Non-motoring > 'blown' double glazing	Miscellaneous
Thread Author: bathtub tom	Replies: 24

New Wed 26 Feb 25 16:23   'blown' double glazing - bathtub tom

One of my bathroom windows is 'blown'. It's obscure glass and SWMBO hadn't even noticed until I pointed it out. Neighbour has said because the vacuum is gone, it's not as efficient, they also said it's allowed the argon gas to leak out. My reply was if the vacuum's gone, then the argon's bound to leak out. They also said a 'blown' dg unit's no more efficient than a single glazed unit. I think they're talking out of their arris. Does anyone know where to find the relative U values? Reply to this message | Report message

New Wed 26 Feb 25 16:34   'blown' double glazing - Bromptonaut

It'll be less efficient than when it left the factory but two panes with still air between will have significantly better functionality for insulation than a single pane. Biggest issue for me would be condensation between the panes. Reply to this message | Report message

New Wed 26 Feb 25 16:37   'blown' double glazing - bathtub tom

>> It'll be less efficient than when it left the factory But is it? >> Biggest issue for me would be condensation between the panes. It's obscure glass and you have to look very close to spot it. Reply to this message | Report message

New Wed 26 Feb 25 16:43   'blown' double glazing - CGNorwich

If your're not fussed then leave as is. If you are fussed get a new pane. Reply to this message | Report message

New Wed 26 Feb 25 16:44   'blown' double glazing - smokie

My new neighbour in the house behind ours has obscure glass on hi bathroom window. His shower puts him right next to the window, and he has no blinds or curtains. Rest assured, you don't have to look very close to spot it!! He's certainly been blessed!! Unfortunately there doesn't seem to be a woman in his life... :-) Reply to this message | Report message

New Wed 26 Feb 25 18:21   'blown' double glazing - Zero

When the seal between pains has just gone, it wont materially be less thermally efficient. When the moisture gets in and cant escape, which inevitably it will, then it will be considerably less thermal efficient, and when the inevitable moulds and stuff grow, it will be worse. As well as unsightly. Reply to this message | Report message

New Wed 26 Feb 25 19:36   'blown' double glazing - bathtub tom

>> When the moisture gets in and cant escape, which inevitably it will, then it will >> be considerably less thermal efficient, But why? There's still an air gap. Reply to this message | Report message

New Wed 26 Feb 25 21:07   'blown' double glazing - Zero

>> But why? There's still an air gap. Because its no longer dry inert air, its now moist air, growing other matter, and is more thermally conductive. Reply to this message | Report message

New Wed 26 Feb 25 16:50   'blown' double glazing - Manatee

I'm not sure why it would be materially less efficient. It's still mainly air in there. Was it ever argon? If it had been a vacuum...but I don't think that's the case! Reply to this message | Report message

New Wed 26 Feb 25 18:22   'blown' double glazing - Zero

>> I'm not sure why it would be materially less efficient. It's still mainly air in >> there. Was it ever argon? It should have been an inert gas of some kind. Reply to this message | Report message

New Wed 26 Feb 25 20:13   'blown' double glazing - CGNorwich

Argon is denser and more thermally efficient that air. Reply to this message | Report message

New Sun 2 Mar 25 23:28   'blown' double glazing - Bobby

On a related subject, how many folk have radiators on in their bathrooms but the windows ajar or open? Hate having a shower in a cold bathroom but the window does need to be opened…. I probably lose most heat from that bathroom window ! Reply to this message | Report message

New Mon 3 Mar 25 08:44   'blown' double glazing - Terry

>> On a related subject, how many folk have radiators on in their bathrooms but the >> windows ajar or open? >> Hate having a shower in a cold bathroom but the window does need to be >> opened…. >> I probably lose most heat from that bathroom window ! A fan operated when the light or shower are switched on is the solution. It will draw in warm air from the rest of the house whilst in use and expel moist air to reduce mould build up etc. It would normally have an integrated timer to ensure it goes off (say) 5 minutes after the lights go off to get rid of remaining moist air and avoid further heat loss. Reply to this message | Report message

