Installing rads and pipework

[imanc]

Hi,

This is my first post here.

I'm moving into a victorian house in a few weeks which has no central heating. And in part to keep costs manageable, but also just because I enjoy DIY, I'd like to see if I could install my own radiators and pipework, and get a GSR heating eng to take care of the boiler.

I've spent hours upon hours reading forum posts, watching Youtube videos, and reading the part L regs to try to determine the best set up and still have a few questions.

I'd be looking to install a 22mm/15mm twin pipe system with an upstairs and downstairs branches, but I'd like to hide the pipes, and there's a concrete floor downstairs.

Despite reading dozens of posts on the very subject and looking at the building regs, there appears to be no real consensus on how to do this.

Would it be best to keep pipework for both branches under the first level floor boards and supply the downstairs radiators from above? The "problem" I see is that due to door ways I'd need to have at least two drops, so I think a drain off value would be required on one radiator per drop. It also means two sets of 22mm piping (one for each branch) would be routed through the floorboards. To be honest, given this configuration, it seems a single branch/zone system would be easier.

Another option is to chase directly into the concreate and make a track perhaps 2-3 inches from the wall supplying each radiator. As there'll be an engineered wood floor over the top, this might be a cleaner idea.

Another option would be to horizontally chase into the wall at the skirting board. This would make it easy to service the pipes in the future, as I'd just have to remove the skirting. The only issue here is crossing doorways, so I'd have to do some chasing into the concrete floor.

Is one of these options more correct than the others? Or should it be tackled in a completely different way?

Cheers, imanc

[Roger Mills]

There's no easy answer when the ground floor is solid. If you want two zones, and if they're both going to be distributed between the floors, that's a lot of pipes to get in!

Have you considered having a single distribution circuit and then effectively making each radiator into an individual zone by means of a remotely controlled radiator valve?

Can you afford to raise the level of the ground floor by a few inches? If you can, you could install wet UFH downstairs - giving good comfort levels without using up any wall-space with radiators - and all the pipes would be under the floor.

[John Rumm]

By branches I take it you mean two separately controlled zones? (i.e. so you can heat one floor independently of the other)

Its the only realistic options...

In these cases its not uncommon to have a pipe drop per downstairs rad - with a pair of 15mm pipes dropping at each location.

Easier perhaps, but you need to weigh the cost of your typical usage pattern and if it would makes sense to be able to heat only one floor at a time.

Or underfloor heating downstairs, if you can afford to lose a couple of inches of room height by raising the floor level a bit.

Not as nice IMHO.

You could use microbore and manifolds for one or both sets.

[Roger Mills]

I suggested that too - but you'd need more than a couple of inches in order to get some insulation under the pipes. I did this when I converted a garage into a kitchen, which gave about 6 inches to play with, and even that was a struggle.

[harry]

Vertical runs of pipework are always a problem (ie how to hide them). They are put in unobtrusive places and you can buy plastic trunking to cover the pipes. Normal practice on a two storey building is to run the main pipes under the upperfloor floor with drops to below and (short) risers to the upperfloor radiators. It has to be said that radiator systems these days are obsolescent.

Your system will run far more efficiently as an underfloor system,ie pipes embedded in the concrete floor. This is because the water temperature is much lower, more heat is abstracted from the boiler.

Also there are no visible radiators.

The disadvantage is that the system takes longer to heat up and cool off. Also it's more mess and inconvenience.

This would however involve taking up/replacing the concrete floor as insulation is installed beneath. In a Victorian house this might be no bad thing, the floor may be very damp and energy losing. There are special systems for timber floors too.

[harry]

There is an alternative skirting heating system you might consider. These are fitted round the entire perimeter of the building and all the pipework is hidden. They are more effective than radiators but can be less efficient. However they entail much less mess and quicker to install, virtually all the pipework is hidden. There is one (of many) here.

[imanc]

Some great answers here, and it has cleared up which options are feasible given the solid floor. I'm liking the idea of a single zone with a remote controlled radiator valve. Can you recommend any remote controlled radiator systems? I want to look at pricing and what is involved in installing them. No doubt it is an electricians job.

I really like the idea of ground floor ufh. I'd need to take measurements and figure out if that much space could be sacrificed.

Lots of "ifs" as I haven't actually moved in and investigated, but I've also considered insulating the exterior walls and installing an electric ufh, with a good insulating underlay, which seems quite do-able for a DIYer.

I'd also looked at thermaskirt, but I've heard people have issues with clicking and clanking when it warms/cools, and the corner pieces are plasticky. So I've decided against it.

[Andrew Gabriel]

That's one hell of a generalisation. Certainly not true for many patterns of occupancy.

[Andrew Gabriel]

I looked at them when I put my central heating in. They couldn't deliver enough output in any reasonable sized room. Even in the hallway (highest ratio of skirting length to floor area), output would not have been enough. Might work in a very well insulated modern build, but not a Victorian house.

There was another product called (IIRC) Finway (doesn't seem to exist anymore), which was a much wider skirting with a finned pipe running through it which generated convection over the fins. That was nearer the mark, but 3" thick skirting wasn't acceptable.

My father used a much earlier version of this which is a Canon 8" high cast iron skirting radiator the whole 20' length of their living room (it came in sections you bolt together). It has a flat front face and a hidden finned rear with a water channel running through the casting. Even that generates less output than the whole room requires. Conventional radiators are extremely size efficient for their output, and when you move to other types of heat emitter, you tend to need something which is very much bigger to match the heat output.

