I got a cold call from one of the Solar Co's yesterday, "not selling
anything Sir but just checking if you qualify for the grant" (or
incentive, I wasn't really listening) ... and according to the guy who
called back later I was. ;-)
However, after his spiel I explained I'd been there before and
obviously had a rough idea of the numbers ... then we accidentally got
That got me reading the recent 'FIT Slashed' thread, that covered
insulation amongst other things and got me thinking about what I could
do here (1897, solid 9" brick EOT 3 bed).
And that got me thinking about ventilation. If we are supposed to
exchange the air every so often, I'm not sure at what point 'good
insulation' is counteracted by all the cold air coming in from the
So, how do we deal with that? Is it an issue? Why isn't there more
talk of heat exchangers (I believe there has been some talk but not
Will that be the next top seller or scam, picked up by the Solar Co's?
Cheers, T i m
Modern builds (esp in the eco & part funded sectors) are fitting air
source heat pumps, heat exchangers for ventilation (IIRC Part L decrees
it now anyway) and all sorts of gubbins. I was on site at Kevin McClouds
development in Swindon the other month and they'd gone for the ASHP in a
big way to the extent of not laying on gas.
Where are we going and why am I in this handbasket?
On Fri, 04 Nov 2011 00:09:35 +0000, Scott M wrote:
ASHP isn't the same as a heat exchnaging ventilator. The first
actively pumps heat from a source into the building. The second uses
something similar to a balanced flue where air is drawn in from
outside and is heated by the warm air being expelled. They generally
run at a low level all the time to provide background ventilation but
if the humidity rises go into a "boost" mode.
Likewise, but it's not about what's right for the buyer, it's about
hype, developer's margins and money in the endorser's pocket. Celeb chef
gets a few bob for their name on pans and knives but can you imagine
what you could make off the back of a housing development?
Air doesn't take that much energy to heat it compared to what you
will have leaking out through the walls. 9" solid brick loses about
2W/m^2/K or about 20W/m^2 the room at 20C and 0C outside.
Being end of terrace you'll have acres of external wall. Bunging some
internal insulation on, even just 25mm foam bonded to 12.5mm
plasterboard will make a very noticeable difference to comfort and
energy bill. Trouble is doing it is very disruptive unless you make
it part of the decoration schedule.
On Fri, 04 Nov 2011 08:43:09 +0000 (GMT), "Dave Liquorice"
Yup, and a road wide gap to the next terrace so normally a nice
cooling breeze over the wall. It also gets the sun on it for the best
part of half a day so can also be quite a nice storage rad. ;-)
Well, we haven't really finished decorating the hall yet so that
wouldn't be a real big issue, however when the wall was re-plastered
it was done with some plaster (or bonding possibly?) that was supposed
to be better thermally? I'm guessing it wouldn't be anywhere near 25mm
of foam though?
If fitting an inner lining we would have to incorporate the stairs and
maybe flare it off near the front door but I can't see it being a real
However, we don't have central heating either so when it gets real
cold we just shut the lounge door and have the gas fire on a trickle
and that seems to do the job (for us).
Another job I ought to tackle is some sort of insulation / sealing on
the loft hatch as that is just a hinged sheet of 1/2" ply. With the
loft ladders above I'm not sure how you would provide insulation
without it getting in the way. Is there a nice ready-made (but
customable size) solution out there ... like a sealed DG window unit?
And if I do seal everything up ... would I then need air heat
exchangers to deal with the condensation? ;-(
When I bought this place over 30 years ago we never suffered with
condensation but then it had the rattly sash windows as well. It was
handy in a way as you already had your coat on if you decided to go
Cheers, T i m
p.s. The Mrs is *still* going through 'the change' and so is in no
real rush to have this place any warmer.
The foam rubber strip sold for windows should do as a seal unless it is
a rattling good fit all round, and the foil backed polystyrene foam sold
for putting behind radiators (the flat thicker stuff not the thin rolls)
is about the most effective insulator in a small space. The aluminised
bubble wrap might be better for the loft door though.
