Installing floor water supply distribution

systems with EDELFLEX

4.2.1 General

The drinking water supply is distributed from the risers to draw-off points on each floor. Floor manifolds downstream of the stopcock for a particular storey are an effective means of distribution and allow several different configura-tions.

Increasingly stringent hygiene, corrosion resistance, heat conservation and noise insulation requirements for pipework mean designers and contractors have to choose the right layout. Pipe runs are routed over the structural slab or within modular elements.

Conventional tee connections are replaced with runs using a single size of continuously flexible pipe, which is uninterrupted by intermediate connec-tions.

A suitable configuration ensures excellent distribution and allows the conditions necessary to reduce the growth of legionella to be achieved. Even with long runs, the small bore generally keeps the capacity of floor and spur pipes without circulation below the permitted limit of 3 litres.

The low capacity of the mapress EDELFLEX pressfitting system always ensures perfect hygiene, as the drinking water is changed rapidly after the stag-nation phases.

4.2.2 Pipe configurations

The size (outside diameter x wall thick-ness = 15 x 1.6mm) of an individual mapress EDELFLEX pipe allows a flow rate of up to 0.53 litres of water/sec with low loss floor stopcocks.

The flow velocity is then about 4.8m/s.

To arrive at the configuration, the fol-lowing factors have to be known or specified:

- Pipe runs

- Type of modular system

- Laid under plaster in conventional wall chases

- Location, type and number of draw-off points

- Form and frequency of draw-off The configuration taking account of the technical standards, regulations, codes of practice, etc, must:

- Fully exploit the pressure available for the pipe

- Keep the flow velocity high - Ensure water continually flows

throughout the entire pipe system - Ensure hygiene (rapid water change

after stagnation phase) by utilising a ring system to avoid stagnation if certain draw-off points are rarely used

To ensure a cost-effective floor system, it is advisable to adopt one of the fol-lowing pipe configurations:

- Spur - Series - Ring or

- Combination of the above

mapress EDELFLEX also allows cus-tomisation.

Less hygienic configurations, such as those using tees or even spur pipes, should only be chosen if the last draw-off point is used every day.

Series and ring configurations are the most cost-effective and hygienic. The higher flow velocities, with even pres-sure and heat distribution, and greater draw-off rates achieved, even with smaller bore pipework, give a ring cir-cuit advantages over all of the other options.

The designer can choose the most suit-able layout for the requirements from those shown and described on the fol-lowing pages.

4.2.3 Spur system

Figure 4.0-1 Spur configuration

Each draw-off point is connected to the floor manifold with a separate pipe. This arrangement is generally chosen if the pipes between manifold and draw-off points are short, the available pressure is low, and the draw-off points cannot be assembled in groups with a series or ring configuration.

Advantages + Small bore pipes + Low water capacities + Minimised pressure drops + Individual connection for higher

water demand + Lower design costs + Quick and easy installation

Disadvantages

– Longer stagnation phases

– Draw-off points have to be regularly used

– More space required for pipework and floor manifold

4.0 Applications and Characteristics

4.2.4 Series system

Figure 4.0-2 Series configuration

The pipe is continued directly from one draw-off point to the next, with twin connections. Draw-off points are grouped and several supplied by a com-mon pipe.

Advantages

+ Simple configuration

+ Short total length of pipe used + Quick installation

+ More compact floor manifold + Low volume of stagnant water + Stagnation avoided by water being

changed rapidly

+ Perfect hygiene if frequently used draw-off point at end of line

Disadvantage

– Increased pressure drop means high-est draw-off has to be at start of line if possible

4.2.5 Ring system

Figure 4.0-3 Ring configuration

As with a series configuration, twin con-nections are used to connect all draw-off points in turn to a loop of pipe, with a return from the last point to the floor manifold. Each draw-off point can be supplied with water from two sides. This allows high draw-off rates, with low pressure drops and smaller bore pipework. Ring systems also offer the best hygiene.

Advantages

+ Low pressure drops allow high off rates and significantly more draw-off points with same pipe bore + Pressure drops are about 30% less

than with series system and 50% less than systems using conventional tee connections

+ Various draw-off points can be con-nected further away from the floor manifolds and risers

+ More compact floor manifolds, since depending on the number of draw-off points they only need 2 connec-tions

+ Uniform pressure and heat distribu-tion

+ Optimum water changing

+ Short stagnation periods, since the water is changed even if only one draw-off point is used. This is there-fore also the most hygienic

configuration, even with rarely used draw-off points.

4.0 Applications and Characteristics

4.2.6 Combined ring system

Figure 4.0-4 Combined ring configuration

This is a configuration for higher water usage. A separate ring pipe can be used to connect each individual draw-off with a flow rate ≤0.4 litres/s.

Advantages

+ Effective water delivery where supply pressure low

+ Pressure drops about 30% less than with spur system

TWW

cold water

TWK

4.2.7 Combination system

Figure 4.0-5 Combination configuration

The spur, series and ring configurations can be combined.

Typical installation for a luxury apartment:

Individual pipe WC

Series pipe

Twin basin vanity unit Ring pipe

Kitchen with dishwasher and washing machine

Ring pipe

High-consumption shower and bath

Advantages

+ Customised pipe configuration + Small bore pipe even caters for high

usage at individual draw-off points + Low pressure drops together with

even pressure and heat distribution + Little stagnation

+ Most efficient changing of water at rarely used draw-off points