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    •  
      CommentAuthordjh
    • CommentTimeDec 9th 2017
     
    A lot depends on how many cloudy days versus sunny days we get. A well-insulated house will still cool down a bit on cloudy days but will tend to make up losses on sunny days, even if it is colder outside. Normal houses tend to perform more depending on the external temperature rather than the quantity of sun.

    Posted By: Simon StillWe're not putting much heat into those rooms at all but I'm glad we are able to.

    Exactly. It's way better to have some heating that you only use a bit than not to have planned it and then try to keep comfortable.
    • CommentAuthordelprado
    • CommentTimeDec 10th 2017
     
    I wonder whether my solution is electric underfloor upstairs given my hated for radiators? Yes it’s wxpensive to run but hopefully I shouldn’t be using it much much?
  1.  
    Electric ufh is great in our downstairs bathrooms, has separate timers to come on at shower times, warm on bare feet, dries drips off.

    But needs lots of insulation underneath it, and I don't know if it works well with carpet, so haven't tried it upstairs. They do require some faff to lay, screeds and the like.

    For low cost 'insurance' heating, I'm going with electric wall panel heaters. These arrived this week, look great but not tried yet: https://www.amazon.co.uk/ADAX-NEO-Electric-Panel-Heater/dp/B008Y02ISK
    • CommentAuthorRex
    • CommentTimeDec 11th 2017
     
    We were advised that with the high insulation specs, that perhaps we did not need heating on the f/f. Glad I ignored that advice.

    But on a slightly different topic, would you buy a house that did not have f/f heating when the seller tells you, it is not necessary? i would not!
    • CommentAuthorSimon Still
    • CommentTimeDec 12th 2017 edited
     
    Probably worth putting some £ figures against this. I worked out our annual heat load by looking at the 12 month gas use and then subtracting what we used to heat water in summer months carried through the year.

    Our heat load is about 5000kWh.
    On gas at 4.2p a unit that's only £210 p.a.
    Electricity we're paying 16.75p now so electrical heating would cost us £837p.a.

    If half the heating was coming from electric then the incremental cost is c£300 a year. We self installed UFH from Wundafloor - cost of parts for an acoustic panel overlay system for the upper floors ended up being a bit under £3k.

    I'd say it looks as if it's worth putting in wet ufh (if you don't charge for your own time)
  2.  
    Our experience is that MVHR doesn't equalise temperatures very much at all, and that heat from UFH downstairs doesn't rise enough to compensate for the greater heat loss upstairs. It also seems to have been unwise to put the main thermostat in the downstairs living area which gets beautifully warm and switches off the boiler while the upstairs rooms and lower ground floor entrance hall are still a bit chilly.
    •  
      CommentAuthordjh
    • CommentTimeDec 19th 2017 edited
     
    Posted By: yclairejenkinsIt also seems to have been unwise to put the main thermostat in the downstairs living area which gets beautifully warm and switches off the boiler while the upstairs rooms and lower ground floor entrance hall are still a bit chilly.

    That should be fairly easy to fix. Wireless thermostats are widely available and simple to fit. I don't mean these new-fangled 'smart' things, just traditional thermostats from Honeywell/Danfoss/etc that are portable and connect to a receiver at the boiler by wireless. We had one that worked very well.

    edit: or just turn up the thermostat in the living area :)
    • CommentAuthorCerisy
    • CommentTimeDec 19th 2017
     
    While we hoped that the MVHR would transfer the heat around the house more effectively, we have an open plan main living area that includes the staircase. When we light the wood burning stove (our only heating, apart from the underfloor in the small en-suite) the heat naturally warms the upstairs - we keep the bedroom doors closed so they don't get too warm! Last night our bedroom was 18 degrees when we went to bed and stayed at that temp right through the night, despite the external temp dropping well below freezing.