New Mon 3 Mar 25 09:13   'blown' double glazing - smokie

I have one (a Vent-Axia Svara) which i triggered by light, presence or humidity. The fan speed increases as, for instance, the humidity increases and so on. It runs till whatever triggered it has returned to the threshold you set. It really is more effective to open the window to clear the steam or smells!! Bathroom rads don't chuck out much heat in the scheme of things... (I also have mine on trickle mode where the fan is running fairly slowly all the time, to keep the air fresh. Not sure of the value of that either really but it costs pence to run. You can set "quiet periods "so it doesn't kick off in the night - not that it is *that* noisy. Reply to this message | Report message

New Mon 3 Mar 25 09:31   'blown' double glazing - Bromptonaut

We have fans in both our ensuite and the family bathroom though both are 'plain vanilla' models with a seperate switch and no timer. If it's really cold outside I'll shut the window while showering but ensure it's opened again afterwards. Condensation from bathrooms and drying clothing is a major factor in allowing mould etc to develop on walls. The need to at least crack open windows to allow proper ventilation cannot be over emphasised. Reply to this message | Report message

New Mon 3 Mar 25 10:24   'blown' double glazing - Manatee

>> (I also have mine on trickle mode where the fan is running fairly slowly all >> the time, to keep the air fresh. Not sure of the value of that either >> really but it costs pence to run. You can set "quiet periods "so it doesn't >> kick off in the night - not that it is *that* noisy. That is probably ideal. You need heat and ventilation to keep mould at bay. Mould is a scourge now that everybody is insulating and draughtproofing while keeping their houses cold to save on energy. I'm not suggesting you all whack in a MVHR, but ours runs all the time throughout the house. We don't have howling fans, just the constant silent extraction. Any condensation in the bathrooms is gone half an hour later. If I have had a long shower I press the boost button and the MVHR runs at 60% for half an hour rather than the normal 43%. 'Normal' shifts a houseful of air about every 2.5 hours. Having a trickly bathroom extract like yours must be the best thing in the absence of MVHR. Reply to this message | Report message

New Mon 3 Mar 25 14:37   'blown' double glazing - zippy

I have just been quoted £642 to have an extractor fan fitted to the bathroom! It's a ceiling one. Connected to the lights and to the consumer unit. The vent will be a rooftile with a vent. Seems expensive to me. Reply to this message | Report message

New Mon 3 Mar 25 16:11   'blown' double glazing - Bobby

Scaffolding involved? Reply to this message | Report message

New Mon 3 Mar 25 20:57   'blown' double glazing - zippy

>> Scaffolding involved? >> No. Ladder. Split level bungalow. Reply to this message | Report message

New Mon 3 Mar 25 21:23   'blown' double glazing - CGNorwich

Doesn’t seem particularly high - expect £60 to £100 per hour labor depending where you live but only way to know if it’s reasonable is to get few more quotes. Reply to this message | Report message

New Mon 3 Mar 25 21:32   'blown' double glazing - zippy

>> Doesn’t seem particularly high - expect £60 to £100 per hour labor depending where you >> live but only way to know if it’s reasonable is to get few more quotes. >> In the process of doing that. £60-100 an hour! I'm in the wrong job! :-D Reply to this message | Report message

New Mon 3 Mar 25 22:47   'blown' double glazing - smokie

I think if you are paying £60 - £100 an hour for trades then you are being taken for a mug. Wokingham is quite expensive but about the most expensive day rate out of the electricians, roofer, K**************, plumbers, painters and plasterers I've hired in the past year was £325. None I had was more than that. My mate about 25 miles south of us (i.e. still in not-so-cheap territory) reckons most of those trades are £250 or under for a day and he has had tradesmen in virtually every day for over a year on major extensions. I could believe £150 for a mornings work, as often the tradesman won't get two jobs in one day, and they've got mouths to feed. Reply to this message | Report message

New Mon 3 Mar 25 23:06   'blown' double glazing - zippy

That seems a fair rate. I'm on the South East coast, so prices should be lower. Reply to this message | Report message

New Mon 3 Mar 25 22:23   'blown' double glazing - bathtub tom

My fans either blow out through the wall (4" hole), or ducted into the loft and into a vent in the soffit. Reply to this message | Report message

New Mon 3 Mar 25 23:12   'blown' double glazing - zippy

>> My fans either blow out through the wall (4" hole), or ducted into the loft >> and into a vent in the soffit. >> The only possible hole in the wall is at the front of the house and that's not acceptable. I have been told that soffit vents no longer meet building regs. Reply to this message | Report message