New Project - Garden Office - Research Stage, Help Needed!

[Cliffoshay]

O.K.

I've said ( not on here but I have ) I want to try to be a better, nicer, more patient person so this seems to be a good opportunity to try out that new resolve !

The problem I have is - bluntly - you don't know a lot but wish to question everything, even if you don't then understand the answer or the ramifications.

Help me to get to an answer for you and answer the following.

1) Where do you live in UK
2) Exposed area or town ?
3) How much heat in kW do you envisage needed to heat shed ?
4) What is your total budget and how much is for insulation ?
5) What percentage of shed will be doors/windows ( big heat-loss items )
6) How many watts of energy will computers/printers/anything in shed put out ?
7) How high will walls be ?
8 )What is lowest temp you have had during day this winter ?

I appreciate that.. feel like a guinea pig!

Here's my answers:
1)Devon
2)Town
3)Not sure as will have 2 PCs and the generate some heat (I very rarely have the heating on in the office I currently use in the house)
4)I'm hoping I will be able to achieve something for £2k - but until I have my head around the design I don't know how realistic this is. 20% 25% for insulation.
5)UPVC French doors and one or two windows so 15 - 20%?
6) 2x PCs 350w & 450w power supply, 2x laser printers, FAX machine, low energy spotlights couple of desk lights... and probably a 2 kw heater
7)Max 2.5m sloping to 2m
8 ) -3c

 

[mointainwalker]

Tomorrow .

I have never said anything about answers to forum taking precedence over comfy sofa, fire , lady and red-wine !

 

[Cliffoshay]

I should hope not! Have a glass for me... I'm not allowed to have a bottle open as my pregnant wife can't partake and want's me to suffer with her. It's going to be a long 8 months!!!

Enjoy

 

[mointainwalker]

If 100 mm wool and your approx construction, the U value is about 0.35
2) With 150 mm ........................... 0.25

This means you lose 0.35 Watts per hour per m2 per degree diiference ( if 18 c inside and -3 c outside that is 21 degrees of difference ( usually called degrees K )

To allow for doors and windows which are much worse, let's round that up to 0.40 and 0.30.

With 21 degrees K , you lose 21 x 0.40 = 8.5 W per m2 per hour.

If 30 m2 of wall( using your smaller sizing ) then you only lose 250 W per hour under worst conditions.

If roof is 10 m2 then that;s another 120 W.

Floor losses are different because as long as you can prevent draughts blowing in, losses will be smaller as heat rises away from the floor.

How you insulate the floor will be tricky as you need to prevent rodents being able to burrow in and nest ( and eat your cables )

These figures seem astonishingly low ( always do ) because they assume no air-leaks which quickly increase the heat-loss.

I haven't bothered to calculate the 150 mm as I think the 100 mm is good enough and will save you bother with the walls.

Don't forget to put a vapour-barrier ( poly sheet )between the plasterboard and the insulation.

 

[bolst3r]

sorry to carry on from this but is there a particular wool insulation you would recommend? I see you say Knauff fibre wool but I can't find this in 100mm for walls, only 90mm unless I go for roof insulation but I assume this is a different product?