MortarThePoint

Here's a comparison of ducting resistance per metre for different types. At 288m3/hr it works out as: 144m3/hr 288m3/hr 150mm Round 0.4Pa 1.9Pa 125mm Round 1.4Pa 3.9Pa 100mm Round 4.1Pa 14.3Pa 220x90 Rect 0.4Pa 2.0Pa 204x60 Rect 2.1Pa 7.8Pa 121x60 Rect 6.0Pa - 110x54 Rect 13.5Pa - http://www.nuaire.info/catalogue/Nuaire_Ducting_Specification_Guide.pdf

Here's what it would look like using Rectangular ducting on its side: Passing from one of the extractors: 150mm Round Straight 600mm 150mm Round Bend 150mm Round Straight 200mm 150mm Round Tee 150mm Round to 204x60 Rectangular Spigot 204x60 Rectangular Straight 1450mm 204x60 Rectangular to 125mm Round Adaptor 125mm Round Straight 450mm 125mm Round Bend 125mm Round Straight 350mm 125mm Round Vent/Grating I read bends count as 1.2m equivalent. This has 4 bends so overall is equivalent to 8m straight length of 204x60 I'd guess. I've read it should be kept under 5m equivalent, but is there a building reg that needs satisfying?

Thanks @Nickfromwales, I've seen those parts from other suppliers and I can't see an Inline Rectangule to Round Tee. I was think along the lines of a straight section of rectangular duct with a spigot in the bottom for a 150mm Round to join. I guess I join the two extractors in 150mm Round and then adapt to Rectangular instead. Any reason Rectangular can't be used on its side, so the 220 or 204 dimension is vertical?

This Thread has been stopped and restarted in the Ventilation section:

@Nickfromwales Posted: Any of this get you out of the 💩? https://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/Ducting_Flat_6/index.html

Our kitchen design has two side by side cooker hoods. Is there such a thing as an Inline Rectangular to Round 90 degree bend to put in the left hand hood as in the first image below or do I have to have them both bend/tee onto a straight run as in the second image. The blue circle is a soil pipe I have to get round and the dark brown lines are the wall surfaces of the kitchen. [NOTE: I accidentally started this thread in the wrong section so am stopping it there restarting it here]

Our kitchen design has two side by side cooker hoods. Is there such a thing as an Inline Rectangular to Round 90 degree bend to put in the left hand hood as in the first image below or do I have to have them both bend/tee onto a straight run as in the second image. The blue circle is a soil pipe I have to get round and the dark brown lines are the wall surfaces of the kitchen.

By that I assume you mean turning down the flow on loo cisterns etc so showers don't get starved. I like the idea of being able to isolate the family bathroom. A conventional plumbing setup wouldn't have remote balancing. I could use a pair of lever isolation valves for the family bathroom.

Yes, I expect 10mm would be fine for basin cold as well as hot. Also, should be OK to loo cisterns. I think a big flush these days is something like 6L and 10mm pipe can pass that over 10m at 1.5bar in 1 minute. How do you feel about what I should do in terms of wall and floor finish. What's the norm there? Bare blockwork feels a bit unfinished

A 25mm SDS bit would leave only 15mm of block between the holes. That's removing 63% of the material. Surely it's not a good idea to weaken a wall to that extent across 1.2m of width.

I presume you mean drill from the lower left which is the utility. It would be no drama for a few, but having a line of holes at 40mm centres isn't so appealing. I suppose I could stagger them vertically as well to make the hole c/c about 60mm. It's still across about 1.2m of wall if going fully 1:1 radial. Watched some videos of people core drilling at 45 degrees but that's with a pretty beefy jig.

Ignoring the Kitchen feeds, which may be able to be down low and so much more choice there, the 38mm core holes could be split as follows: That's a total of 4 core holes vs the 1:1 needing 10 (exc. kitchen). The compromises are: Master Cold manifold feeding bath, basin and loo cistern. May make sense to just use accessible Tees. Items not individually isolatable. Guest Cold manifold feeding shower, basin and loo cistern. May make sense to just use accessible Tees. Items not individually isolatable. Family Cold manifold feeding shower, bath, basin, and loo cistern. Would be kept accessible but items not individually isolatable. Family Hot manifold feeding shower and bath. That's effectively a Tee. Would be kept accessible but items not individually isolatable. One of the holes has 3no. 15mm Hep2O pipes in. That is a squeeze and may require some different conduit (3no. 15mm circles fit in one 32.5mm circle and the solvent weld pipe I am using as conduit is 32mm ID). Attic is a future renovation opportunity to add a loo. There are two compromises here (a) it is 10mm hot and cold (b) it's hot is shared with three colds so not ideal but feels minor. Those feel like minor compromises for the significant benefits of reduced core holes and pipe grief. The coarsest level of isolation is at the room level (Family H & C, Master C, Guest C). In terms of in use, I think the only compromise is: It does have the Guest loo cistern feed from the same main 15mm pipe as the Guest shower (cold). Probably worth stepping the loo cistern down to 10mm to hopefully keep the shower as the preferred path, though I could adjust the cistern inflow if required. Basin is also fed off this, though that is less binary than the loo filling. I don't expect the bath and shower in the same room to be run at the same time.

The S-bends can be eased but using the dimension in and out of the diagram to help a little.