    The PassivHaus level of insulation is the key of course, but overnight the MVHR clearly helps! We have only used a summer duvet in the two years since we finished the build!
  3.  
    Posted By: yclairejenkinsOur experience is that MVHR doesn't equalise temperatures very much at all, and that heat from UFH downstairs doesn't rise enough to compensate for the greater heat loss upstairs. It also seems to have been unwise to put the main thermostat in the downstairs living area which gets beautifully warm and switches off the boiler while the upstairs rooms and lower ground floor entrance hall are still a bit chilly.

    I think that why zoned heating was invented (with separate thermostats)
  4.  
    It is zoned, but the way it's installed, the main thermostat has to be calling for the boiler to come on, so the other zone thermostats have no effect unless the living room is below its set temperature. I don't know if there is an alternative way it could have been done, but this is how we were told it had to be.
    In fact we had the plumber back recently and he put on the 'weather compensation' which I had thought we wouldn't need if we were keeping very stable temperatures in a PH; it seems to be keeping the boiler running most of the time, but at a very low rate, which is good for giving the whole house a chance to reach its set temperatures.
    However it's now reading well over the set temperature (eg 23.2 when set to 20 atm) which is hotter than we really want it.
    It's our first winter, and I guess it takes a while to get familiar with the quirks of the tech and fine tune it.
  5.  
    Posted By: yclairejenkinsIt is zoned, but the way it's installed, the main thermostat has to be calling for the boiler to come on, so the other zone thermostats have no effect unless the living room is below its set temperature. I don't know if there is an alternative way it could have been done, but this is how we were told it had to be.

    I would have thought it should be possible to wire it so that any thermostat would turn on the boiler. But then the same thermostat will need to turn on the pump and the control valve for the zone - and then some circuitry to stop back circuits, nothing that could not be done with a circuit board and a few relays.
    • CommentAuthorcjard
    • CommentTimeDec 19th 2017
     
    Clearly your plumber had never heard of a wiring centre..
    • CommentAuthorcjard
    • CommentTimeDec 19th 2017
     
    Not that he should be doing wiring of course,p; that's your part P certified sparky's job
  6.  
    <blockquote><cite>Posted By: yclairejenkins</cite>I don't know if there is an alternative way it could have been done, but this is how we were told it had to be.
    </blockquote>

    What form of heat emitters do you have - radiators, underfloor or something else?

    It sounds as if someone has made a pigs ear of your install. You might want to think about getting someone else in to look at it. My experience is that most heating engineers/plumbers/electricians in the UK are very stuck in their ways and just do what they know. A very low energy house benefits from a different approach.

    It's a little worrying if the zoning is properly independent.

    <blockquote><cite>Posted By: yclairejenkins</cite>
    In fact we had the plumber back recently and he put on the 'weather compensation' which I had thought we wouldn't need if we were keeping very stable temperatures in a PH; it seems to be keeping the boiler running most of the time, but at a very low rate, w</blockquote>


    My heating runs solely off the weather compensation controller with no internal thermostats. Heating runs constantly (off for 5 hours overnight) at a low but variable temperature. The weather compensation increases the flow temperature as it gets colder outside. There was a few months of minor tuning to get it right in the first winter but now it just does it's stuff and temp doesn't really stray beyond 1C either side of 20C.

    I wonder if he's done some reading and switched from using the thermostats to the weather compensation?
  7.  
    This has spurred me into looking for info on how the weather compensation actually works - as far as I can find out, it's all on the flow and return temperatures and heat curve parameter settings and possibly not related to the thermostats at all? Though it seems odd that you'd be giving up that bit of user control completely.
    Our is a Worcester-Bosch boiler with Wave controller and underfloor heating. It's the Wave which only will only control a single zone; the subsidiary thermostats can only turn individual loops of the UFH on and off at the manifolds.
    As it has been for the last few days, the balance of temperature around the house is fine; it's just that the overall temperature gets a bit above optimal.The guy said something about the system learning, so it may settle down, or I may need to play with the parameters.
  8.  
    Posted By: yclairejenkinsIt's the Wave which only will only control a single zone; the subsidiary thermostats can only turn individual loops of the UFH on and off at the manifolds.

