## IF YOU HAVE A TANK, YOU NEED HEAT EXCHANGERS.

### Testing and Performance Prove STSS Copper Heat Exchange Coils are and important component for storing heat in water and distribution from storage.

You May Ask Why?

- STSS copper heat exchangers are designed and engineered to transfer heat efficiently at low temperatures. Engineering criteria becomes more critical as working temperatures drop.
- Testing performed by Bucknell University, Engineering Department, over a period of two years verified the performance characteristics of our design. Out unique design and the shape of the coil itself account for over 20% of its superior performance. This design breaks up adhesion and increases heat transfer rates during the time of contact without turbulators and without increasing head pressure for the designated length of copper.
- Self-purging on startup in space heating applications.
- These coils create and maintain near perfect tank stratification.
- Available in four sizes to meet the needs of solar, wood-burning, and off-peak electric markets for both space heating and domestic hot water applications.

### Copper Heat Exchanger Coil

Specifications:

Copper Tube 3/4″ Inch L-Soft

Configuration Diameter: 20 Inches

Height: 43 Inches

Spiral Vertical

**DESCRIPTION**

Part No. 421 Two Coils. Stacked vertically. Bottom 60 Feet. Top 120 Feet.

424 Two Coils. Stacked vertically. Bottom 90 Feet. Top 120 Feet.

425 One Coil. 120 Feet.

427 One Coil. 180 Feet.

**RATINGS**

Solar Input Ratings:

Part No. 421 60 Foot bottom coil is designed for up to 3 4X8 ft. flatplate collectors.

424 90 Foot bottom coil is designed for up to 5 4X8 ft. flatplate collectors.

425 2 – 120 Foot single coils are designed for up to 13 4X8 ft. flat plate collectors.

Domestic Hot Water Output Ratings:

Part No. 425 Temperature rise from 47 Deg. F. to 105 Deg F. @ 2 GPM.

Average tank temperature 120 Deg. F.

Transfer rate 57,976 BTU½”s per hour.

427 Temperature rise from 47 Deg. F. to 105 Deg. F. @ 3 GPM.

Average tank temperature 120 Deg. F.

Transfer rate 86,965 BTU½”s per hour.

Space Heating Output Ratings:

Part No. 425 1 ½” 120 Foot coil. 26,400 BTUï¿½s @ average tank temperature of 120 Deg. F.

2 ½” 120 Foot coils. 52,800 BTU’s @ average tank temperature of 120 Deg. F.

427 1½” 180 Foot coil. 39,600 BTU’s @ average tank temperature of 120 Deg. F.

2 ½” 180 Foot coils. 79,200 BTU’s @ average tank temperature of 120 Deg. F.

Approximate Flow Rates and Head:

Part No. 424 1½” 90 Foot coil. 6 GPM results in 9 feet of head.

1 ½” 120 Foot coil. 6 GPM results in 10 feet of head.

427 1 ½” 180 Foot coil. 5 GPM results in 12 feet of head.

### STSS Copper and PEX Heat Exchanger Coils

To meet the needs of the Solar and Woodburning, In-Floor Radiant Heat and Domestic Hot Water Heating Markets.

- At STSS CO INC we realized the necessity to have a heat exchanger coil that would Perform on a par with copper but without the high cost. For that reason we designed, engineered and tested a heat exchanger constructed of a mixture of copper tubing and specialized PEX tubing that is oxygen-inhibited, cross linked, high density polyproethylene. This tubing has good high temperature and pressure characteristics. It will withstand, overtime, 180 Degrees F. temperatures and 100 pound pressure without deforming or expanding.
- Testing was conducted using a 328 gallon STSS heat storage tank, heated to 173 Degrees F. The heat exchange coil was placed in the tank and connected to the city water system. Incoming city water temperature was 58 Degrees F. A flow rate through the coil of 2.5 GPM was established.

The test was continued and monitored every five minutes for 215 minutes with the goal to heat the water coming out of the heat exchanger to 87 Degrees F. from city water coming in at 58 DegreesF. When the test was completed, the tank temperature was then 96.8 Degrees F. The mathematical results of this test showed the Btu output of this heat exchanger, based on the following 5 tank temperatures:

1. 8.33 x 2.5 GPM x 60 Minutes x 88 Delta T = 109,956 Btu’s per hour.

Tank temperature at 173 Degrees F.

2. 8.33 x 2.5 GPM x 60 Minutes x 70 Delta T = 87,465 Btu’s per hour.

Tank temperature at 150 Degrees F.

3. 8.33 x 2.5 GPM x 60 Minutes x 54 Delta T = 67,473 Btu’s per hour.

Tank temperature at 130 Degrees F.

4. 8.33 x 2.5 GPM x 60 Minutes x 47 Delta T = 58,726 Btu’s per hour.

Tank temperature at 120 Degrees F.

5. 8.33 x 2.5 GPM x 60 Minutes x 39 Delta T = 48,750 Btu’s per hour.

Tank temperature at 110 Degrees F.

- These coils are self-purging at start-up in space heating applications and they create and maintain near perfect tank stratification.

### Copper and PEX Combined

### Specifications:

Copper Tube With PEX Configuration

- ï3/4 Inch L-Soft
- ï3/4 Inch Oxygen Inhibited, Cross-Linked-High-Density Polyethylene (PEX)
- Diameter: 21 Inches
- Height: 42 Inches
- Vertical Spiral

### Description

Part No CUP420

- Combination Copper and PEX in Copper Cage.
- The length of copper in relationship to PEX will vary by application.

### Ratings

#### Domestic Hot Water Output Ratings:

- Temperature rise from 58 Deg. F. to 146 Deg. F. @ 2.5 GPM.<![endif]>
- Average tank temperature 172 Deg. F., 109,956 Btu’s per hour.

- Temperature rise from 58 Deg. F. to 123 Deg. F. @ 2.5 GPM.
- Average tank temperature 145 Deg. F., 81,218 Btu’s per hour.

- Temperature rise from 58 Deg. F. to 97 Deg. F. @ 2.5 GPM.
- Average tank temperature 120 Deg. F., 48,730 Btu’s per hour.

#### Space Heating Output Ratings:

- 1 ï3/4 CUP420 Coil 37,485 Btu’s @ average tank temperature of 110 Deg. F.
- 2 ï3/4 CUP420 Coils 74,970 Btu’s @ average tank temperature of 110 Deg. F.

#### Approximate Flow Rates and Head:

- 1 ï¿½ CUP420 Coil 4 GPM results in 8 feet of head pressure.
- 1 ï¿½ CUP420 Coil 5 GPM results in 12 feet of head pressure.