There was room on mine for a 2" slab of insulator which whilst nothing
like as good as the full 12" is a lot better than nothing!
gap all round) but straight into the 500W x 800L box I made within the
joists when I opened up the hatch originally (as in 30+ years ago). It
uses one of those push open - push closed type catches so there is
nothing behind the flap as such (as I didn't want to make the aperture
any smaller for getting stuff in and out). That said there is a small
(15x15) bead round the inside at the bottom (that 'frames' the closed
flap) that could come out if a re-design made getting it sealed /
insulated easier (I think I put that in to give any architrave
something more substantial to attach to).
I can see a block of that stuck to the back of the flap / door could
be easy / good but was probably more concerned re draughts and the gap
compared with the insulation of the wood / flap?
That's why I was wondering if there was some sort of ready-made door
that you could fit 'over' the whole aperture (so on the landing
ceiling if you like) that wouldn't require any reduction to the
aperture whilst providing some reasonable insulation. The ceilings are
reasonably high so even if it stuck down a few inches it wouldn't be
an issue (and no one here would care less what it looked like). ;-)
At 6'2" and with gibbon arms I can stand and reach the door to open /
close it and a little spring jump lets me grab the ladders. ;-)
Yup, that could work (certainly be better than the plain wood). I'm
thinking if there was to be a seal then some of that brush type stuff
fixed to the back of the flap might be better than nothing and not
restrict the aperture at all?
I could get a couple of large plugs of polystyrene in there
(overlapping or summat) that are just a good fit so stay there on
their own (so over the flap but under the ladders) but it wouldn't be
very convenient to use (and daughter 'hates' the noise and dealing
with polystyrene). ;-)
Isn't there something in kit form with all the required seals and
insulation out there? Like the roof light kits?
Ideally it might be a rectangular angle frame (8mm thick plastic?)
that would sit in the hole and on the ceiling (al la architrave) but
also allow for a good insulated door with proper rubber airtight seals
(al la double glazed door / windows)? Such things must exist?
Cheers, T i m
Right. So decent ventilation for a Victorian terrace is not a
significant cause of heat loss.
... having said that, for a house built to the Passivhaus standard
(MASSIVE amounts of insulation, and airtight when ventilation is
switched off) ordinary ventilation would be a huge heat loss, and they
need heat exchanging ventilators. (They are sufficiently insulated
that they don't need a heating system - they just use the heat from
On Fri, 4 Nov 2011 07:40:51 -0700 (PDT), Martin Bonner
.... so there would be no real / tangible advantage using (passive)
heat exchangers in any ventilation?
We have even noticed that is this place when there are 4 people and 4
computers on, plus a TV etc.
So, given only the downstairs bathroom (Nth facing extention to the
rear addition) is 'modern' construction (breeze blocks, insulated
cavity, old stocks) and there isn't much in the way of other external
wall facing North that isn't broken up with double glazed uPVC windows
or doors, how much advantage would we gain from internally insulating
the unheated flank wall or sorting the loft hatch do you think
Our bedroom (Sth facing) is heated by one 'intelligent storage rad, as
is the bathroom. Daughters exposed_on_3_sides, Nth facing box room has
a balanced flue, convection gas fire (that can get too hot on setting
1 of 3). The lounge has a 3 burner wall mounted gas fire that is
rarely on full on 1 (normally thermostatically turned down once warm).
I don't bother heating the kitchen since I bought her a nice winter
We also have an electric shower and a Mulit-point gas water heater for
the bath, basin and sink (we mainly shower and try to do so during the
E7 time). The dishwasher and washing machine are cold-fill and along
with the tumble dryer are mainly used on E7.
It can get a bit nippy between the warm zones but we are used to it
and mankind has survived for millions of years with less. ;-)
Cheers, T i m
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