ASHP & triple glazing

[resybaby]

i'll go first. £22k

[AGT]

£13k. I will go and speak to my manager to see if I can do a better deal

[Joeboy]

While you guys are speaking to the manager and locking in a fine discount i'll try and get my head around heat loss through glazing.

"The value is quoted as watts per square meter per Kelvin (1°C = 1K) – W/m2K. For a double glazed window with a U-value of 1.4, this means that 1.4 watts will be transmitted per square meter for every degree of temperature difference between the inside and outside of the window."

Our main lounge has around 17 sqr mtrs glazing in it.

Based on Winter 23degs inside and -2 outside.

Double glazing at 2.6 and tbh I cant remember what standard i bought but it was defo at the lower end of cost scale would be 1,105W heat loss per hour.

Triple glazing at an optimistic primo 0.8 would be 340W heat loss per hour.

I ran the cost for an online triple glazed window in lounge diy style 2.2mtr x 1.2 mtr. £758!

I will have to go around and total up the glazing surface area now. Looks like triple v's double can be a massive difference maker.

SWMBO is right into it now, choosing handles n a'thing. There's no going back! Looking at those first pass figures I can see why Moxi mentioned the risk of overspeccing the ASHP.

[Countrypaul]

Double glazing at 2.6 and tbh I cant remember what standard i bought but it was defo at the lower end of cost scale would be 1,105W heat loss per hour.

Triple glazing at an optimistic primo 0.8 would be 340W heat loss per hour.

The heat loss is 1,105W - not per hour, you could say 1,105 Joules per second or 1.105 kWh per hour, similarly for your tripple just 340W.

You can use the degree days web site to get a feeling for how many days are how many degrees below your target (but choosing a suitable base figure is a bit hit and miss). That would allow you to see how much heat loss the difference between the 2 glazing systems would be over a year in terms of kWh.

Make sure the window figures you have are both Uw and not just Ug (Uw for whole widow, Ug for just the glazing).

[Joeboy]

Double glazing at 2.6 and tbh I cant remember what standard i bought but it was defo at the lower end of cost scale would be 1,105W heat loss per hour.

Triple glazing at an optimistic primo 0.8 would be 340W heat loss per hour.

The heat loss is 1,105W - not per hour, you could say 1,105 Joules per second or 1.105 kWh per hour, similarly for your tripple just 340W.

You can use the degree days web site to get a feeling for how many days are how many degrees below your target (but choosing a suitable base figure is a bit hit and miss). That would allow you to see how much heat loss the difference between the 2 glazing systems would be over a year in terms of kWh.

Make sure the window figures you have are both Uw and not just Ug (Uw for whole widow, Ug for just the glazing).

Thank you Paul, I knew where I was heading. Not so great at communicating it when excited.

Degrees days looks great, I will delve. Thanks.

The glazing area Incl the Velux units is 27.6 mtr sq

At a Uw value of 2.6 and at my Winter estimate i'd be losing 25 (temp difference) x 27.6 x 2.6 or 1.794kWh

At a Uw value of 0.8 and the same Winter estimate i'd be 25 x 27.6 x 0.8 or 0.55kWh.

1.244kWh difference across the unrelenting Winter scenario. Even allowing for a cool off over night on the WBS not being fueled that would still be over 20kWh per day of heat not lost through our double glazing. Wow, that is mightily impressive as is Fintray's current 5.7 cop.

[shirehorse99]

my price guess

windows - 16k
ashp - 8k after grant

have a check - some banks give grants if you have a mortgage with them - i know Lloyds do -

https://www.lloydsbank.com/mortgages/he ... nsulation.

[AGT]

Pretty sure on the green living forum, or one of them there was a glazing guy called Craig, lots of special sealing tape and expanding foam designed for window installs to help seal gaps properly, no point in sticking in Tg and have a huge poorly sealed strip around the window.

Will try and find the threads over the weekend

[Joeboy]

CR Smith have now joined Everest in falling on their face at the first hurdle (appointment etiquette). If they don't make it about you from the git go don't bother. A philosophy that has worked well when dealing with trades.

