Heat loss - noticeable improvement in still-air conditions.

My house is now very well insulated and reasonably well draftproofed.

(300mm solid masonry + 100mm celotex walls,

400mm fibreglass loft insulation + breathable membrane under slates, double glazing, 4/16/4 sealed units, openers seal well, suspended timber floors, no underfloor insulation, but ground-level vents s heltered by nearby fences)

It's noticeable how much more heating is needed on cold and windy days, com pared to very cold but still days (like today).

Now some of that increased heat loss will just be air current across the wh ole structure - but I suspect some of it is drafts.

The two obvious ones are the fresh-air vents for the woodburner and the cen tral heating boiler.

Both are open flue appliances, through masonry chimneys, with stainless ste el liners about 7.5m long - so I don't think much warmth is lost through ea ch flue whilst they're not operating.

The only other two obvious sources of heat loss due to drafts, are the fron t doors (which could seal a little better), and the bathroom vents. The lat ter is a whole-house system with some length to the pipework, so I don't su spect much loss through that either.

So my first question is - where/how to look for remaining heat losses assoc iated with windy weather?

And secondly, anything that can be done to reduce the drafts through the ap pliance fresh-air vents?

Reply to
dom
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google black hole ventilator other makes may be available.

On the appliances, all the air inlets on the woodburner could be closed (assuming it's not lit!) so only minimal air is drawn up it's flue. Can't do that with the boiler though.

I think your biggest loss now will be down through the uninsulated and well ventilated floors.

Reply to
Dave Liquorice

look for microgaps that lead into any open fibre insulation areas. A breeze through rockwool destroys it.

Lofts - ventilated lofts are disasters areas in wind even with inches of rockwool

Reply to
The Natural Philosopher

(300mm solid masonry + 100mm celotex walls,

400mm fibreglass loft insulation + breathable membrane under slates, double glazing, 4/16/4 sealed units, openers seal well, suspended timber floors, no underfloor insulation, but ground-level vents sheltered by nearby fences)

It's noticeable how much more heating is needed on cold and windy days, compared to very cold but still days (like today).

Now some of that increased heat loss will just be air current across the whole structure - but I suspect some of it is drafts.

The two obvious ones are the fresh-air vents for the woodburner and the central heating boiler.

Both are open flue appliances, through masonry chimneys, with stainless steel liners about 7.5m long - so I don't think much warmth is lost through each flue whilst they're not operating.

The only other two obvious sources of heat loss due to drafts, are the front doors (which could seal a little better), and the bathroom vents. The latter is a whole-house system with some length to the pipework, so I don't suspect much loss through that either.

So my first question is - where/how to look for remaining heat losses associated with windy weather?

And secondly, anything that can be done to reduce the drafts through the appliance fresh-air vents?

Probably your floor. Also there are likely to be gaps between floor and skirting. You need to get under there with some rigid foam well glued in with aerosol foam.

You can get room sealed woodburning stoves these days.

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Reply to
harryagain

I had under floor insulation installed in my 1897 house in April this year. The exercise was paid for entirely by City of Edinburgh Council. The heat loss improvement will be measured best by changes in gas consumption but an effect we noticed all through the summer was the much reduced air movement. We used to know if it was windy outside by the air moving in the house. That is no longer the case. It took 2 men 2 hours to do 70sq metres of floor.

Reply to
Geoff Pearson

Good grief what did they do? Drill a hole and squirt in foam?

Sounds like a botch job to me.

Reply to
Dave Liquorice

Presumably though for an open flue appliance there combustion air ventilation? (if not, be careful not to seal up too many drafts!)

Feeling for air currents would be one option. A IR thermometer will allow you to see the difference in surface temperatures as conditions vary from one day to the next.

Not while they are open flue devices.

The boiler at some point in the future will presumably get replaced with a balanced flue model...

Reply to
John Rumm

In article , snipped-for-privacy@gglz.com writes

For conventional coal fire flues it's reckoned that you lose about 1kw up each flue. Perhaps less for closed appliances but air used to howl through my closed front gas fires when off before I decided to scrap them and close the flues (yes I know there should be a vent).

Best example was when I was fitting a 4" stainless flue to a tenement chimney and planned to confirm which flue was ours using a burning paper in the hearth and checking for smoke/feeling the heat at the room level. There was so much heat coming up from the other flues that it took quite a while to determine which was ours and not one was an active flue.

I don't think the length of the flue makes any odds, hot air rises and chimneys are designed to draw and draw, the example above was on a 24m flue.

It does sound like you have a draft problem.

I think fingertips or hairs on backs of hand are quite a good indicator, they feel the cold and relatively small flows. Obviously, doing it on the windiest day possible will yield the best results.

The official leakage tests block up a doorway and put a fan in it, the pressure across the fan indicates how much air is leaking out of the room/house.

Typical areas to look at are gaps between floor and skirting where a 4mm gap open to the underfloor in a decent sized room is equiv to leaving a sash window open by 80mm.

A low IR thermometer reading on bits like skirting might indicate a lot of cold airflow behind.

Not really if you intend to use the appliances.

Reply to
fred

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