RefurbN16

Author: Jamie

  • Heating Controls Pt 2 – Programmer and Room Thermostat

    This one often causes vigorous disagreements, but I’m going to stick my oar in and describe how I think the programmer and room thermostat (see Pt 1 for a description of these controls) should be set in a home.

    The very quick version is:

    1) Work out what the minimum comfortable room thermostat setting for your home is and then

    2) Set the heating to come on for as little time as possible

    It sounds simple but there are some subtleties to it that I’ll discuss now. Unfortunately there isn’t a great deal of hard research to go on. This is my best guess and I’m happy to hear contrary views. If anyone can dig up proper research, I’d appreciate it.

    Now first up, there is some evidence to suggest that if the fabric of the house is cold then you need to heat the air to a higher temperature in order to feel warm. The thinking goes that the additional radiated heat from the walls makes a difference to comfort and as a result, if you let the walls warm up you can get away with a lower air temperature.

    This is borne out by plenty of anecdotal tales of people changing from bimodal heating (having it on twice a day) to continuous heating but setting the room thermostat to a lower temperature and reporting energy savings while still being comfortable.

    Unfortunately it’s very difficult to compare two different heating patterns because your home’s energy consumption is so dependent on the outside air temperature (it is possible though by taking regular meter readings and doing a degree day analysis, but that’s for another time).

    Turning your thermostat down does lead to substantial savings. Everything else being equal, heating consumption is cut by about 10% per degree you turn it down. But having your heating on all the time? I’m certain that’s not efficient because you’re heating the home when you’re fast asleep or out of the house and I’m sure you could at least shut it down for a few hours in the middle of the day or night.

    If your home is not very responsive (i.e. it takes a long time to heat up), which many solid wall homes are, it might take a long time to heat up the walls and so it might seem like you’re ignoring the second part of the above advice.  might mean that you need to have the heating on for quite a while in order to get the fabric of your home up to temperature.

    So here is my patent pending method for setting your heating programmer and room thermostat:

    A bit of experimentation is called for…

    Stick your heating on for a good length of time on a reasonably chilly day and let the fabric of your house completely warm up and stabilise at a higher than usual temperature. Then start lowering the room thermostat until you get to the lowest temperature at which you are still comfortable. Depending on your home it may take a little while to let the temperature adjust.

    Next turn your heating system off and note how long it takes to cool down enough so that you’re starting to feel a wee bit nippy. This is your home’s cooling down time, we’ll call it C. When your home’s cooled down completely, turn it back on and work out how long it takes to get back up to the comfortable temperature. This is the warming up time, W.

    You then want to set your heating so that it comes on W minutes before you wake up in the morning and switches off C minutes before you leave the house. Set it to do the same before you get home in the evening / go to bed.

    If you have it on any longer than this, you’re heating your home unnecessarily, but do bear in mind that it might take a while to get the fabric of the house up to the right temperature.

    Does that make sense? It’s not an exact science but this is the best I’ve been able to come up with. As I said, comments gratefully received!

  • New Transition Town Stoke Newington Website Launched

    After various problems with the ning site, we now have a shiny new website which is looking very good indeed:

    http://ttstokenewington.org.uk

    It’s got group pages so you can see the latest happenings in each of TTSN’s gropus, a forum for more live discussions about everything Transition, an events calendar, social networking tools, blogs, video and picture uploads. Basically it’s got it all and it looks lovely. Good work for setting this up Selim!

    Go and register, join the Buildings Group (and any others that are of interest) and start communicating! The ning site will slowly be phased out but will be open for a while as people move across.

  • Secondary Glazing Pt 1

    Many of the homes in Stoke Newington have single glazed sash windows. These leak heat very readily, both directly through the single pane of glass and through gaps around the frame.

    Double, or even triple glazing is the most effective solution to this problem. The multiple panes of glass are separated by a sealed gap filled with air or a dense gas such as argon. By completely sealing this gas you get very little movement and this reduces heat transfer.

    Air is a very good insulator, as long as it isn’t allowed to move too much, because it is a poor conductor of heat. If it moves, it will transfer heat across a gap through convection. This is exactly how a wooly jumper keeps you warm – the fibres keep pockets of air stationary, keeping the heat in. Argon works even better because it is denser than air and movement is further reduced.

