CH design and radiators...

[Tough Guy no. 1265]

:

te:

Won't the same happen to triples?

-- =

I have a photographic memory that was never developed.

[Tough Guy no. 1265]

Is that really necessary? How much heat can you lose through that?

[Johny B Good]

A hell of a lot. There's a much greater delta T involved.

[Tough Guy no. 1265]

But it's only during cooking. And a lot will be lost from the sides anyway. And the heat will go into your house so isn't wasted in winter.

[John Rumm]

More than likely. An old triple will probably still out perform and old double.

[Tough Guy no. 1265]

te:

rote:

Might aswell go one up on the Jones's and get a quadruple.

-- =

If "con" is the opposite of "pro", then what is the opposite of progress= ?

[Johny B Good]

That's exactly the same spurious reasoning behind the incandescent lamp is better brigade who try to defend their choice on the basis that the waste heat contributes to home heating, an argument that's only valid during the winter months and flawed by the fact that such electric heating is costing about 3 times the equivilent of the heat produced by a gas fired CH system.

In this case, I'm talking about an electric double oven were we'd rather not splurge 3 or more Kilowatts[1] of expensive energy on heating the kitchen in winter when we can avail ourselves of the much cheaper option, if needed, of lighting a burner (or four if we want a rapid warm up) on the gas hob.

As in the case of incandescent light bulbs, in summer, that waste heat is most definitely an unwanted 'side benefit'. Having disposed of that spurious argument, this just leaves the issue of safety involving the burn risk of touching an overly hot oven door.

I can only surmise that the old tricity fitted oven was likewise blessed[2] with triple glazed doors as the Bosch double oven replacement which neatly fitted in its place. I surmise that the use of triple glazing was demanded to avoid sidelining the efficacy of the more highly insulated top, bottom, back and sides. Despite this, I suspect the oven door may well have still represented the equivilent heat loss of the sum of the other five sides.

[1] Probably more like an average of between 1 and 2 KW once the oven has come up to a more typical 200/220 deg C temperature as opposed to going flat out at 270/280 deg C. [2] See through oven doors probably need triple glazing on safety grounds alone, never mind the tighter efficiency requirements of an electric oven to keep the overall energy cost comparable to a traditional domestic gas fired oven.

[Tough Guy no. 1265]

It's not 3kW. Even if your oven is that powerful, it's not on all the time., and a lot of that was necessary to warm the air inside the oven, and of course the food.

But the lights are used a lot more than the oven.

Oh don't be such a sissy! If you touch a hot surface, you remove your hand. Do you not have automatic reactions? I remember a teacher when I was at school telling me off for stirring a hot pan with a metal spoon, trying to convince me that the metal conducts heat and would burn me. I simply touched the side of the boiling pan, withdrew my finger, said ouch, and showed her my unburnt hand.

[John Rumm]

As with all insulation exercises you reach a point of diminishing returns where you never recoup the cost of the insulation...

Bit like doubling the depths of loft insulation - each doubling in cost results in an additional half of the previous saving. (approximately)

[Tough Guy no. 1265]

rote:

And a vast reduction in storage space, which is why I never had it done.= The stuff you store up there is insulation in itself anyway.

-- =

Only 55% of Americans know that the sun is a star.

[Tim Watts]

Hi Andrew,

Compact 6 - there's no info on the ultraheat website - but I do not see any bottom connections in the pictures on the vendor websites.

Is this the funky radiator where the bottom connections are underneath, centre bottom?

If so, do you know how you bring the pipes out sideways (so as to run

*up* on edge of the rad and onwards to the ceiling)?

Can you put the flow TRV straight into one of the top connectors?

Bit confused by the 6 series... Only for some reason the 6 TFs are easier/cheaper to get than the 4 TFs...

Thanks :)

Tim

[Andrew Gabriel]

The '6' means the radiator has 6 connection points (and Compact '4' means it has the usual 4 connection points). The two extra ones on the Compact 6 are underneath, both near the right hand end. However, the Compact 6 also has all the 4 standard connection points and comes with 2 extra blanking plugs.

