demand before you replace your heating system. This will mean that the boiler can be correctly sized to the heat demand of the home. Having said that, this is a one-off offer and is highly unlikely to be repeated.

  • Multi-Million Pound Insulation Scheme Begins In East London

    Sorry for the pause over Christmas and the New Year. I trust everyone had a nice and relaxing time…

    Some good news for Hackney to kick off the new decade:

    The importance of energy efficiency in buildings has been realised by Hackney Homes ahead of their £2.9 million programme of insulation work in east London.

    Having secured a grant from the Homes and Communities Agency, the organisation, which managed council properties in the London borough, has appointed Lovell to carry out the work on its range of flats.

    Cavity wall insulation will be installed on approximately 50 blocks of flats, with the work expected to have been completed in June.

    Hackney Homes’ director of property services Gary Penticost said he is “pleased” to be working alongside Lovell on what he called an “important programme”.

    “Improving insulation in our harder to treat cavity walls will give our tenants not only better insulated homes, but homes that are cheaper to heat,” he commented.

    London Energy Efficiency is also involved in the scheme, Lovell confirmed.

    Lovell is also involved in a major housing improvement scheme in Derbyshire, with a number of apprentices being given the opportunity to work on the scheme.

    Sign up to receive regular e-news for more information.

    I can’t find this news article online (it just dropped into my inbox) but I’m sure it’ll surface soon.

  • TTSN Social This Thursday – Food & Live Music

    Once again we have our regular monthly social, this time hosted by the Food Group. As ever, these socials are a great time for new members to come and find out what is going on, as well as being a lovely way for us all to keep in touch, and learn something new.

    The evening will start with a shared meal from about 7.30. This will be followed by a short presentation by the food group including a film or two about fishing. At ten, the Rocky Mountain Boys will have us toe tapping to Blue Grass. Come along!

    It’s on Thursday from 7pm to 11pm at Pangea Project. For more information please click here.

  • Draught Proofing Pt 1 – Ventilation Vs Draughts

    Air tightness is a very important part of an efficient, low carbon home. You can have the best insulation in the world, but if the warm air is blowing out through cracks and gaps in the fabric of the building, you’re not going to see those benefits.

    Equally, ventilation is a very important part of a fresh, comfortable home. Good ventilation allows stale air from in the home to be exchanged with fresh, clean air from the outside. It allows odours and gases such as carbon monoxide and volatile organic compounds to escape into the atmosphere and it removes moisture from the air. Moisture is created through normal household activities such as cooking, washing and drying and it is critical that it is removed from the home so as to avoid condensation and damp.

    The trick is to achieve the correct amount of controlled, desirable ventilation that allows the air in the home to be exchanged with fresh air from outside, while reducing the uncontrolled and undesirable draughts.

    You can measure the rate at which air leaks from a home by conducting an air permeability test. This involves blocking all of the vents up, closing windows and doors and generally sealing off all of the controlled ventilation routes. A screen fitted with a powerful fan is then placed over the door and the air pressure within the home is increased. By measuring how much power is required to maintain this pressure, you can calculate the air leakage rate.

    Knowing the rate at which the air escapes through gaps and cracks is all well and good, but really you want to know where it’s escaping so that you can do something about it. Often you can tell that there’s a draught in a room but it’s not possible to work out where. During the pressure test someone walks around the home with a smoke generator, checking likely areas to see if there is a draught – the smoke will follow the air through any crack and out of the home.

    Draughts can occur all over the home – gaps between suspended timber floorboards, around skirting boards and electrical fittings, at the join between walls and the join between floors and walls, around pipework penetrating the fabric, around loft hatches, up chimney, through letter boxes and keyholes and of course around doors and windows.

    The next post on draught proofing will cover the quick and easy measures you can take to start improving the air tightness of your home – it’s cheap, easy, DIY and well worth doing.