Distribution hot domestic water

Multiple distribution systems for domestic hot water (EPG calculation) may be specified within the project. For example, consider a simple system including an electric water heater in the kitchen with a short pipe to the tap, or a circulation system with multiple hot water storage tanks. Only data regarding the possibly present (collective) circulation systems needs to be specified here because the distribution efficiency is partially combined with the emission efficiency for domestic hot water.

In the hot water distribution system, a generation configuration must be selected to provide the heat for the system. Only generation configurations with specified hot water generators will appear in the list; configurations without these will not be included.

Circulation System

Circulation system is present

This box indicates whether a circulation system is present in the building or part of the building. A circulation system can be specified only if the generation configuration is a collective system, which should be specified in the generation configuration for domestic hot water. The losses of the circulation system will be captured in the distribution efficiency, whereas the other energy losses are included in the emission efficiency, e.g. the losses in the pipes to the taps.

Circulation system in permanent operation

This box indicates whether the circulation system in the building or part of the building is permanently in operation. If this is not the case, additional heat losses due to cooling are charged which are included in the distribution efficiency. By unchecking this box, an additional input field appears in which the percentage of time for which the circulation system is in operation can be indicated. Whether or not the circulation system is in permanent operation does not affect the calculations in case the flat rate method is applied to compute the distribution efficiency, see Pipe data.

Publications

 

Percentage van tijd in bedrijf

The percentage of the day for which the circulation system is in operation can be indicated here if this system is not in permanent operation. This value does not affect the calculation results in case the flat rate method is applied to compute the distribution efficiency, see Pipe data.

Power circulators known

If the power of the circulators is known this should be specified here by checking the box; an additional input field then appears in which the power of the circulator can be expressed in W. Currently, it is required to specify the power of the pumps as the alternate method is not supported yet.

Publications

 

Pipe data

Calculation method

The contribution of the pipes to the distribution efficiency may be computed with the flat rate or detailed method, which can be specified here. When choosing the flat rate method, only the insulation size for the system is required. If the detailed method is applied the pipes, materials, and insulation size for the system need to be specified.

• Flat rate
• Detailed

Publications

 

Pipe insulation

The pipe insulation needs to be specified if the calculation method for computing the distribution efficiency is flat rate. The pipe insulation determines the distribution efficiency as indicated in NEN 7120, Section 19.4.3.3.

• Uninsulated
• Minimum thickness of 10 mm
• Minimum thickness of 20 mm

Publications

 

Detailed calculation method

If the calculation method is chosen to be detailed, the above screen appears in which the piping of the circulation system can be specified. Pipes may be added, copied, and deleted using the icons in the screen.

Sufficient data on the insulation of the circulation pipes known

With this box it can be indicated whether the data on the insulation of the circulation pipes is known, or whether it should be estimated, see Insulation thickness.

Number

This number represents the number of identical pipes in the system. The length of the pipes is multiplied with this number and used as such in the calculations.

Length

This represents the length of the pipe section, expressed in m.

External diameter

The external diameter of the pipes should be specified as indicated in NEN 7120, Tables 19.4 and 19.6. The U-value per meter of copper pipe is determined using this external diameter in combination with the insulation thickness.

• 10 mm
• 12 mm
• 15 mm
• 22 mm
• 28 mm
• 35 mm
• 42 mm
• 54 mm
• 67 mm
• 80 mm

Publications

 

Material

The pipe material is specified here.

• Copper
• PE Polyethylene
• PEX PE with cross-links in the polymer structure
• PEX-Al PEX with an intermediate layer of aluminium
• PVC-C
• PPR Polypropylene
• PB Polybutylene

Publications

 

Insulation Thickness (insufficient known data)

When insufficient insulation data is available, the insulation thickness is specified according to NEN 7120, Table 19.6.

• Uninsulated
• Minimum thickness of 10 mm
• Minimum thickness of 20 mm

Publications

 

Insulation Thickness (sufficient known data)

When sufficient insulation data is available, the insulation thickness is specified according to NEN 7120, Table 19.4.

• Uninsulated
• 10 mm
• 15 mm
• 20 mm
• 25 mm

---

Back to Resources