Cognis0

Somerset, where they make cheese and cider..!

We are in Somerset, not renound for being the coldest part of the country! The property should have good thermal mass and good thermal gain from the large south-facing windows. If it had an uninsulated concrete floor I could understand that might "suck" heat out of the building, but it has a timber floor that is warm to the touch and drafts are conspicuous by their absence. But I do know other people who have complained about 1960s properties being very cold ~ I just can't work out why!

Good comments, thanks. The house seems to be bone dry with no evidence anywhere of any water ingress. There are no perceptible drafts, although when the Thermabead was installed they insisted on installing trickle vents in the windows. We have just come back from a week away, and whilst we left the trickle vents open the bed linen does seem to be damp ~ so this needs further investigation.

In June we bought a 1960s bungalow as a project with major works planned aiming at EnerPHit type standards of insulation (although we are unlikely to be able to achieve that). In the meanwhile, we are living in the property until the work is carried out next year. We have been cold in the house since we moved in ~ even in the middle of summer the house can hardly be described as warm, and the towels never seem to dry out ~ even in July! Our gas boiler was condemned a few weeks ago and we are in the process of having this replaced as we can't live through the winter without it and it may prove useful for top-up if the planned heat pump can't cope with deep winter conditions. So the house has had no heating for the best part of a month and having just returned from holiday abroad this place is absolutely freezing ~ its like walking into a fridge and the bungalow seems to be colder inside than out. The construction is 225mm natural stone external leaf with nominal 50mm cavity and 100mm Thermalite type block inner leaf. The floor is raised timber and traditional roof construction with about 100mm glass fibre insulation in the loft (1980s?!). There is 18m2 of large south-facing picture windows which are double glazed as they are throughout with reasonable quality windows and no signs of any drafts. We are planning fairly substantial internal wood fibre insulation to the walls etc, but as an interim measure, the cavity has been filled with Thermabead. This is the newest property I have ever lived in, but is most definitely the coldest by a very long way. I recently moved from a Georgian-era house with 6 sets of single glazed drafty French doors, but it is far colder than that (and I don't recall putting the heating on before about mid-October). It is a mystery to me why this house is so cold and I am concerned that normal heat loss calculations will not be accurate. Can anyone shed any light on why this property is so cold? It's miserable here and we can't wait for the replacement boiler to be fitted ~ as a long-term project to produce a warm, comfortable, economical and attractive property we are beginning to lose faith. I've just checked ~ 5pm on Sunday thermometer is reading 13 degrees C. I'm surprised its that warm! I welcome your comments..

Thank you @joe90 and @SteamyTea

Hi Jeremy, I'm visiting this one again... I'm still intrigued by the "thermodynamic panel" concept and would like to start engaging with some of the suppliers. Other than asking for their COP rating, what other "meaningful data on performance" would you suggest I seek from them? Many thanks, Tony

Thanks guys, this is great, real life, information now steering me in the right direction ~ exactly why I chose to join the forum!

Much research still to do but.. (and of course relying upon the accuracy of material I have found available/advice received).. PV-T panels run cooler, and therefore PV more efficient I can cope with just one or two rads in the house Glass foam granulate raft, possibly with cork/lime screed (UFH could sit on top of this of course, if needed) This is the first negative I've heard regarding Magic Box/Energie type systems.. Thanks for comments

Thanks for your comments gentlemen, particularly useful @Jeremy Harristo learn about Spring/Autumn overheating and Sage Glass, although we are not planning to have large expanses of glass which could well be a short-lived fashion. This is clearly a complex subject which requires much thought and research. At this early stage my wall/roof build-up is showing about 0.105 W/(m2K). Agree that all panels should be steeply sloped for winter sun angle. Whilst solar thermal is attractive on paper, particularly in PV-T format which provides more efficient PV, I accept it is flawed (my brother who works for Honeywell was called to a property where the pump had failed and steam was being emitted from several locations!). DHW and space heating could be supplied from a single source, and I know of systems where the hot flows through the DH cylinder to the central heating rads, so DHW is always prioritised. Potentially this could work with low temperature hot, it just needs to be designed properly. I'm not convinced about UFH in a passive house, which seems like a sledgehammer to crack a nut when a couple of low temperature radiators in strategic locations should be adequate? (also I'm not planning to have a concrete floor slab). I also quite like the sound of Magic Box thermodynamic "solar" panels, which I suppose are just simple heat pumps with some solar capture. Simplicity seems to be the byword for this product, with little maintenance requirement. It seems these are only used for DHW, but I wonder if they could be used for space heating when the demand will be small. But presumably they don't offer a reverse cycle mode to deal with cooling requirements. More research needed!

I'm not sure if this is the right forum, but here goes... I'm planning a Passivhaus and I'm giving thought to DHW and (occasional) space heating which even super-insulated houses will need in the depths of winter. Because the space heating requirements of passive houses should be quite small it would seem to me most sensible to deliver this via warm air through the MVHR system. There are proprietary "Heat Pump Ventilation" systems such as Genvex and Ecocent which appear to use the warm ventilation exhaust as the heat source for the heat pump. These seem to also offer provision for DHW, but I have not found much information about them on-line, and I am sceptical about this as a solution. Because we will install PV anyway, a better heat source to my mind would be solar thermal via PV-T combined panels. On most days this would produce adequate quantities of hot water for DH, and with a buffer tank this should also provide a source for a heat pump, if such a thing as a water to air heat pump is available? Thanks for reading and comments welcome, particularly from those who have explored solutions along these lines...