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Housing - Renovation: Assessing heating needs

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  1.  
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      CommentAuthorMichael1
    • CommentTimeJan 17th 2009
     
    Hi all,
    Is there a formula for working out how much heat I need to put in to my renovation project, keep it simple now as Einstein i aint.To elaborate a little I am willing to put as much insulation as possible into it and am going to triple glaze and make it as airtight as I can,I would like a woodburner to help heat the water and to look nice but would like to get away from elaborate heating systems.
    Thanks
    • CommentAuthortony
    • CommentTimeJan 17th 2009
     
    You wont need any heating in it -- how big is it? what do you mean by as much insulation as possible?
    • CommentAuthorGotanewlife
    • CommentTimeJan 17th 2009 edited
     
    Michael,

    Your average Joe would build an extremely insulated and air tight house (in their view) and need some heat, but your average Joe isn't on this site - where, done properly, (that's PROPERLY) a new house doesn't need extra heat.

    Now to answer your question - for an average Joe non-Einstein assessment of how much heat your house needs, try this worksheet. I also found on one of the radiant skirting board heating sites a more complex and detailed worksheet (if you can't find it and want it, ask me) - and they both gave me the same answer for my house - and that was enough for me....being an average Joe myself with no way to insulate my solid, thick stone walls.
    http://www.energysavingtrust.org.uk/uploads/documents/housingbuildings/ce54.pdf

    So you must now decide whether you are an average Joe or whether you need to understand what you mean by "as much insulation as possible"! PS - Have you heard of Passivhus (or however you spell it) - me neither, but it crops up one hell of a lot on this site....might be worth you understanding the concept.
    • CommentAuthorJackyR
    • CommentTimeJan 17th 2009
     
    "Passivhaus", for search purposes.
    • CommentAuthorMarkK
    • CommentTimeJan 18th 2009
     
    spend £250 on a SAP calculation.
    Your architect will be able to help, or if you don't have one, search for sap assessor. You'll need accurate plans and construction details.
    •  
      CommentAuthorMichael1
    • CommentTimeJan 18th 2009
     
    Hi all,
    "as much insulation as poss" . It is a Stone Barn in Normandy and the wall are 500mm thick and to these I am going to add 500mm of Hemcrete bringing it around the window reveal 100mm,Limecrete floor 150mm, I am going to take off the existing roof and replace with roof panels that are pre insulated (can't remember the name).As I mentioned before I am going to install triple glazed windows and doors and get as best an airtight house as I can. Any ideas or improvements you can add to this are welcome.
    Thanks Gotanewlife for the link and all comments.
    Michael
    •  
      CommentAuthorMichael1
    • CommentTimeJan 18th 2009
     
    Forgot to add the size inside wall to wall is (including insulation) 10 metres by 6 metres and floor to eaves is 10 metres with an extention the same size with an Oak frame and Hemcrete and Limecrete as before, only 2 stories with open space to the ridge in both parts, bedrooms and bathrooms downstairs, cooking and living upstairs, the long dimensions are East/West so no windows facing North and large facing south.
    Thanks,
    Michael
  8.  
    http://www.plumbingpages.com/featurepages/Heatloss.cfm

    here is the basic formula for calculating heatloss, not to complicated I hope , you just need to get your U values for each element
    link below for a basic U calculator, doesn't have hemcrete I afraid
    http://enmanregister.com/tutorial/uvalue01/uvalue01.htm

    cheers Jim
    • CommentAuthorCWatters
    • CommentTimeJan 18th 2009
     
    This article is worth a read if interested in the thermal properties.

    http://www.limetechnology.co.uk/upload/documents/1201787723_the_thermal_performance_of_tradical_hemcrete.pdf

    It discusses the dynamic performance of hempcrete and claims this reduces the effective U-Value of hempcrete from 0.29 to 0.11. (See text below Fig 4). Some some care is needed interpreting this... It appears to apply during the first 24 hours of a cold snap where temperatures plunge 20C - it relies on the hempcrete acting as a thermal store. Presumable after after say 72 hours of cold weather a new steady state is reached and the U-Value is back to 0.29.

