Boiler hot tank pipe runs

[Nickfromwales]

Solar thermal water heating would be a waste of money IMO. Just a one trick pony, very inefficient for high temp recovery and a pita to look after. Spend every penny of that money on a small PV array, and add to it as time goes on ( if the budget doesn't allow for a full array now of course ). 

If you've got oil and Ufh, then the two aren't matched very well for starters, as the boiler is either going flat out or off and Ufh cannot consume the heat as quickly as the boiler produces it. The way to deal with that is to either use a small buffer tank on the feed to the Ufh, with the boiler pulsing high grade heat into that where it is temporarily stored, and then allow the Ufh to trickle feed off that, or you fit a TS. The TS will provide a means of regulating the heat from the boiler to the Ufh very well, as would the buffer option, with the difference being that the TS will also provide instant constant dhw. A TS will give very high flow rates and would be a better option for later down the line when you find that dhw demand goes up. An UVC will always be restricted in output by its size, but not so with a TS when served ( on demand ) by a high temp heat source ( such as an oil boiler ). Size wise, you'd probably need a 400ltr TS to manage with this size of property ( number of bathrooms vs occupants ) to ensure peak dhw production. The heating requirement is really neither here nor there btw. 

I'd look at putting the TS in store 1, and the Ufh manifolds etc in store 2. Expansion vessels can go in the attic out of the way, and that'll be around 70-80 litres for a system like this so quite significant. A pair of 35ltr vessels is easier to manage than one 70ltr, and the oil system boiler will have between 18 and 24 ltrs expansion internally so will take you to the required volume with a bit of headroom. Exact calcs for this sizing can ( and must ) be done later when you settle on a design. 

Have the manifolds for hot and cold water as close to the TS as possible like this. 

That's a 500ltr TS and a 300 ltr cold mains accumulator.

[Ferdinand]

On 27/05/2016 at 13:21, vfrdave said:

Are there any guidelines on where boilers should be situated in terms of longest run to radiator or UFH manifold.  Likewise the same for a DHW tank and its proximity to bathrooms/en-suites etc as well as to its heating source.  My bungalow is a non-traditional design and can only be described as a Z stretched left to right with one block being living and the other being sleeping.

This is probably aimed at Nick but welcome to others to contribute as always.

Floor attached hopefully helps

Have to say I like the design - it is almost a bent variation of the old countryhouse sleeping wing / public wing / stable block thinking, and even has a bit of a monastic feel.

Ferdinand

[ProDave]

On 29 May 2016 at 17:44, Nickfromwales said:

Plenty of room to go in the attic if you'd rather keep the cupboards for clothes / storage etc.  That's the last horizontal UVC, but there's no HZ TS's   

How on earth did you get that in there? the only way I can see is slot it in when only half the roof trusses were on?

[Stones]

If you look closely, there appears to be a cut in the truss below the nail plate.  I'm guessing the length of 6 X 2 was bolted on to compensate.  Nick?

[Nickfromwales]

3 graded 4x2's on flat holding the stainless cradles. 

And yes, the upright was cut out entirely ( couple of inches short of the plates iirc ) and then the original piece fitted back in to fill the gap back up ( to stave off compression force) and a bigger timber screwed in to sister and reinforce. 

The idea is that the entire cylinder can be removed with a pair of adjustable spanners and a cordless drill in less than 30 mins. 

Work of art that one. The customer said it reminded him of a ship's boiler room . I did that so it didn't impede on the storage space in the attic, which I created by removing the original timber raft and multiple cold water storage tanks etc. I fitted 3 X 6' fluos and boarded the whole thing in weyroc plus cut out and oversized the original attic hatch to fit a Fakro ladder. Great pieces of kit. 

NOTE :

Fyi if you put a boiler or cylinder up an attic and you ever require a manufacturer visit for inspection / repair / replacement etc then you MUST have a FIXED ladder, continuous and sufficient boarding of the floors to gain safe access and it must be lit. Anything less and they'll walk out the door. They WILL NOT go up a free standing step ladder. 

[ProDave]

In light of the other thread about drilling roof trusses, did you get a structural engineer or the joist manufacturer to approve you cutting out a section and replacing it?

How much PL insurance do you have?

[Nickfromwales]

I can tell you that I left that stronger than when I got there. I cut below the top plate and above the lower one in order to get the cylinder in. One timber got cut only. The new support timber was sistered over the original piece which I reinstated, and the additional support timber was thicker and wider that the truss section that I cut out btw. It was fixed above the top plate ( into the roof rafter ) and below the bottom plate ( into the ceiling joists ) so I'll sleep as soundly tonight as I did last night. 

PL a-plenty  but not needed it in over a decade ( when I took the policy out first ). 

I have a strict rule, don't touch it unless you can make it the same, or better. I strive for the latter in everything I do.

[ProDave]

I'm not questioning your ability, or doubting that what you left is stronger than the original. But the point is neither you or I are actually qualified to make that assesment. That is structural engineer teritory.

I'm just saying this in light of the holes in the truss thread. IF it turns out someone says the trusses have to be replaced, then someone is going to need a very good PL insurance policy to pay for it, or they will end up bankrupt.

[Nickfromwales]

Thanks Dave.   that wasn't meant the wrong way and I know what you're saying. 

Off the record, about the truss thread, I would bet my left nad that there would never be any issue, ever, with those trusses. They're going to have been over engineered anyway and even though the manufacturers will want to cover their arses, I'd be beyond shocked if there was even a hint of a failure tbh. I've seen joists like that with 2"x4" cut outs and worse, yet they've been there for years without issue, and are still there as I type this. This is based on me seeing literally hundreds of these scenarios, not just from me making an assumption. 

