Figure Number: Indirect Water Heaters
Niles Steel Tank has many indirect water heaters to choose. All provide superior heat transfer capabilities when used with a boiler or other hydronic heating source such as a heat pump or solar. Our internal coils are designed for low pressure drops and high heat transfer capabilities, which make our indirect water heaters the most efficient on the market. Niles Steel Tank offers, single wall and double wall internal coils, residential and commercial products and stainless steel for areas where aggressive water is present. Choosing the correct indirect water heater for your application is easy. Refer to the list of specifications from the list on the left to help you decide which indirect water heater is right for you.
|Model||Maximum First Hour Rating (Gal/Hr) @||Continous Draw Rating (Gal/ Min) @||Approximate Boiler Output Needed for Ratings (BTU/Hr)|
|Model||Hot Water Availability (minutes)||Coil Heat Transfer Area (Sq. Ft.)||Pressure Drop at 12 GPM (Feet of Head)|
|Model||Tank Capacity (Gal)||Coil Volume (Gal)||Dry Weight (Lbs)||Wet Weight (Lbs)|
Floor to Heater Top
|B.Jacket Diameter||C. |
Height Floor to T&P Conn.
Height Floor to Water Conn.
Height Floor to Exchanger Outlet
Height Floor to Exchanger Inlet
Height Floor to Aquastat
|Approx. Shipping Weight|
|NSW-2-30-L||30||335/8||22||28 3/4||34 3/8||53/8||27 1/2||11 1/2||140|
|NSW-2-40-L||40||36||24||29 3/4||36 3/4||5 3/8||27 1/2||11 1/2||168|
|NSW-2-50-L||50||36||26||29 3/4||36 3/4||5 3/8||27 1/2||11 1/2||196|
|NSW-2-65-L||60||591/4||22||53 1/8||60||5 3/8||27 1/2||11 1/2||196|
|NSW-2-80-L||75||59||24||52 7/8||59 3/4||5 3/8||27 1/2||11 1/2||224|
|NSW-2-120-L||116||621/2||281/4||55 3/4||63 1/4||6 3/8||28 1/4||11 1/2||355|
Stainless Steel Heat Exchanger-Single-wall 1″ O.D. stainless steel coil. Maximum supply temperature from the boiler must not exceed 250°F. Stainless Steel Tank and Heat Exchanger-Made from chromium molybdenum – titanium ferritic 444 stainless steel alloy. Immersed Adjustable Honeywell Aquastat-Fast acting immersion aquastat for automatic temperature control (adjustable from 80°F to 160°F). Supply and Return Connections-3/4″ NPT female connections are located on the front for both the boiler supply and boiler return (1″ NPT on NRTV-119-L). Supply and Return Connections-1″ NPT female connections are located on the front for both the boiler collector supply and return. 2″ Non-CFC Foam Insulation-Covers the side and top of tank, reducing the amount of heat loss. This results in less energy consumption, improved operation efficiencies and jacket rigidity. Potable Water Connections-3/4″ NPT factory installed dielectric fittings extend water heater life and eases installation (11/4″ NPT on NRTV-119). T&P Relief Valve-Included. Steel Jacket Brass Drain/Return Valve. I=B=R Certified-These water heaters are rated by the Institute of Boiler and Radiation Manufacturers (I=B=R) to provide accurate performance data within the standards of the certification. The I=B=R rating is issued by the Hydronics Institute Division of GAMA and provide a recognized standard for proper comparison of hydronic appliances