You can use the standard top/bottom side connections, but in that case you might as well use a Compact 4. (IME, they sometimes supply a Compact 6 when you order a Compact 4, but that never matters.)

Yes. I suspect they work better at the bottom of the radiator where they are in the room-temperature air being drawn towards the rad, and less likely to receive any heat directly from the rad, although people do mount them at the top sometimes. If you have the pipework running up the wall from the side, I would probably mount the TRV horizontally at the bottom.

I think nearly all the TFs I ordered came as Compact 6's, although I only actually ordered 2 of them as Compact 6's. (Actually, I didn't even know about the Compact 6's until one of the Compact 4's came as a 6, and on the next order, I specifically ordered Compact 6's.)

Note that when using the underneath connections, it's important to connect the flow and return the right way around, as one of them is piped to the top between the panels, and the other is connected at the bottom. ISTR they came with a card pushed over the bottom connectors saying which was which, and the card was the wrong way around! The return must _always_ be from the bottom (flow doesn't matter).

[Tim Watts]

Right! I see... That's no problem then - I'll not mind which I get - thanks a lot for explaining that :)

Ah - that's also very useful... Thanks again!

The way it's working is our local plumber has been around again and he understands why I want certain things - and has suggested a day rate with an estimated number of days. This way, he's not messed up if I get picky about pipe routes (I will and I've told him there are certain routes I want to take to maintain access to other stuff). He's also suggested I order the rads direct but agrees with the general plan to get rads as oversized as possible.

So I think I might as well mount them as I get them - save some of the plumbers' time and I'll be sure they are mounted nice and strong (and I might do the 8 pipe holes in the wall so I can take time and make a clean job of them).

[Andrew Gabriel]

A couple more points...

Although the blanking plugs (including bleeding plug) are intended to seal on the O-ring, I have found these O-rings have a limited life. Unfortunately they have parallel threads as they aren't intended to seal on the thread (and they're short threads too), so I would suggest adding a thread sealing compound on their threads too. I've actually found this to be a much worse problem with other makes, but my 13 year old Ultraheats are starting to show some staining on some blanking plags now, so I intend to remove them all and reseal at next drain-down. Fortunately, it's just crystals from the inhibitor which wipe off, and not rust staining!

For 15mm copper pipes through masonary walls, 20mm electrical conduit makes a nice sleave to prevent any contact and provide a non-scratchy surface for any movement with pipe expansion (although it probably won't survive a nearby blowlamp).

[Tim Watts]

OK - I did remember you mentioning this a while back.

Do you have a particular sealant that works well? Perhaps a non setting or soft setting one like Virgin White so the plugs can still be removed?

Indeed - I have done this with all my potable water pipes. Re: blowlamp, I found I usually had a long enough straight run on one side to withdraw the sleeve for the soldering on the other side, then replace afterwards :)

I usually go through with an 8mm long pilot, then attack both sides with a TCT core bit which avoids blowing large lumps of plaster off.

[Andrew Gabriel]

I used PTFE tape as that was all I had to hand, but the thread is too short, so I ended up folding the tape length-wise. I have just assembled a towel rail in a situation where I can't use the normal taper-thread tails (take up too much space) and I'm having to generate a seal on a parallel thread with no sealing flange. I had some liquid PTFE from BES which I've used, and it's currently been left to see if it will set and seal, before the towel rail is connected up and pressurised. I suspect this is not the right stuff though. I will pressure test it with air for some time before it gets connected to the heating system - fortunately it will be a while before rest of the room is finished so I have time for experimentation.

[John Rumm]

I would have thought its an ideal use for LS-X

[Tim Watts]

Could be - does it mind heat?

I've used a drop of LS-X on drains here and there but I've never tried it on hot plumbing...

[John Rumm]

Not really - its silicone based and most silicone sealants are comparatively high temperature compounds.