    It is the signal that the subsidiary thermostats use to turn on the individual loops that is used to switch the boiler on and off so the wave would only control the living room loop.

    If it is the wave controller that I saw on google - do you really need the ability to control your heating from anywhere in the world?

    Posted By: yclairejenkinsAs it has been for the last few days, the balance of temperature around the house is fine; it's just that the overall temperature gets a bit above optimal.The guy said something about the system learning, so it may settle down, or I may need to play with the parameters.

    If it continues running the heating in an acceptable fashion then maybe nothing extra needs doing - if not then consider getting the loops individually controlled.
  9.  
    Peter - Controlling the heating from abroad was definitely not the priority! Though it is quite interesting to see the temperature in the house while we're away, especially when our daughters have borrowed the house. But it was apparently no more expensive and saved a penetration and fixings for an outside sensor as it goes on the Met Office instead.
  10.  
    Posted By: yclairejenkinsThis has spurred me into looking for info on how the weather compensation actually works - as far as I can find out, it's all on the flow and return temperatures and heat curve parameter settings and possibly not related to the thermostats at all? Though it seems odd that you'd be giving up that bit of user control completely


    It did occur to me that if you had room stats it would be possible for the system to self-set up (ie alter the heat curve) over time. without them I just used some min max thermometers over the first winter and did the tweaking of the heat curve myself. I did need to alter both the level and the slope of the curve so you need a good range of outside temperatures to tune it.

    We have ours set up just as two zones - one under concrete, one under wood. No need to control individual loops.
    • CommentAuthordelprado
    • CommentTimeDec 28th 2017
     
    Hi all after further thoughts on this, does anyone have a view on warm air heating? Looks like it might be a nice solution for upstairs in a house?
    • CommentAuthortony
    • CommentTimeDec 28th 2017
     
    Best to design with no need for heating, if you go that route beware of noise from grilles.
    •  
      CommentAuthorSteamyTea
    • CommentTimeDec 29th 2017 edited
     
    Posted By: delpradoanyone have a view on warm air heating?
    It can be noisy, and sounds from one area to another can be transmitted.

    I had forced air heating when I was in the US (Pennsylvania, so cold, hot, humid and dry, all in a year) and it worked well. Heated the place up fast, was stable and allowed controlled fresh air in as well.

    It does seem strange to me that we put in separate heating and MVHR systems in, why not combine the two. It does mean that you need room for larger pipework, but if you design that in from the start it should not be a problem.
  11.  
    Posted By: delpradodoes anyone have a view on warm air heating?

    We have a Genvex Combi 185 that provides warm air heating as one of it's functions. The warm air temperature is between 40C and 45C. It is provided, when required, through the ventilation ducting so only a small amount of warm air is produced. This is fine in a PH but would be useless as a way of keeping a building regs. house warm.
    • CommentAuthorMike1
    • CommentTimeDec 29th 2017 edited
     
    Posted By: delpradoHi all after further thoughts on this, does anyone have a view on warm air heating? Looks like it might be a nice solution for upstairs in a house?

    I spent several years living in a house with warm air heating. Thermally it worked very well, but due to the volume of air being blown around it had return air grills above all the doors - essentially a cosmetically concealed hole with no noise suppression, so it was somewhat noisy (though I've also lived in houses with thin stud walls that were just as bad). That could have been avoided by building in return ducts.
    Subject to the amount of heat you need to deliver maybe an alternative would be a modified MHRV system with input and extract vents in each room, with sound attenuators all round and inline heaters on each flow. Or with larger pipework, as SteamyTea suggests.
    •  
      CommentAuthorSteamyTea
    • CommentTimeDec 29th 2017
     
    Double the pipe diameter and you can quadruple the mass flow rate for the same flow rate. Worth thinking about when doing some calculations.
    • CommentAuthordelprado
    • CommentTimeJan 3rd 2018
     
    <blockquote><cite>Posted By: SteamyTea</cite><blockquote><cite>Posted By: delprado</cite>anyone have a view on warm air heating?</blockquote>It can be noisy, and sounds from one area to another can be transmitted.