    Even if perfectly insulated and "air tight" you still have losses due to ventilation unless you install heat recovery.
    •  
      CommentAuthorMichael1
    • CommentTimeJan 18th 2009
     
    Hi CWatters,
    What type of heat recovery? Bathrooms and kitchen or whole house? also how do I determine what sort/type I need.
    Thanks
    Michael
    • CommentAuthorGotanewlife
    • CommentTimeJan 18th 2009 edited
     
    <blockquote><cite>Posted By: Michael1</cite>Hi CWatters,
    What type of heat recovery? Bathrooms and kitchen or whole house? also how do I determine what sort/type I need.</blockquote>
    Well that's easy! - just spend 500GBP on a air tightness survey after you have finished the house - what? You need to decide on your ventilation before you finish the house - ohh.....and you live in rual France which I bet is like Italy and airtightness is a BAD thing best avioded in fact......generalising what I have learnt from the Forum, bottom line is that whole house (heat recovery preferably) ventilation is absolutely essential (health and humidity reasons) if your house is above a certain level of airtighness, but a waste of money if it is below another level. In case you hadn't twigged I know little about this other than i can't see how i can decide (living it Italy) and I have plumped for the since it is difficult to get good good airtightness, and I have a very limited budget I'll do nothing head in the sand approach.....for now at least. Plenty on this subject on this Forum - let your fingers do the searching...
    • CommentAuthorCWatters
    • CommentTimeJan 19th 2009
     
    Posted By: Michael1Hi CWatters,
    What type of heat recovery? Bathrooms and kitchen or whole house? also how do I determine what sort/type I need.
    Thanks
    Michael


    From the very little I've read "single room" heat recovery units aren't very effective but I might have that wrong.

    We installed a whole house vent system in our self build and it seems to work well as a ventilation system. I'm not sure how to assess the performance of the heat recovery part. Certainly the air feels a lot fresher in the house than in any previous house we've lived in and there is not a hint of condensation anywhere. I liken it to living in a caravan or tent if you've ever done that you'll know what I mean. I would certainly install one again if I built another house.
    •  
      CommentAuthorMichael1
    • CommentTimeJan 19th 2009
     
    Hi Cwatters,
    Did you install this yourself and how did you come to find the one you needed. Is it against the rules to say who made your system?
    Regards
    Michael
    • CommentAuthorCWatters
    • CommentTimeJan 19th 2009
     
    We sent plans for the house (with the purpose of each room marked eg "Kitchen") off to several companies and asked for quotes. I won't recommend the company we used as their installers were rather poor. We choose them on the basis of price mainly. Perhaps a mistake. Take a look at:

    Regavent
    Villavent
    Vent Axia
    Kair/Kiltox
    Starkey Systems
    Viessmann
    Hampton?
    Rayotec

    There are probably a dozen others I've missed.

    The important thing is to choose the best place for the fan unit/heat exchanger. Ideally you want to avoid putting this right over your bed. While they are reasonably quiet they do make some noise. On our system the extract vents are audable but the entry vents are virtually silent and can't be heard when lying in bed unless the system is turned up to maximium. We operate ours on the minimium speed setting except when really hot in the summer. On this setting the flow of air is really quite modest. Only detectable if you put you hands near the vents - certainly they don't create draughts. This seems to be enough though.

    Some makes also offer "comfort cooling" and full air conditioning options - but they are far from green and aren't really necessary in the UK.
    •  
      CommentAuthorMichael1
    • CommentTimeJan 19th 2009
     
    Hi CWatters,
    Thank you for the info, I shall chase some of them up, we are going to be in Normandy so the cooling bit might be handy if its not to expensive, is DIY a possibility?
    Regards
    Michael

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