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Fröling Energy Tank

All-in-One Thermal Buffer and Indirect Domestic Hot Water Heater

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The Fröling Energy Tank is built differently than typical indirect hot water heaters. Essentially, it is the reverse of a typical indirect hot water heater. The large volume of the storage tank is filled with boiler water. The super efficient 104’ long heat exchanger, with a surface area of 64 square feet, consistently produces domestic hot water with either low buffer or appliance temperatures. Large tappings further increase potential applications for the Energy Tank.

Heating systems are normally designed for the coldest times of the year. However, boilers very rarely have to work at full capacity. For most of the heating period, the average heat consumed is less than 50% of the rated heat output. A storage tank ensures an economic and environmentally-friendly use of energy in spite of boiler sizing difficulties. The buffer holds surplus heat and releases it again to the heat distribution system when required without having to restart the boiler. The Fröling Energy Tank is too small for use on its own with cord wood boilers, but is great for smaller pellet boilers. Used as a domestic hot water tank, the Fröling Energy Tank also offers high performance even with low supply water temperatures.

Fröling Energy Tank
Fröling Energy Tank installed


Advanced Features
The Fröling Energy Tank is the Perfect Buffer Tank for Smaller Pellet Boilers!

Precise temperature stratification in the tank is crucial for optimal functioning. Stratification ensures that as much energy as possible can be re-used by keeping the hottest water at the top of the tank and the coldest water at the bottom. The Fröling Energy Tank features a special stratification baffle designed for this purpose. The extra thick insulation is removable for easier handling of the tank. Heat loss is less than ° Fahrenheit per hour. A sensor bar fixed to the exterior of the tank allows for a large number of sensors at a multitude of locations. The domestic hot water coil is made from 1¼"< corrugated stainless steel. Vortices are formed in the helically corrugated pipe for optimal turbulence and heat transfer, while also eliminating the growth of Legionella and the formation of mineral deposits.

Fröling Layered Tank With and Without Stratification Baffle

Without Stratification Baffle

hot water thermal storage tank heat graph

Diluted temperatures decrease the energy storage capacity of the tank.

With Stratification Baffle

hot water thermal storage tank heat graph hot water thermal storage tank heat graph hot water thermal storage tank heat graph

Actual thermal imaging demonstrates the effectiveness of the stratification baffle. Temperature is strictly separated between hot and cold allowing the boiler to remain off for longer periods. Heat output remains at maximum until energy is completely depleted.

Learn More - Downloadable Brochures

Fröling Energy Tank Brochure

Fröling Energy Tank Brochure - file size 2 Mb

Thermal Storage Brochure

Thermal Storage Planning Guide - file size 1 Mb

Fröling Energy Tank Installation Instructions

Energy Tank Installation Manual - file size 897 Kb

Fröling Energy Tank Features

• One Size 119 Gallon Carbon Steel Tank
• Corrugated Stainless Steel Coil Creates 64 sq ft of Heating Surface
• Removable Insulation Results in Losses Less Than ⅓° Fahrenheit per Hour
• Stratification Baffle Enhances Effectiveness of Stored Heat

• Strategically Sized and Located Tappings
• Perfect for Fröling PE1 model 15/20 or Smaller Pellet Boilers
• Sensor Bar Holds Many Sensors at Various Positions
• 5 Year Warranty - Made by Fröling


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