636486
39
Zoom out
Zoom in
Previous page
1/116
Next page
Engineering information and sizing the heat source
6 720 645 817 (2010/09)
39
5.3 Important hydraulic system components
5.3.1 Hydraulics for maximum utilisation of the
condensing effect
For systems where the heating circuits are connected via
a low loss header, we recommend that the pump is
controlled subject to boiler output. This operating
principle enables the system to operate with maximum
utilisation of the condensing effect.
5.3.2 Underfloor heating system
Due to their low design temperatures, underfloor
heating systems are ideal for combination with a
Suprapur gas condensing boiler. Due to the inertia
during heat-up, we recommend weather-compensated
operation combined with a separate flow
rate-dependent room temperature controller. In
conjunction with the boiler control unit, the FW ...
controllers are suitable for this purpose.
A temperature limiter is required to protect the
underfloor heating system. It should be connected to the
IPM ... For the temperature limiter, contact thermostat
TB 1 can be used, for example.
Automatic system-controlled screed drying is not
possible here, and should therefore be allowed for on
site. Automatic screed drying with the FW ... controller is
only possible via an underfloor heating circuit with
mixer.
5.3.3 Diaphragm expansion vessel
In accordance with DIN EN 12828, water heating
systems must be equipped with a diaphragm expansion
vessel (MAG).
Rough guide to selecting a diaphragm expansion vessel
1. MAG pre-charge pressure
Form. 3 Formula for the MAG pre-charge pressure
(minimum 0.5 bar)
p
0
Pre-charge pressure of the MAG in bar
p
st
Static pressure of the heating system in bar (subject to
building height)
2. System fill pressure
Form. 4 Formula for the system fill pressure
(minimum 1.0 bar)
p
a
System fill pressure in bar
p
0
Pre-charge pressure of the MAG in bar
3. System volume
Subject to various heating system parameters, the
system volume can be checked on the graph in Fig. 25.
4. Maximum permissible system volume
Subject to a maximum flow temperature to be set ϑ
V
and
the pre-charge pressure determined according to
formula 3 p
0
of the MAG, the permissible maximum
system volume for various MAG can be checked in
table 19.
The system volume checked acc. to point 3 in Fig. 25
must be smaller than the maximum permissible system
volume. Select a larger diaphragm expansion vessel if
that is not the case.
Example 1
Given
n System output Q
K
= 200 kW
o Underfloor heating/radiators
Actual
p Total system water content = 4000 l
(Æ Fig. 25, curve a)
Fig. 25 Standard values for average water content of
heating systems
a Underfloor heating system and steel/cast iron radiators
with pipes sized for gravity circulation (20 l/kW)
b Panel radiators (10 l/kW)
c Convectors (6 l/kW)
V
A
Average total water content
Q
K
Rated output
Always use the Suprapur gas condensing
boilers with a low loss header.
p
0
p
st
=
p
a
p
0
0.5 bar+=
.
0
1
2
3
4
5
6
7
8
9
10
11
12
0 100 200 300 400 500 600
a
b
c
V
A
/ m
3
Q
K
/ kW
.
6 720 643 417-29.1O
.
39


Need help? Post your question in this forum.

Forumrules


Report abuse

Libble takes abuse of its services very seriously. We're committed to dealing with such abuse according to the laws in your country of residence. When you submit a report, we'll investigate it and take the appropriate action. We'll get back to you only if we require additional details or have more information to share.

Product:

For example, Anti-Semitic content, racist content, or material that could result in a violent physical act.

For example, a credit card number, a personal identification number, or an unlisted home address. Note that email addresses and full names are not considered private information.

Forumrules

To achieve meaningful questions, we apply the following rules:

Register

Register getting emails for Junkers MKB 400-3 A at:


You will receive an email to register for one or both of the options.


Get your user manual by e-mail

Enter your email address to receive the manual of Junkers MKB 400-3 A in the language / languages: English as an attachment in your email.

The manual is 15,83 mb in size.

 

You will receive the manual in your email within minutes. If you have not received an email, then probably have entered the wrong email address or your mailbox is too full. In addition, it may be that your ISP may have a maximum size for emails to receive.

The manual is sent by email. Check your email

If you have not received an email with the manual within fifteen minutes, it may be that you have a entered a wrong email address or that your ISP has set a maximum size to receive email that is smaller than the size of the manual.

The email address you have provided is not correct.

Please check the email address and correct it.

Your question is posted on this page

Would you like to receive an email when new answers and questions are posted? Please enter your email address.



Info