Penthouse flat, worst cold / hot water performance I’ve seen.

[Southsealee]

Hi everyone,

I’ve just assessed a top floor penthouse with what’s best described as Sod poor water pressure (1 bar standing, 0.25bar working) at 8/9 lmin... it has a conventional heat only boiler and cylinder in the utility, cold water storage and CH feed tank are about 3m higher in a stairwell to a roof terrace. There is about a 50m U shaped horizontal pipe run between the utility and storage tank / feed tank. There is an unmeasurably small amount of water flow at the float valves into these tanks at the best of times (float valves are new). Obviously caused by not enough pressure for the height of the building and a lot of restriction through the long 50m horizontal pipe run.

Another matter is that a previous engineer has been unable to refill the system following draining down to replace a zone valve, so the horizontal pipe run is more than likely air locked without an AAV in the ceiling void to vent. To top it all off all the walls and floors are beautifully tiled, some with engineered wood etc, lovely finish everywhere, ceilings included, no access hatches anywhere - you get the picture.

I’ve installed unvented cylinders a number of times and thats probably half the solution needed here, but it’s going to need a break tank and pump or combined accumulator and pump on the main... I’ve not had to find a solution to this kind of problem before, I was wondering if any other heating engineers have and what specification you would go with?

I also think the CH system needs to be switched to a sealed system, all the CH pipes are run in the ceiling and drop down, would be easier to clear air in a sealed system... or maybe a few AAVs in the ceiling void would be ok with the open vent boiler... what do other heating engineers think?

thanks, Lee.

 

[moonlight]

I would get my trainers on, run away

 

[Scott_D]

Could you fit an accumulator with pump At low level in the flat?

 

[oz-plumber]

Re: Heating System.
Pressurize it. I would never put AAV's in a ceiling space.
We do heaps of overhead heating systems and I haven't put any vents in these systems for years.
If a panel doesn't perform as well as it should, just turn off some panels and the air will eventually push itself into the radiator.
May only have to do that once a year, if that

 

[Southsealee]

I would get my trainers on, run away

Problem is - I quite like a challenge...

 

[moonlight]

Problem is - I quite like a challenge...

Thing is there are challenges and challenges. Good luck.

 

[Southsealee]

Could you fit an accumulator with pump At low level in the flat?

Yes Scott_d I have considered an accumulator but the ones I’ve seen need 1.5bar min static pressure, we only have 1bar here... I’ve had a quick look at Stuart Turner Mainsboost Flomate, combined accumulator and pump, but these have a limited run time from the vessel, then switches to pump which can only deliver the same flow rate as at the inlet, although at a higher pressure which gives the effect of a higher flow rate, as I understand it anyway. Maybe someone out there who has fitted one can elaborate on this? Having said that, the 80litre version can apparently deliver 16lmin flow for 12 mins (whilst pump is idle) which is equal to 192 litres... putting it that way it sounds pretty good.

If the ST Mainsboost Flomate supplied an unvented cylinder, charging the static pressure up to 3 bar, the expansion vessel on the cylinder would then adequately boost the hot water flow (as normal) when a hot tap is opened... would this then mean the SP Mainsboost Flomates vessel would retain its pressure for longer when a hot tap is opened? Therefore benefiting the balanced cold take off with more litres per min... so blended mixer outlets could give 16+ lmin?

Alternatively I’m thinking either a Stuart Turner Mainsboost iBoost or Grundfos Home Booster (both are breaktank + pump booster sets), feeding the unvented cylinder and balanced cold take off. Customer will have to sacrifice some space in the utility. Another problem is I would have to run a new drinking water cold to the kitchen before the break tank. All finished surfaces this property so not easy. I think the SP Mainsboost Flomate can feed drinking water as there is no need for a breaktank.

 

[ShaunCorbs]

Dab easy system would be my choice

 

[Southsealee]

Re: Heating System.
Pressurize it. I would never put AAV's in a ceiling space.
We do heaps of overhead heating systems and I haven't put any vents in these systems for years.
If a panel doesn't perform as well as it should, just turn off some panels and the air will eventually push itself into the radiator.
May only have to do that once a year, if that

The customers already had couple of engineers in who haven’t been able to clear the air... Ideal heat only boiler locks out on lack of water and you can hear there’s loads of air in the high level pipes. At the moment the system doesn’t work at all due to air locks. Maybe locking down all rads but one, in rotation until all air finds it way into the rads would work. I’ve only been to property to meet customer, just agreeing works / price at this stage.
[automerge]1590866811[/automerge]

Dab easy system would be my choice

Thanks Shaun, I‘ve heard of DAB... needs a separate break tank right? Why would you choose DAB?

What would you install if you wanted to avoid having to run an awkward cold main to the kitchen / drinking water? Do you know of a mains booster that can be used for drinking water, works on 1 bar static pressure and can increase flow to an unvented cylinder as well and all the cold taps?

 

[ShaunCorbs]

All one unit

DAB ESYBOX and ESYTANK - Booster Pump and Break Tank

The DAB ESYBOX and ESYTANK booster pump set comprises our best-selling ESYBOX booster pump and 480L ESYTANK cold water break tank

www.automatedenvironmentalsystems.co.uk

No mains boost will run an unvented I’m guessing the mains comes in under the sink unit ?