Plumbing advice needed

sparklepig

Hi,

I'm in the middle of a new build and I've purchased a defro solid fuel burner with 1000 litre buffer tank. I'm installing UFH on both floors of house and locating the burner in a shed about 30 meters away.

Can I run 1 hot water pipe from burner (shed) in to house and then use a manifold to run it to the 2 separate UFH manifolds and also to another manifold to supply sinks/baths?

Any help/advice would be really appreciated.

sky6

The distance is too great. You need to reconsider the location of the Boiler. The Boiler should feed the Thermal store and then the store feeds the Manifold. what's the other source of heat for the thermal store.

sparklepig

Unfortunately relocation is not an option. No other source for heating.

I didn't think distance would be an issue as the hot water will be pumped in from the 1000ltr hot water tank in the shed?

K.Flyer

sparklepig wrote: »

Unfortunately relocation is not an option. No other source for heating.

I didn't think distance would be an issue as the hot water will be pumped in from the 1000ltr hot water tank in the shed?

In winter without the best of insulation there could be a fair amount of heat loss on a 30 metre run. Are you running a single hot water pipe or a circulation pump on two pipes.

sky6

I would say the heat loss over that distance would be 30 to 50 %. The very least I would do as said by K Flyer is run a continuously circulating two pipe system. This would mean having at least a constant temp in the pipe work feeding the manifolds.
You could also use one of the special insulated pipe on the market like Calpex or similar. There supposed to lose only 1% over a given distance. But it's not cheap at 50 E a Metre.
Either way unless you have a free source of fuel I think you will find it too expensive and unsatisfactory in the end.

sparklepig

The pipes will be well insulated so no worries about heat loss. As its recommended to run UFH 24/7 during winter the pipe will have a constant warm feed through it.

My thinking was to have defro boiler in shed with 1000 litre cylinder beside it. Pump hot water from cylinder to 3 port manifold in utility room in house.

port 1: UFH upstair
port 2: UFH downstairs
port 3: to seperate manifold feeding hot water outlets

Would this be possible?

tmcdlk

Are you planning to have a 1000L buffer or a 1000L domestic hot water cylinder in the shed? Sounds like the two are being confused. OP maybe add a bit more detail of the proposed system.

Solid fuel boiler heating a 1000L buffer located in the shed,
insulated underground F&R pipework from the buffer to the underfloor manifolds
domestic hot water? Separate cylinder located in the house?

Do you plan to add any other heat sources such as a stove?

Calahonda52

sparklepig wrote: »

The pipes will be well insulated so no worries about heat loss. As its recommended to run UFH 24/7 during winter the pipe will have a constant warm feed through it.

My thinking was to have defro boiler in shed with 1000 litre cylinder beside it. Pump hot water from cylinder to 3 port manifold in utility room in house.

port 1: UFH upstair
port 2: UFH downstairs
port 3: to seperate manifold feeding hot water outlets

Would this be possible?

This is pretty crazy horse territory really.

The UFH will take the hot water at perhaps 42 C

So is the underground flow pipework from the tank going to be at 42 C ( the lower the better for reduced heat losses, (the earthworms won't want it too warm)?


If so how will you get hot water at 60 C?

The heat losses on 30m or 60m or possibly 90 m of pipework will be high.
Well insulated pipe will still lose a lot of heat.

sparklepig

No other heat source and no cylinder to be located in the house.

1000 litre buffer tank in shed. Sending hot water to house at about 70C with the expectation to lose between 5-10C over 30 meters. Won't the mixing valve on the UFH bring it down to 42? Leaving 60-65 for domestic hot water.

Calahonda52

sparklepig wrote: »

No other heat source and no cylinder to be located in the house.

1000 litre buffer tank in shed. Sending hot water to house at about 70C with the expectation to lose between 5-10C over 30 meters. Won't the mixing valve on the UFH bring it down to 42? Leaving 60-65 for domestic hot water.

I have no idea, but just wondering about the flows:
say 100 litres of 70 degree water arrives at the 3 port manifold, so u have to dilute it down with cold water to bring it to 42 degrees, lets say 15 litres, (too early for math)
so you now have 115 litres...
As I say I don't know so am interested so see how this actually works.
Maybe u need a heat exchanger and the UFH is a sealed loop.
The domestic hot water will require a heat exchanger as well or is the plan to have one in the buffer tank.

ps: whats the plan for hot water in the summer?