Tricky internal condensate pipe routing - 25m?

[warehouse_fun]

Hello,

I'm looking for advice/opinions on installing tricky internal condensate pipe routing for a new boiler to replace an old non-condensing unit. Been losing sleep over this...

The property is an old warehouse converted flat, making things fun. External routing isn't possible for a range of reasons (incl. modification of building exterior and technical infeasibility).

The best internal route I've come up so far (with the help of 3 heating engineers, 1 of whom is crazy enough to give it a stab) would need to be pumped vertically up approx. 3m (to high ceiling) from the boiler then along a ceiling architrave through main living area approx. 10m horizontal, turn a right angle (L-shape room) then run for another 5m along more ceiling architrave horizontal, then around/through a plastered 80cm wide brick support pillar (most of the fun) into a void above the kitchen, then vertical down 3 metres into the kitchen sink area/main gravity waste pipe.

Most of this pipework I can conceal in the architrave/void but I believe some around the pillar (if possible to traverse) is likely to be visible which is displeaing to me but seems the least-worst option.

The total run needed would be approx. 25m. I'm curious about:

1. Whether having long horizontal sections (in architrave) that I cannot slope for aesthetic reasons will cause drainage problems. I know external runs need sloping to avoid freezing but not sure if internal is the same. Due to the sheer length here, quite a lot of fluid would be retained inside the pipe.
2. Anecdotally the likelihood of this pipe having leaks/drainage problems i.e. water into my living area.
3. Noise of condensate fluid flow/pump, again due to runnnig through living area.

Under wooden floor is another option. This would be more direct (approx. 13-14m horizontal also) but involves destruction of 800 sq/ft of solid oak flooring in otherwise good condition i.e. costly to replace and even more so should it leak into my downstairs neighbour's flat ceiling.

Relocating the boiler to the kitchen has a similar problem of wood floor destruction for the gas/ch pipes and also requires cutting the exterior brickwork for a new flue (again a no-no). So ruled out.

Any opinions/experience gratefully received!

 

[ScottishGasMan]

As its pumped you can get away with horizontal runs where you couldnt/shouldn't with a gravity fed system.

The pipe from most condensate pumps is quite narrow and typically you wouldn't hear the water flowing through it, but after the pump stops depending on where abouts it transitions back to drain pipe from the condensate flex you may get noise from water/air movement

The engineer would need to check with the pump manufacturer on maximum length the pump could deal with also, it will state clearly the height it can pump to, but then to overcome the resistance of a long length of narrow pipework may cause premature/repeated failures of the pump so one thing worth checking out first

 

[just pumps]

https://www.saniflo.com/us/installing-a-boiler-or-air-conditioner/82-sanicondens-best.html
Claims ^15ft and > 150ft, needs a fall on the horizontal though and replacement of the discharge hose that comes with it to ensure no joints to leak.

 

[warehouse_fun]

Thank you both gentlemen, much appreciated. Sounds feasible.