Calculating The Applicable Draw-Off Demand Per Draw-Off Point To Be Considered; Calculating The Demand Factor N - Viessmann Vitocell 100-H Technical Manual

Sizing
(cont.)
Table 3 – Accommodation with deluxe equipment level
Existing amenities per residential unit
Room Equipment
Bathroom *4
Bath
Shower cubicle
Washbasin
Bidet
Kitchen 1 kitchen sink
Guest Bath
room
or
Shower cubicle
Washbasin
Bidet

Calculating the applicable draw-off demand per draw-off point to be considered

The respective draw-off demand w
the calculation of the demand factor N can be taken from table 4.
Table 4 – Draw-off demand w
No. Sanitary equipment or draw-off point
1 Bath
2 Bath
3 Small bath and sit bath
4
4 Large bath (1800 mm × 750 mm)
5 *7
Shower cubicle
head
6 *7
Shower cubicle
*9
head
7 *7
Shower cubicle
*10
head
8 Washbasin
9 Bidet
10 Washbasin
11 Kitchen sink
For baths with considerably varying available capacities, apply the
draw-off demand w in accordance with formula w
v
and use it in the calculation (ΔT = 35 K).

Calculating the demand factor N

In order to establish the heat demand for DHW to all residential units,
it is first necessary to convert the data into the heat demand for DHW
of the standard residential unit.
The following characteristics of the standard residential unit are
agreed:
1. Room factor r = 4 rooms
2. Occupancy factor p = 3.5 people
3. Draw-off demand w
v
The heat demand for DHW of the standard residential unit with 3.5
occupants × 5820 Wh = 20370 Wh corresponds to the demand factor
N = 1
*4 Size different from standard equipment level.
*5 If no bath is installed, a bath is assumed instead of a shower cubicle as with the standard specification (see table 4, no. 1) unless the draw-
off demand of the shower cubicle exceeds that of the bath (e.g. deluxe shower).
If several different shower cubicles are installed, at least one bath is assumed for the shower cubicle with the highest draw-off demand.
*6 If no bath or shower cubicle is assigned to the guest room.
*7 To be included in calculations only if the bath and shower cubicle are in separate rooms, i.e. if simultaneous use is possible.
*8 Corresponding to 6 minutes in use.
*9 Fitting flow rate class A to EN 200.
Fitting flow rate class C to EN 200.
*10
VIESMANN
14
*4
*4
for the draw-off points included in
v
v
with mixer tap and economy shower
with mixer tap and standard shower
with mixer tap and deluxe shower
= c × V × ΔT in Wh
v
= 5820 Wh (for one bath)
To be taken into account for calculating the demand
As per table 4, no. 2 to 4
As existing, incl. any additional facilities according to table 4, no.
6 or 7, if arranged to permit simultaneous use
Not taken into account
Not taken into account
Not taken into account
Per guest room: as existing, according to table 4, no. 1 to 4, with
50 % of the draw-off demand w
As existing, incl. possible additional equipment as per table 4,
no. 5 to 7, with 100 % of the draw-off demand w
At 100 % of the draw-off demand w
At 100 % of the draw-off demand w
DIN code Draw-off volume per use or
available capacity in l
NB1 140
NB2 160
AP 120
GB 200
BRS *8
40
BRN *8
90
BRL *8
180
WT 17
BD 20
HT 9
SP 30
N = total of the heat demand for DHW for all residential units to be
supplied with DHW, divided by the heat demand for DHW for the
standard residential unit
Σ(n · p · v · w )
v
N =
3.5 · 5820
Σ(n · p · v · w )
v
=
20370
n = Number of similar residential units
p = Occupancy factor per similar residential unit
*5
v
v
*6
according to table 4
v
*6
according to table 4
v
Draw-off demand w per
v
use in Wh
5820
6510
4890
8720
1630
3660
7320
700
810
350
1160
DHW heating