LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual - Manual (Page 21)

Page 17 N eo T herm Boilers and Water heaters
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 NTV models 150-500 can be ordered with or
without a pump included.
NeoTherm NTH models 80-500 can also 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 connection size
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 2
750 2 750 2
850 2 850 2
Table 9 - Water Connection Pipe Sizes
Section 6A -
WATER CONNECTIONS -
NTH BOILER
Section 6 is divided into two parts. Section
6A covers NTH units designed for hydronic
heating. Section 6B covers NTV models, which
are designed exclusively for “volume water”
domestic hot water applications. Refer to the
proper section for instructions on installing
and piping your product. Refer to Table 9 for
the connection 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.