[The Natural Philosopher]

Oddly enough I can see both sides of this.

The key is less occupancy and more the actual overall house design.

IF its insulated to the hilt AND has a reasonably large thermal mass - and that does make for a more comfortable and even heat and less overheating in summer - then the benefits of time cycling the boiler are much reduced.

OK it is accepted that a modern timber frame house with suspended floor has little or no thermal mass, even if it meets insulation standards.

I am less sure about harry's assertion that lower working fluid temperatures make for a more efficient boiler. That is a misunderstanding really. What counts is the temperature of the exhaust gases, not the working fluid. In a sense the exhaust represents a total loss from the house - any other boiler losses are internal to the building and contribute to its heating. apart from pipe losses in the ventilated attic etc.

Underfloor heating of wooden floors is far less slow to warm up as well, though it does place a few restrictions on the flooring type.

I think where I stand is this: The first step in designing and efficient house from a heating perspective is too get all the losses down by massive insulation.

The involves sealing it from draughts as well, which them implies a ventilation/condensation problem. That is conventionally solved by having explicit ventilation added, which then becomes the major heat loss in itself.

Heat recovery ventilation is not much used, but is the next step in that direction.

Once all this is done, heating requirements come down to less than the

100W per square meter that underfloor heating can reasonably provide.

At this point there is nothing special about UFH. Its simply a very large warm water radiator laid flat under the floor. There are even possibilities to use in-wall heating if for any reason the floor is unsuitable.

The thermal mass issue is somewhat separate. Undoubtedly a high thermal mass is infinitely nicer in very hot weather as it tends to follow the mean between day and night temperatures. Here we managed to stay below

25C when daytime outside temperatures were around 39C!!

25C is hot, but for most Brits, bearable. 39C is hard for most..

However in winter we pay the penalty - if those rooms with large amounts of masonry are kept warm it has do be done n a totally untimed basis and it chews fuel. Its very hard to leave the (mostly) unused dining room cold, and then expect it to be warm for visitors unless at least 24 hours advance warning is to be obtained!

So management and control systems are necessarily more complex with a big time lag.

BUT, this is a separate issue from UFH per se.

My Scandinavian based sister simply runs the heating 24x7 all year anyway. Its controlled to keep the massively insulated triple glazed home at a constant temperature, and if you had experienced a Scandinavian winter, you would understand why. No one wants to come home to an untreated house and shiver while it warms up. I remember when her daughter was amazed when I walked in without a coat or jacket 'but its winter, its cold outside ' 'yes, but I only have to walk 20 yards to the car, and that's warm'

In Sweden you do not leave the house in winter without insulated clothing. It might otherwise be the last thing you do. Neither do you run your heating on a timeswitch...

[The Natural Philosopher]

,

+1. victorian house with poor insulation may need 300-500W/sq meter.

Modern insulated house 50-100W.

sigh, I know. I looked at these things too.

IF you have a solid brick house consider dry lining with celotex in stud, and running UFH pipe over that and behind the plasterboard. If it an internal wall forget the celotex.

Coupled to a normal UFH temp reducing/separate pump system that can actually result in more internal space.

[John Rumm]

It also depends on how fussy you are... I don't find a pair of 15mm pipes dropping down the corner of a room that offensive in the grand scheme of things...

In the past I have also chased 15mm speedfit pipe into a wall for a similar drop for a location where the pipe drop would have stood out like a sore thumb.

[harry]

You could go the whole hog. Zero energy house. Depending on how determined you are.

[Dave Liquorice]

There's an important factor. Up the insulation on at least the outside walls. 50 mm of celotex type insulation as a minimum. Ideally have the pipe work on the warm side of the insulation if not lag it. The warmth in the void will help with damp control anyway.

Drops for each downstairs rad with a combination radiator valve / drain c*ck at one end.

UFH downstairs with good wall insulation is an alternative but would need the existing floor removing for a good 12" or so to get the insulation in, the pipe work, covering screed and final finish.

[ARW]

[Geoff Pearson]

I'm intrigued by a Victorian house with a concrete floor - must have been a (much) later addition - timber would have been the norm. I'd regard it with suspicion.

[Roger Mills]

I wonder whether it's really concrete. The OP hasn't bought it yet, and might have mistaken something else for concrete. It could, for example, be flagstones laid on soil - in which case removing them, excavating and creating a proper floor - with insulation - may not be too difficult.

[Tim Lamb]

In message , Geoff Pearson writes

I'm in a Victorian house. The kitchen floor is large red quarry tiles laid on ?? the middle room is suspended timber on sleeper walls and the end room is herringbone pitch pine woodblock on ??.

As you say, there has been ample time for *makeovers*. If suitable

*tuits* arrive I shall dig it all up in the spring and find out!

[imanc]

I actually get the keys next Tue (12th) and the first job is to rip up the old carpets, so I'll investigate. The estate agent did say that the solid floor was a later addition. It would be great if there was room for an underfloor UFH system.

[Dave Plowman (News)]

I do. No pipes or cables showing anywhere in this house - or any which are simply boxed in. Some rather longer runs than otherwise to achieve this, though. Luckily all my internal walls are stud types - and I have a cellar

- which does make it easier. I've even run the tails to the rads down behind the skirting boards.