    While multiple glazing is the most effective solution (and one we’ll go into in more detail), it’s also a pricey solution and if you live in a conservation area, it may not be an option open to you.

    A cheaper solution, and one that doesn’t change the outside of your home, is secondary glazing. This is not as effective as multiple glazing but it does make a substantial difference. By fitting an additional pane of glass or perspex on the inside of your window you save energy in two ways: you cut out the draughts coming in around the frame and the additional pane of glass traps a layer of air that acts as an insulator.

    Secondary glazing is often removable, so you can fit it during winter and remove it during the summer. Other types are fixed permanently, opening like the window they are covering.

    In part 2 we’ll take a more detailed look at different types of secondary glazing, but before I go, here’s something I haven’t seen before: DIY magnetic secondary glazing. You get a reel of steel tape and a reel of magnetic tape, each with adhesive on the back. You fix the steel tape to the window and the magnetic tape to some perspex.

    Does anyone have any experience of this? Seems like it might just work… Would the strips look odd? Maybe if they made the strips white they could merge quite nicely with your window frames.

  • Draught Proofing Pt 3 – Easy Draught Proofing

    In part 1 we looked at the difference between ventilation (which we need) and draughts (which we definitely don’t need). Then we looked at the ways air can leak out of your home.  Now we can start looking at doing something about it.

    There are some obvious gaps to block in most homes. The keyhole and letterbox are prime contenders for your first hit. It’s quick and easy and cheap.

    Unused (or rarely used) chimneys should also be blocked as they’re big holes in your home which let the air out easily. You can buy chimney balloons but they’re on the expensive side.  Improvise and let me know what works.

    If you live on the ground floor and you have suspended timber floors, it’s likely that you have cold air from the cellar coming up the cracks between floorboards and around the top and bottom of the skirting boards. These gaps can be blocked using a silicone sealant (mastic) which you can get in different colours. This isn’t a quick job but you can do a bit at a time as and when you have a moment.

    Lastly (for the moment), check out any pipework that passes from the warm interior to a cold space whether it’s outside or to the cellar or loft.

    Your home will have an array of pipes which provide the services that you need (gas pipes, waste water, boiler flues, electricity cabling etc) passing through the structure. These often have holes bigger than the pipes that pass through them and air will leak in and out as a result. You can use either silicone sealant or you can get pipe collars (grommits) that attach to the wall and fit snugly around the pipe. Airtight adhesive tapes might also prove useful.

    So there are some starting points. If you want to read more, check out the Energy Saving Trust’s Improving Air Tightness in Dwellings and the Scottish Ecological Design Association’s Design and Detailing for Airtightness.

    More to come!

    http://www.seda2.org/dfa/dfa.pdfD

  • Details of UK Feed In Tariff Announced

    The overdue announcement of the UK’s Feed in Tariff (FiT) is at last being made by Ed Miliband today, ending a period of uncertainty for the UK microgeneration industry. FiTs have, for the most part, been hugely successful in a wide range of countries around the world and their introduction to the UK is long overdue.

    The good news is that it’s looking better than expected; it’s certainly better than the rates proposed in the consultation.

    The key to the success of FiTs is that they offer security to people considering making the leap into the microgeneration world. The UK FiT will be have a lifetime of 20 years (25 years for solar photovoltaics) and should mean you can make a return of about 8% on the investment, considerably better than what any bank will offer!

    The UK FiT will pay a fixed incentive for every unit of renewable electricity generated by microgeneration systems, whether the electricity is used on site or exported to the grid. The rates paid (detailed here) will vary depending on the technology and the size of the system.

    For retrofit solar photovoltaic installations up to 4kW, the initial rate will be 41.3p/kWh (about 5p/kWh higher than the rate put out for consultation which is very good news). The average size of a residential PV installation is about 2kW to 2.5kW. Rates for larger PV installations are lower presumably because economies of scale will start to kick in you’ll get a lower installation cost per kW.

    Small wind turbines are also eligible but not recommended in urban locations, along with micro hydro (probably a bit tricky in N16) and anaerobic digestion (ditto).