That's fair, it could have been thought out better. I am going through first fix and catching up some of those now. I wasn't aware of the manifold approach at design time and presumed I'd just have two pipes coming through, plus heating & wires. I know a normal builder wouldn't be worry about this in the slightest and would have the whole house off two pipes with Tees and Elbows a plenty. But that's not how we all roll around here which is good. The kitchen ceiling on the right of the diagram has Hollow Core Flooring (HCF, precast concrete) which is easy enough to drill through vertically, but not practical to route into the surface. Some suppliers provide that at design stage, but not mine. I'll have a suspended plasterboard ceiling (on the Gyplyner system) giving a service void of around 55 - 75mm (HCF is designed slightly bowed and may vary a bit by room). The Utility, left of diagram, is single storey and so the plasterboard ceiling will be screwed to the roof trusses. The layout of the house is such that the Master bathroom and Guest bathroom are immediately above that Kitchen/Utility wall. In other words, higher up that Kitchen/Utility wall turns into the exterior wall of those bathrooms. The cylinder is well placed close to all outlets except the Family bathroom which is at the other end of the house. The fly in the ointment is getting through the blockwork cavity wall. Actually, only the Family bathroom is served via the full S-bend. To most other outlets the pipes will need to head straight up. Part of this whole game is rolling with the compromises and trying to make them as risk free as practically possible. I only really have three four options at this stage: Utility Manifolds : totalling around 30 ports and running that many pipes (plus heating and wires) through about 12 core holes. Occupying the top corner of the room (above or inside kitchen wall cupboards) with some of the pipes' s-bends. Kitchen Manifolds : minimal pipes (2 core holes) through wall then 30 ports and and pipes. Manifold housed in the top corner of the room (above or inside kitchen wall cupboards). Satellite Manifolds : Smaller Utility manifolds, fewer wall holes, local accessible manifolds. Still a small amount of space taken up above/inside kitchen wall cupboards. Go through the wall higher up : It's occurred to me I could go through the walls to the Master and Guest bathrooms in the roof space. I would have to insulate around all the pipes and ensure they get warmth from below, but it's an option. Having once upon a time walked into my in-lasws' house with a burst loft tank raining inside, I am keen to avoid any pipes going anywhere near unheated spaces. I was the one who discovered the flood. Strange walking inside from the rain outside and into the rain inside before turning the light on.

@Nickfromwales and @TerryE This is the awkwardness of the pipe routing through the Kitchen/Utility wall. The diagram is to scale. I don't think I could core drill at an angle which would otherwise help greatly. It already looks like I'll need to box in above the kitchen cabinets for this reason.

Below is a comparison between satellite manifolds and a 1:1 radial arrangement. Greyed out doesn't have to pass through the wall. In the 1:1 Radial arrangement, 29 pipes (17no. cold 15mm, 2no. cold 10mm, 6no. hot 15mm, and 4no. hot 10mm) have to pass awkwardly through the Kitchen/Utility wall. In the Satellite Manifold arrangement that comes down to 11 (5no. cold 15mm, 4no. hot 15mm, and 2no. hot 10mm). The Satellite Manifolds would have to be accessible, but wouldn't necessarily feature shutoffs. 1:1 Radials: Satellite Manifolds:

Servicing loos and basin colds with 10mm would halve the number of core holes I drill for cold if using 38mm core drill. Such a hole allows 32mm pipe as conduit and 2x 15mm and 2x 10mm within (or 6x if only 10mm pipes). Otherwise I need 11x 38mm core holes for all pipes. I've wondered about 78mm core with downpipe conduit. Unfortunately, a letter box isn't practical. Would be better.

It's quite tough 10N aggregate block so harder work, but not the main concern. I don't think flows would suffer as I don't expect the bath and shower in a room to be running at the same time. Satellite manifolds would only service one room. All pipes passing through will then need to bend down to go to the manifolds, so that will be a bit tricky. Added to that is the plant room ceiling is 150mm lower than the kitchen ceiling void where all the pipes come from. I need to box an area out for all this above kitchen cabinets and have even wondered if I should put the main manifolds there. All that said, I appreciate your experience and an trying to see if I can do 1-1.

Doesn't sound like there is any point in getting a twin coil cylinder then in my case. Any future oil based changes would be grievous anyway and probably not be impossible with only a single coil. Spacing heating is the lion's share of heat demand anyway and doesn't affect the cylinder.

Interesting, I didn't know such a thing existed. I think there is only one model that is pretty large and incorporates a 17kW ASHP (15-26kW oil). This hybrid is about £3k more than the straight ASHP 17kW unit.

I thought check valves and non-return valves where the same thing

I assumed it was for drawing convivence. Cylinder drawing and coil placement is just a rough sketch so don't worry about placement or indeed if I have the FLOW and RETURN connected the right way round 🙂

I'm trying to see if I should hedge my bets. I have been currently quoted a single coil cylinder (3.0m2) but there is a twin coil (2.2m2 + 1.0m2) option I could ask for which adds about £60. I'd rather not ask for it as I have been quoted without and I don't want to upset things, but I don't want to miss a trick. I don't think I would be going solar thermal and PV could just use the ASHP or immersion heater I guess. I could possibly imagine two future changes: Adding an oil boiler as a dual source option Adding a wood burner with back boiler

OR gate but importantly not an XOR gate 😀 That said, if they were pressure driven pumps, rather than positive displacement driven, then one pump would bully the other closing that one's non-return valve and mean you only have the stronger pump circulating. You'd want positive displacement pumps. I think you could solve it with pressure driven pumps by using pressure regulators after the non-return valves, but you'd not start there.

Perhaps a daft question. @Nickfromwales or @TerryE you probably know the answer. I understand that one way of connecting two heat sources to one cylinder is to have two coils in the cylinder itself, but can't you achieve the same thing using two non-return valves and a single coil? Example diagram below. Reasons that come to mind for two coils: Is it because the two heat sources may need different Return temperatures to be operating most efficiently? That assumes the Return temperature is not at the temperature of the water in the cylinder, which would be the case with maximum heat transfer. Also that would only be a problem if using both heat sources at the same time. Is it more to do with one heat source being used to heat one part of the cylinder and the the other another part of the cylinder?