Rules are there to be followed, of course,  and any trade will be ( or should be ) aware of joist rules in their most basic form, so these guys should have checked first and drilled after. They've gone in the wrong way, and may have to face the consequences. The difference between them and me is I stop, assess, and engineer a solution rather than just crack on. If I think it needs the Feds involving, then in they come. 

What does shock me is the number of customers who will stop going ahead with a knock through etc when I say an SE will cost around £350 and the BCO sign off will be around the same ( when my price for a wall-down steel-in is around £1500 before professional fees ), and then when they find out they have to pay half that again for the sign off they say no thanks. I know then they'll go to someone who will just do the job regardless and they'll smile just the same for the job with no recourse. 

As with everything, there is wheat and there is chaff. 

[ProDave]

A serious question re drilling joists.  That roof truss has an intermediate support. Do you treat the joist as a whole when working out the safe areas to drill, or do you treat the now two halves of the joist individually when working out the drilling zones?  that sort of information never appears anywhere in any guidance notes.

It is quite likely the house has the same joist throughout and some may have an intermediate support wall and others may span the whole gap in one go.

I am watching that truss thread with interest. The outome could worry a lot of electricians.

[Nickfromwales]

From what my small brain can ascertain, those plates are as strong, if not stronger, than the actual points elsewhere in timber. I consider those to be continuous uninterrupted members. If they weren't then the joints would have to be manufactured to land on pad stones or steels / supporting walls wouldn't they ?

[ProDave]

No I don't mean the nail plates.

Say you have a joist that spans the whole width of the house and is sized to do so. It's easy to work out the 0.25 - 0.4 span drilling zones.

Then you stick an intermediate support wall under the joist at say 1/3 along its length.  Do the drilling zones remain the same, or do you now treat it as two seperate joists each with their own drilling zones?

[PeterW]

On 29 May 2016 at 17:44, Nickfromwales said:

Plenty of room to go in the attic if you'd rather keep the cupboards for clothes / storage etc.

That's the last horizontal UVC, but there's no HZ TS's   

Newark do a horizontal TS... Was about £1100 IIRC when I enquired. 

 

[PeterW]

3 hours ago, ProDave said:

No I don't mean the nail plates.

Say you have a joist that spans the whole width of the house and is sized to do so. It's easy to work out the 0.25 - 0.4 span drilling zones.

Then you stick an intermediate support wall under the joist at say 1/3 along its length.  Do the drilling zones remain the same, or do you now treat it as two seperate joists each with their own drilling zones?

Depends on how it's been designed..!

trusstech send a design doc with their deliveries that shows the support points - looking at that other thread you would need to know what the span was and if that wall was classed as a support wall. 

Just from looking I would say that those trusses have been designed as full span and there may be a point in the build where they are a full open span. It's quicker and cheaper for the designers to do 35 of one design, rather than do 3 or 4 different ones as the danger with that is that either the roof ends up out of alignment or the wrong truss goes in the wrong place !

I was quoted £4 per truss more for a bottom chord at 190mm than 100mm - on a 7m span you can't even buy the timber to do that yourself so it was a no brainer. 

[Nickfromwales]

4 hours ago, PeterW said:

Newark do a horizontal TS... Was about £1100 IIRC when I enquired. 

 

Apparently not the best for stratification. Iirc it was posted about on EB briefly. 

[vfrdave]

On 5/30/2016 at 08:36, Nickfromwales said:

Solar thermal water heating would be a waste of money IMO. Just a one trick pony, very inefficient for high temp recovery and a pita to look after. Spend every penny of that money on a small PV array, and add to it as time goes on ( if the budget doesn't allow for a full array now of course ). 

If you've got oil and Ufh, then the two aren't matched very well for starters, as the boiler is either going flat out or off and Ufh cannot consume the heat as quickly as the boiler produces it. The way to deal with that is to either use a small buffer tank on the feed to the Ufh, with the boiler pulsing high grade heat into that where it is temporarily stored, and then allow the Ufh to trickle feed off that, or you fit a TS. The TS will provide a means of regulating the heat from the boiler to the Ufh very well, as would the buffer option, with the difference being that the TS will also provide instant constant dhw. A TS will give very high flow rates and would be a better option for later down the line when you find that dhw demand goes up. An UVC will always be restricted in output by its size, but not so with a TS when served ( on demand ) by a high temp heat source ( such as an oil boiler ). Size wise, you'd probably need a 400ltr TS to manage with this size of property ( number of bathrooms vs occupants ) to ensure peak dhw production. The heating requirement is really neither here nor there btw. 

I'd look at putting the TS in store 1, and the Ufh manifolds etc in store 2. Expansion vessels can go in the attic out of the way, and that'll be around 70-80 litres for a system like this so quite significant. A pair of 35ltr vessels is easier to manage than one 70ltr, and the oil system boiler will have between 18 and 24 ltrs expansion internally so will take you to the required volume with a bit of headroom. Exact calcs for this sizing can ( and must ) be done later when you settle on a design. 

Have the manifolds for hot and cold water as close to the TS as possible like this. 

That's a 500ltr TS and a 300 ltr cold mains accumulator.

Thanks for all of this valuable information @Nickfromwales just realising I never passed on my gratitude for your knowledge.

[Nickfromwales]

Swings and roundabouts here Dave .  Thanks anyhoo.