LAARS NeoTherm NTV600 - Install and Operating Manual - Manual (Page 22)

LAARS Heating Systems
Page 20
NeoTherm's efficiency is higher with lower
return water temperatures. Therefore, to get the most
of low return temperature with multiple boilers, pipe as
shown in
Figures 17-19 .
NeoTherm NTH models can be ordered with or
without a pump included.
NeoTherm with a pump MUST be piped in a
primary-secondary fashion (using either piping or a
hydraulic separator) such that the pump that is mounted
on the boiler ONLY serves the boiler.
When the pump is supplied by Laars, the
NeoTherm boiler must be located within 15 feet (4.6m)
of the supply and return header (or the hydraulic
separator). Pumps supplied by Laars are sized for a
maximum of 30 feet (9.1m) of piping and the headloss
of the boiler only
(see Table 7) .
If longer pipe lengths are required, the pump
should be sized for the boiler per Table 7 and for the
piping it will serve, and should be supplied to job
separately. Even with pumps supplied by others, Laars
strongly recommends primary-secondary piping.
6A.2 NTH Cold Water Make-Up
1. Connect the cold water supply to the inlet
connection of an automatic fill valve.
2. Install a suitable back flow preventer between the
automatic fill valve and the cold water supply.
3. Install shut off valves where required.
The boiler piping system of a hot water heating
boiler connected to heating coils located in air handling
appliances where they may be exposed to refrigerated
air circulation must be equipped with flow control
valves or other automatic means to prevent gravity
circulation of the boiler water during the cooling cycle.
A boiler installed above radiation level, or as
required by the authority having jurisdiction, must be
provided with a low water cutoff device either as a part
of the boiler or at the time of boiler installation.
NTH PIPE SIZE, NTV PIPE SIZE,
SIZE INCHES SIZE INCHES
80 1 – n/a
105 1 – n/a
150 1 150 1¼
210 1¼ 199 1¼
285 1¼ 285 2
399 1¼ 399 2
500 1½ 500 2
600 1½ 600 n/a
750 2 750 n/a
850 2 850 n/a
Table 9. Water Connection Pipe Sizes.
SECTION 6A.
Water Connections - NTH Boiler
Section 6 is divided into two parts. The first is
for NTH models and is Section 6A. The second
is for NTV models and is Section 6B. Refer to
the proper section for instructions in installing
and piping your product. Refer to
Table 9 for
pipe sizes required.
6A.1 NTH System Piping:
Hot Supply Connections
NOTE: This appliance must be installed in a closed
pressure system with a minimum of 12 psi (82.7kPa)
static pressure at the boiler.
Hot water piping should be supported by suitable
hangers or floor stands. Do not support piping with this
appliance. Due to expansion and contraction of copper
pipe, consideration should be given to the type of
hangers used. Rigid hangers may transmit noise through
the system resulting from the piping sliding in the
hangers. It is recommended that padding be used when
rigid hangers are installed. Maintain 1" (2.5cm)
clearance to combustibles for hot water pipes.
Pipe the discharge of the relief valve (full size) to
a drain or in a manner to prevent injury in the event of
pressure relief. Install an air purger, an air vent, a
diaphragm-type expansion tank, and a hydronic flow
check in the system supply loop. Minimum fill pressure
must be 12psig (82.7kPa). Install shutoff valves where
required by code.
Suggested piping diagrams are shown in Figures
15 through 21 . These diagrams are meant only as a
guide. Components required by local codes must be
properly installed.