How would you insulate this? - Attic cold water storage tank

MiketheMechanic

Hi all.

I had a BER assessment done recently. The assessor was very helpful and pointed out a list if things that I could change to improve the energy efficiency of my home.

One of the things he said was that the insulation of the attic cold water storage tank should be improved.

The tank is 158cm x 46cm x 50cm approx, so I guess it is a 60 gallon tank in the attic of a 2 storey house.

It is fed by the mains and then supplies the cold water feed to the hot water cylinder in the hot press on the first floor, as well as the cold water taps for sinks and bath on the first floor.

It also supplies the cold supply to a Mira Event Thermostatic pumped shower (great shower!) on the first floor.

As you can see in the photos, currently, there is some fibregalss insulation taped around the tank.

The lid is a makeshift one made from corrugated plastic board.

So what's the best way to insulate a tank like this?

Would lagging jackets for a hot water cylinder work and hos should they be fastened to the tank?

Is there a better lid that can be sourced? Looks like Tyrrell tanks are out of business.

Any suggestions welcome. Thanks

dathi

tape kingspan/ xtherm type insulation together to form a box around the tank and use same for lid

DublinDilbert

make an insulated lid from the foil back PIR insulation (might find a big enough piece in a skip), then run the fibre glass insulation up one side and down the other

MiketheMechanic

I got a suggestion of lagging jackets (like the ones used for old copper cyilinders). Has anyone ever used this.

Silly question perhaps, but where could I buy foil backed Kingspan? Do the likes of Woodies carry it? Or would I have to buy a massive slab of it?

Could I use rockwool or mineral wool around the tank? I'm not a big fan of handling fibreglass, even with PPE. Always seems to get in my nose/eyes/lungs too.

MtM

10-10-20

Foil backed PIR insulation could be used except it's expensive and is rigid and could be tricky to get a good seal at the corners. Have a look in a builder's merchant and you'll see 20mm and larger thicknesses which are in 2.4m * 1.8m sheets.

There used to be an insulation product which was glasswool in a foil bag, I think B&Q did it... but I don't see it around now. It would have been ideal for this use.

Another product which you could use is B&Q's polyester based insulation. It's much easier to handle than glass/rock-wool and will be more robust too.

https://www.diy.ie/departments/diall-insulation-roll-l-6m-w-0-37m-t-100mm/3663602481812_BQ.prd

Sleeper12

I don't have any photos but basically you shouldn't be able to see the tank at all. It should be totally insulation. Insulation should be inside a material like plastic.

MiketheMechanic

https://www.boards.ie/discussion/comment/121621231#Comment_121621231

Actually, that looks like a very nice product, I think this polyester insulation will work for around the tank. I can pick some up at B&Q.

I need to come up with a practical lid that will:

i. support some insulation going over it.

ii. keep dust and deris out of the tank.

iii. Not foul or get mouldy in this environment.

The existing lid is a makeshift one made from corrugated plastic board. (actually part of an old election poster thet blew into our yard years ago 😀)

It works to keep out dust but is a bit too light to support any additional insulation.

On the plus side - nothing nasty grows on it.

I assume a lid of plywood or OSB would be unsuitable? Can anyone suggest a material and a place to buy it that I could use to make up a lid

The lid has to accomodate a swan neck pipe which I assume is the emergency overflow from the copper cyliner downstairs.

Suggestions please?

MtM

10-10-20

Would two layers of black corriboard under PIR board suffice?

https://tjomahony.ie/black-floor-protection-sheet-corriboard-8-x-4-x-2mm-33bp842mm.html

MiketheMechanic

https://www.boards.ie/discussion/comment/121624528#Comment_121624528

Excellent suggestion. I'll buy a sheet at TJ OMahoney and make up a lid to take the insulation.

Thanks

listermint

What's the point of this considering you've warm boarded the roof itself ?

How is the tank going to freeze. This seems unnecessary. My own attic isn't warm boarded it's a cold space. Merely has a Styrofoam lid same plastic tank. Never an issue whatsoever.

MiketheMechanic

https://www.boards.ie/discussion/comment/121626940#Comment_121626940

I would never expect that tank to freeze unless the conditions are apocalyptic!

It still gets pretty cold in this triangular crawl space though. My BER assessor pointed out that that because the tank supplies a shower with a flow rate of 14L/min (quite a lot of water) downstairs, then the "less cold" the cold water going down to the mixer in the shower is, the less hot water will be used - and consequently the less we have to run the gas boiler to heat the copper cylinder.

listermint

https://www.boards.ie/discussion/comment/121628677#Comment_121628677

Fair I suppose but I'd assume its nearly negligible difference considering the space is already boarded.