    The announcement also includes details of the Renewable Heat Incentive (RHI) which is due to be introduced next year. My reading of the press release is that solar hot water will get 18p/kWh but that’s so high I can’t believe I’m reading the table right.

    The FiT rate that an individual receives will be constant over the FiT lifetime but for some technologies the rate will reduce for later entrants, so the later you get involved, the lower the FiT paid over the lifetime rate will be. To illustrate, if you buy a PV installation this year you will get 41.3p/kWh, if you buy it in the third year you will get 37.8p/kWh.

    On top of the FiT, any electricity you export to the grid also has value. The consultation was proposing to fix the export tariff rate but I can’t see any evidence of that in this press release, but you can search for the best export tariffs on the Energy Saving Trust’s website.

    More good news is that the FiT will apply to installations made after July 2008 rather than July 2009 as proposed in the consultation. This is good because it means that some of the early adopters won’t be penalised for being ahead of the curve, although many will. (see update below)

    Of course these things don’t come for free though and the cost of the FiT will be shared around all households, with the levy expected to be around £10 per year per household.

    This is a fantastic incentive which will give the UK microgeneration industry a much needed boost, however you should really have done everything you can to lower your energy demand before opting for microgeneration technologies. Look at your home’s electricity consumption, insulation, air tightness and boiler efficiency before looking at microgeneration.

    Updates:

    • It turns out that the DECC press release has a typo in it and installations made before 15th July 2009 will be ineligible for the FiT. Details can be found in point 179 of the Government’s Response to the FiTs Consultation.
    • The export tariff has been reduced from the proposed 5p/kWh to 3p/kWh
    • FiTs and export tariffs will be indexed to the Retail Price Index so they will rise with inflation.
    • FiT income from domestic installations will not be taxable for the purposes of income tax.
    http://www.decc.gov.uk/Media/viewfile.ashx?FilePath=Consultations\Renewable%20Electricity%20Financial%20Incentives\1_20100201131016_e_@@_GovernmentResponsetotheFITsConsultation.pdf&filetype=4

  • DIY Chimney Balloons?

    Do you have an open fireplace in your home? Go over to it and see if you can feel a draught going up the chimney.

    If the fire is not in use then a really smart move is to block up the flue. If your fire is in occasional use then please, please, please be careful if you do stick something up there – some sort of reminder in eyeshot might be a good idea.

    During the summer months, make sure you remove the obstruction to let any moisture that might have built up clear away.

    I’ve been investigating chimney balloons but all I can find are ones priced somewhere north of £15 which to my mind is just a tad expensive. So I’m opening it up to see who can come up with the best,  cheapest, most sustainable DIY solution.

    Someone suggested using the foil balloon in a box of wine. Would that work? I think it might on narrower chimneys. Thoughts?

  • Draught Proofing Pt 2 – Air Leakage Routes

    In Part 1, we looked at the difference between desirable ventilation versus undesirable draughts. In this post we will look at the pathways through which warm air can leak out of your home. For every bit of cold air that blows into your home, an equal amount of warm air is escaping so by tackling these weak points, you can cut heat loss from your home substantially.

    The best way to identify where the gaps are is by having a pressure test. We will be looking into the possibility of having some tests done on homes in Stoke Newington and will record exactly what happens so that you can get a  good idea of the process. Even without a pressure test, you can frequently identify sources of draughts simply by feeling for them on a windy day.

    Greenspec, a useful site with all sorts of interesting information on it, has a good diagram and list of the range of pathways by which air can leak out of your home. Fixing many of these routes is a DIY job, in particular draughts found around window and door frames, skirting boards, letter boxes, key holes, pipework and loft hatches.

    Have a look at these parts of your home next time it’s a bit windy to see if there’s a gale blowing through them. You can also see if there is warm air being blown out by getting a joss stick and passing the smoke trail around these points.

    Another useful publication is the Energy Saving Trust’s Improving Air Tightness in Dwellings which has lots of good information on how to reduce unwanted draughts.

  • Improving Traditional Windows

    English Heritage has published some interesting research looking at improving the energy performance of existing, traditional windows as an alternative to replacement.