[Countrypaul]

The glazing area Incl the Velux units is 27.6 mtr sq

At a Uw value of 2.6 and at my Winter estimate i'd be losing 25 (temp difference) x 27.6 x 2.6 or 1.794kWh

At a Uw value of 0.8 and the same Winter estimate i'd be 25 x 27.6 x 0.8 or 0.55kWh.

1.244kWh difference across the unrelenting Winter scenario. Even allowing for a cool off over night on the WBS not being fueled that would still be over 20kWh per day of heat not lost through our double glazing. Wow, that is mightily impressive as is Fintray's current 5.7 cop.

Again, you have problems with the units, those should be kW not kWh, I hope you're not a scientist or engineer

Do a calculation on the external walls with and without insulation that should give you a much better idea of total heat loss though you also need to do floor and ceiling/roof if there are no living spaces below/above if you want to get a rmore accurate figure

When we renovated/extended we fitted 3g on the north windows, 2 of which are 1.5x 3 m but 2G everywhere else. This was partilly because tripple glazing noticeably reduces light transmission more than 2G, but also some doors got ridiculously expensive with 3G. All cavities were fitted with cavity closers and later te cavities filled with pur/pir all windows were taped using Siga Corvum 12/48 on the inside, foamed in and sealed with silicone sealant on the outside.

I was also told that the 3G were more expensive as more/larger hinges are needed on opening units and more fitters are required as the 3G units are much heavier than 2G. Ours were predominately wood and came to site aleady glazed. The others are aluminium 2 x 3m x 1.8m, & a bifold 3.5m x 2.1m.

My heat loss calculation for the house came out at around 8kW at -3 outside/22 inside, for 225m2.

[Joeboy]

The glazing area Incl the Velux units is 27.6 mtr sq

At a Uw value of 2.6 and at my Winter estimate i'd be losing 25 (temp difference) x 27.6 x 2.6 or 1.794kWh

At a Uw value of 0.8 and the same Winter estimate i'd be 25 x 27.6 x 0.8 or 0.55kWh.

1.244kWh difference across the unrelenting Winter scenario. Even allowing for a cool off over night on the WBS not being fueled that would still be over 20kWh per day of heat not lost through our double glazing. Wow, that is mightily impressive as is Fintray's current 5.7 cop.

Again, you have problems with the units, those should be kW not kWh, I hope you're not a scientist or engineer

Do a calculation on the external walls with and without insulation that should give you a much better idea of total heat loss though you also need to do floor and ceiling/roof if there are no living spaces below/above if you want to get a rmore accurate figure

When we renovated/extended we fitted 3g on the north windows, 2 of which are 1.5x 3 m but 2G everywhere else. This was partilly because tripple glazing noticeably reduces light transmission more than 2G, but also some doors got ridiculously expensive with 3G. All cavities were fitted with cavity closers and later te cavities filled with pur/pir all windows were taped using Siga Corvum 12/48 on the inside, foamed in and sealed with silicone sealant on the outside.

I was also told that the 3G were more expensive as more/larger hinges are needed on opening units and more fitters are required as the 3G units are much heavier than 2G. Ours were predominately wood and came to site aleady glazed. The others are aluminium 2 x 3m x 1.8m, & a bifold 3.5m x 2.1m.

My heat loss calculation for the house came out at around 8kW at -3 outside/22 inside, for 225m2.

Funny you mention that Paul. Thanks for laughing, great to see you present SO clearly and with such empathy.

Fortunately I can chuck money at it while caring not a jot as to kW, kWh. In the form of money earned while engineering across the world (imagine)?. Might even be triple what I need.

Manners eh? I'll have to tripple up on them while checking if I'm partilly aware of my own communication skills. Thanks for the input though.

I try to not get hung up on these things while remaining partilly polite to those around me. Although I find it mildly irksome. That's irksome with an e. As in the, not th.

I'll just do the lot in triple and enjoy the benefits in any unit of value you'd care to mention (again).