PHPP for part O

[G and J]

11 minutes ago, ADLIan said:

U-vals are only quoted to 2 decimal places so still 0.18! Even if to 3 places a difference of 0.003 W/m2K is unlikely to impact overall energy assessment

You sweet talking thing you! Lol

 

OK, what .035 product are you thinking of?

[MikeSharp01]

I think there are quite a few in that range.

 

• Mineral wool: 0.030–0.040 W/m²K 
   
• Expanded polystyrene: 0.030–0.038 W/m²K 
   
• Extruded polystyrene: 0.028–0.038 W/m²K 
   
• Polyisocyanurate (PIR) and polyurethane (PUR) foam: 0.022–0.028 W/m²K 
   
• Cellulose fiber: 0.04–0.05 W/m²K 

[G and J]

Ok, just googled knauf frametherm 035 and that is a lot cheaper than the nyrock.  Is there a downside?  Are there other products I should also look at?  Will it save me enough to pay for my part Oh stuff?   :-0 

[G and J]

1 minute ago, MikeSharp01 said:

I think there are quite a few in that range.

 

• Mineral wool: 0.030–0.040 W/m²K 
   
• Expanded polystyrene: 0.030–0.038 W/m²K 
   
• Extruded polystyrene: 0.028–0.038 W/m²K 
   
• Polyisocyanurate (PIR) and polyurethane (PUR) foam: 0.022–0.028 W/m²K 
   
• Cellulose fiber: 0.04–0.05 W/m²K 

So for stuffing in a frame mineral wool is the winner!  Woo hoo.

 

 

[MikeSharp01]

1 hour ago, G and J said:

So for stuffing in a frame mineral wool is the winner!  Woo hoo.

 

The fitting won't be easy, we had it as an option but chose the blown cellulose in the end. Although there are some places we used it because the space was too small for blowing. 

[G and J]

20 minutes ago, MikeSharp01 said:

The fitting won't be easy, we had it as an option but chose the blown cellulose in the end. Although there are some places we used it because the space was too small for blowing. 

Umm, why won’t the fitting be easy?

[MikeSharp01]

Because you have to fill all the voids. If you have flat timber frames it is easy but then you have massive cold bridges on the outside. We have I joists so the void is odd shaped - don't know what you are considering. Filling cavities is easy, just drop the batts in as you go. 

[Susie]

2 hours ago, G and J said:

I completely get the coffee in bed with a view that’s what we will have too

bedroom window is 1500mm x 1500mm tilt and turn inwards £1500 alu wood triple glazed from norrsken. In reality I can see it never open on turn possibly a bit on tilt. It got me a pass though. 
try it tilt only first just to see if it passes

 

you def have cross ventilation for example a studio apartment with only one ‘clock face’ doesn’t have cross ventilation. 

you actually have a similar problem that I did either make some fixed windows open or add some Velux as they open massively (90% can’t remember the allowances) and you can put them on the North side possibly. 
 

when I did mine it was still very new and the dynamic modelling was either expensive to do or the altered aspects it could have suggested costly or the wait time for some one to model it meant my time on the spreadsheet was worthwhile. 

[SteamyTea]

11 hours ago, MikeSharp01 said:

 

• Mineral wool: 0.030–0.040 W/m²K 
   
• Expanded polystyrene: 0.030–0.038 W/m²K 
   
• Extruded polystyrene: 0.028–0.038 W/m²K 
   
• Polyisocyanurate (PIR) and polyurethane (PUR) foam: 0.022–0.028 W/m²K 
   
• Cellulose fiber: 0.04–0.05 W/m²K 

Something don't look right there.

Are they k-values W.m^-1.K^-1

 

100mm of mineral wool would have a U-value of .38 W.m^-2.K^-1

 

 

[ADLIan]

Numbers look right for conductivity in W/mK.

[SteamyTea]

29 minutes ago, ADLIan said:

Numbers look right for conductivity in W/mK.

Yes, but the units are W.m^-2.K^-1 which is U-Value, unless the thickness is 1 metre.

Mineral wool: 0.030–0.040 W/m²K 

 

[ADLIan]

Units are wrong then. Should be W/mK.