    Unless you live in a conservation area or live in a listed building, under the Building Regulations replacement windows have to be double or triple glazed. The look of modern windows is, for the most part, very different to old windows and many consider them to adversely affect the aesthetics of older homes. For many people the cost of replacement windows is also prohibitively high so this research is also useful for them.

    Timber frame sash windows with double or triple glazing are available and there are designs which get pretty close to the sorts of windows you see around Stoke Newington.

    Luckily there’s a lot you can do to improve your existing windows and reduce heat loss. It won’t save as much as installing proper high performance multiple glazed windows, but through a combination of simple measures such as thermally lined curtains, improved draught proofing and secondary glazing, you can make substantial savings without spending lots of money.

    You can read the full report here or there is an executive summary here.

  • Carbon Conversations

    Here’s an interesting project I’m helping out with. Carbon Conversations is a series of  workshops which will help you reduce your impact on the environment.

    This lovely course was developed by Cambridge Carbon Footprint and covers five areas: climate change and living in a low carbon future, energy in the home, transport, food and consumption and waste.

    If you’re looking to lower your carbon footprint but you’re not sure where to start, then this course is ideal. Please email me if you want to find out more and forward this to any friends who might be interested.

    The first round of Carbon Conversations has started but there will be another coming up after Easter.

    Check out the Carbon Conversations video and below for further information…

    Carbon Conversations

    Carbon Conversations is a free 6-session course that will help you plan to halve your personal carbon footprint and save money on your energy bills. You will join a group of 8-10 adults who will meet fortnightly for six sociable evening meetings covering home energy, travel and transport, food and water, other consumption and waste.

    The meetings are hosted by friendy facilitators and use a fun mixture of games, discussions and role play which put you in charge of choosing how to reduce your footprint. We’ll help you understand the issues around climate change and learn practical ways to reduce carbon, save energy and money.

    By the end of the course, you will have created your own plan for reducing your carbon footprint, suited to your home and lifestyle.

    London Carbon Conversations will support your efforts in carbon reduction

    We’ll give you information about local grants and offers, signpost you to local groups and initiatives. We’ll also provide you with  book and DVD libraries, loan of energy monitors and a web-forum where you can contact other London Carbon Conversations members and ask experts for advice.

    How much does it cost?

    The course is free to participants, but we do invite you to purchase the course handbook (£15) and share venue costs where applicable (usually total around £5 for the course).

    Where are courses being run?

    Starting shortly there are four courses in Islington, two in Hackney, and one each in Lambeth, Westminster and Waltham Forest. Please see the detailed list of venues at the bottom of this email.

    Who else is using the Carbon Conversations method?

    The Carbon Conversations method is being used in various contexts; residents groups, green champions networks, schools, workplaces and faith groups. It is also being used in other community groups like Transition Initiatives and Climate Action Networks to help increase carbon knowledge and build community.

    Are you Running a 10:10 or community initiative?

    When you have completed a London Carbon Conversations course, you can partner up with another co-facilitator, complete a funded half day’s facilitation course and then start to run your own groups in your community. Please see the signature at the bottom.

    Start dates and venues

    Islington (N1 and N5)

    • Wednesdays 7:15 – 9:30 from 27th January Angel N1
    • Tuesdays 7-9pm from 2nd February – Highbury N5
    • Thursdays 7-9pm from 28th January – Highbury N5
    • Day TBD Highbury N5

    Hackney (N16 and E8)

    • Mondays 7:30-9:30pm from 1st February – Transition Town Stoke Newington – Pangea Project
    • Mondays 7:00-9:00pm from 25th January – London Fields E8

    Lambeth

    • Thursdays 7:30-9:30pm from 28th January – Vauxhall

    Westminster

    • Wednesdays 6:00-8:00pm from 27th January – Victoria Street/ St James Park SW1

    Carbon Conversations were created, tried and tested by Cambridge Carbon Footprint. London Carbon Conversations are run by the Carbon Literacy Forum, a non-profit community group based in North London.

    Carbon Literacy Forum

    Bridging the gap between awareness and action on climate change
    Empowering you to reduce your carbon footprint

  • January Open Thread

    This thread is the first of a series of monthly open threads. If anyone wants to pose a question about household energy efficiency in the comments below then please feel free.