Nature's Comfort SM-H60 Installation Manual - page 4
Additional Safety Notes, Installing Multiple Systems, Circulation pumps
• The boiler water jacket level must always have water above the solar return port for thermo-siphoning to work
properly.
• Never close valves to the solar heater! If left closed, overheating and damage can occur during daylight hours. At
night the water will eventually cool and contract, developing such a vacuum that it will pull the tubes inward. If they
don’t drop off the end support and break then the manifold’s inner metal shell will implode and be destroyed. The
SM-H60 is a non-pressurized system only and must always be vented and kept full of water that can circulate
freely or be completely empty.
• Keep snow cleaned off the glass tubes using only a soft bristle brush. Never use hard tools or scrapers!
• For those who have larger boiler systems that want to use multiple SM-H60 systems, this may only be done by
putting the solar heaters in parallel. Putting in series can cause overheating, boiling and possibly push a glass tube
out or burst a pex line that could drain the system. Joining the lines together of parallel systems may only be done
at the boiler or storage tank using a fitting assembly. Never run more than 1 system through a 1” PEX loop.
• If a circulation pump is necessary due to a longer distance from the boiler, the pump must produce less than 14psi
(32’ of head) or the glass tubes may be forced out from the manifold because of too much pressure. The Broeder
BN29-7 available only from Nature’s Comfort is designed for this. An aquastat must also be installed at the top of the
manifold to turn the pump on at 130F and off at 125F. This setup is not recommend as pump or electrical failure
can lead to overheating and possibly push a glass tube out or burst a pex line that could drain the system. It is
always best to have the solar heater within 2 - 4 feet of the boiler.
Heat Exchangers
• Install a water to water heat exchanger (available from Nature’s Comfort) on the domestic water heater using a
sidearm type installation (tube & shell). A pre-heater type installation using a plate heat exchanger may also be
utilized but does not work as well during summer use when not firing your boiler because the temperatures of up to
170F produced from the SM-H60 do not get stored in the DHW tank like when using a sidearm type install. See
drawings later in this manual for how to install.
• Plate heat exchangers installed with the “on-demand” type setup (bypassing the domestic water heater) may not be
used for summer use because demand can overcome the solar supply. If you already have this type you must re-
plumb your installation for one of the drawings below or add an additional heat exchanger and plumb bypass
systems in to switch between the two for when firing your boiler or not.
• You must install a water tempering (mixing) valve on the domestic side to prevent scalding water (available from
Nature’s Comfort).
• Note for boiler lines: Always use sweeping bends in the boiler lines as 90 degree fittings add 1’ of head pressure and
will reduce circulation in heat exchangers and the boiler water jacket effecting efficiency. Use ¾” rubber heater hose
for tight radiuses (available from Nature’s Comfort).