    I had forced air heating when I was in the US (Pennsylvania, so cold, hot, humid and dry, all in a year) and it worked well. Heated the place up fast, was stable and allowed controlled fresh air in as well.

    It does seem strange to me that we put in separate heating and MVHR systems in, why not combine the two. It does mean that you need room for larger pipework, but if you design that in from the start it should not be a problem.</blockquote>

    I note on PIV systems there is an element which can heat incoming air. Why can't you just do that on an existing MVHR without changing pipe work, on the assumption (having done the calculation) that your heating requirement upstairs is low and therefore it won't cost huge amounts to have this electricity produced hot air during the winter months?
    •  
      CommentAuthorSteamyTea
    • CommentTimeJan 3rd 2018
     
    Posted By: delpradoI note on PIV systems there is an element which can heat incoming air. Why can't you just do that on an existing MVHR without changing pipe work, on the assumption (having done the calculation) that your heating requirement upstairs is low and therefore it won't cost huge amounts to have this electricity produced hot air during the winter months?
    You may be able to, just depends how much energy you need to transfer and it what time frame.
    You are also limited on temperature. Too high and you start to get a smell from burning dusts. I have heard that 50°C is the upper limit.
    Really just a case of doing the sums and seeing what comes out.
    • CommentAuthortony
    • CommentTimeJan 3rd 2018
     
    So long as U values are below 0.1 air tightness near PH it might work,

    For the masses including all mainstream builders and the majority of eco houses and even some passive houses heat demand is so high that air cant shift sufficient quantities of heat
    •  
      CommentAuthordjh
    • CommentTimeJan 3rd 2018
     
    Posted By: delpradoI note on PIV systems there is an element which can heat incoming air. Why can't you just do that on an existing MVHR without changing pipe work, on the assumption (having done the calculation) that your heating requirement upstairs is low and therefore it won't cost huge amounts to have this electricity produced hot air during the winter months?

    I think on PIV systems it is there to bring the incoming air up to a reasonable temperature so as not to cause cold draughts. Some MVHR systems have a pre-heater to protect the heat exchanger from ice formation in cold weather. It is also quite normal to have a post heater to heat the air and thus the house (I have both).

    The difficulty with post heaters is as Steamy and Tony have said that ventilation air can't carry enough heat to warm normal houses because the temperature of the air has to be limited to 50°C to avoid burning dust smells. The heat demand of a PH is limited to that which can be supplied by the ventilation air.

    If you do your heat loss calculations, you'll probably find that the heating requirement is too much to be met by just the ventilation air. As a quick test, just buy some cheap halogen heaters and spread them around to see how much heat you need - don't forget to increase the requirement to adjust to the coldest temperature you want to cope with (-10°C or whatever)

    Forced air heating systems use much higher flow rates, to keep the duct sizes reasonable, and are consequently quite noisy. They also recirculate most of the air instead of using fresh air. My first house had a gas forced air system, which worked well for me as a single man out most of the day. Come home, turn the heating on, place warms up for the evening, turn the heating off and go to bed, similar in the mornng for a brief period.
    • CommentAuthordelprado
    • CommentTimeFeb 2nd 2018
     
    I'm now having a minor meltdown and feeling a bit confused with the renovation.

    Pricing up new flooring everywhere and underfloor heating - it all massively adds up. I am now considering super insulating the house outside (not completely easy as I have annoying chimney breasts) to try and get the wall u values to about 0.2, and together with a roof of the same and floors of 0.15, then surely I can get away without upstairs then?
    • CommentAuthortony
    • CommentTimeFeb 2nd 2018
     
    Nice idea ✋️
   
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