Commercial Hydronic Radiators

Model  UFLT

Low Surface Temp: Double Sided or Curtain Wall

Low Surface Temperature Radiators: UFLT

Where surface temperature is a concern, such as in schools, daycares, hospitals, or public spaces, order low surface temperature radiators. These models are perimeter systems with a second layer of inactive tubes in front of the heating tubes. This reduces the front panel temperature by as much as 20 to 30⁰F less than the average water temperature. Due to their physical configuration, these units are both radiant and convective.

Product Specifications

General:

Provide UFLT steel panel radiator elements of lengths and in locations as indicated, and of capacities, style and having accessories as scheduled. The wall hung heating panel radiation shall be of one-piece all-welded steel construction, consisting of flattened water tubes welded to headers at each end. The radiator shall include an integral heavy gauge (0.09” minimum) all-welded perforated top grille. UFLT models to have steel corrugated fins welded to the active water tubes to increase the convective output of the unit. There shall be no less than 32 fins per foot. Fins shall start within 1” of the headers, and shall be spot-welded three times per tube. In addition, there shall be an inactive set of tubes on the front side of the UFLT, so that the front and rear sides of the UFLT look the same.

The radiator’s headers shall include all necessary inlet, outlet and vent connections as required. Standard connection sizes are 1/2” NPT tapered thread for supply and return piping, and 1/8” for the vent connection.

The radiant heating panels shall be available in lengths from 2’-0” to 24’-0” in six inch even increments from 2’-0” to 4’-0”, and in one foot increments from 4’-0” to 24’-0”. The panel radiation shall be capable of being mounted to typical stud wall construction without additional blocking or strapping. Appropriate wall mounting brackets or optional floor post mounting shall be provided with the radiation. Panel radiation expansion shall not exceed 1/64” per foot of radiation at 215ºF. The installer shall provide adequate expansion compensation for each radiator.

The panel radiation shall be manufactured in the USA.

 

Pressure Ratings:

Pressure ratings for the radiation shall be as follows:

STANDARD: Working pressure-56 PSI maximum, Test Pressure-74 PSI maximum

OR

HIGH: Working pressure-128 PSI maximum, Test Pressure 184 PSI maximum

 

Finishes:

The panel radiation shall be cleaned and phosphatized in preparation for the powder coat finish. The radiation is then finish painted with a gloss powder coat finish, for a total paint thickness of 2-3 mils (0.002” – 0.003”). The color shall be selected from Runtal’s ten Standard Colors; or Runtal Optional Colors shall be available at and additional cost.

 

Warranty:

All Runtal radiators are covered by a 5-Year Limited Warranty.

 

Manufacturer:

Subject to compliance with requirements, provide flat tube panel radiation as manufactured by Runtal North America, Inc.

 

OPTIONAL ITEMS WHICH MAY BE ADDED TO THE SPECIFICATION:

  1. Ribbed pipe cover trims, finished to match the radiators shall be provided with the radiation.
  2. The radiation manufacturer shall provide combination shutoff valve/union fitting of less than two inches in width for the supply and return to each panel radiator, to be field installed by others.
  3. Runtal-Flex connectors shall be used where appropriate to provide expansion compensation for the radiators.

 

Model Type UFLT
Quick Specifications

Panel Radiator Specification

1. Radiators are manufactured of cold rolled low carbon steel, fully welded and consisting of header pipes at each end, connected by flat oval water tubes.
2. Three tube thicknesses are available:
Standard Pressure – 0.048″ min wall thickness
High Pressure – 0.078″ min wall thickness
3. Radiator header pipes are square 0.109″ min wall thickness and include all necessary supply, return, and air vent connections. Internal baffling is provided as required.
4. Standard piping connections are 1/2″ NPT taper threaded sockets, located in either side, or vertical positions. Optional 3/4″ NPT connections are available. Air vent connections are 1/8″ NPT taper threaded sockets.
5. Three working pressures are available:
Standard Pressure – 56 psi max (Tested at 74 psi)
High Pressure – 128 psi max (Tested at 184 psi)
6. Radiator expansion does not exceed 0.016 inch per linear foot at 215°F. Expansion compensation to be provided in the piping as required, by others.
7. Radiators are cleaned and phosphatized in preparation for the powder coat finish.
8. Radiators are painted with a gloss powder coat finish, for a total paint thickness of 2 to 3 mils (0.002″-0.003″). In harsh environments, anti-corrosion finish paint should be specified.
9. Color of the finish paint shall be selected from available standard or optional colors prior to ordering.
10. Wall mounting brackets are provided with radiators, unless floor posts are specified.
11. Necessary wall support blocking for proper radiator mounting shall be by others.
12. Radiators are manufactured in the USA to the sizes, capacities, and quantities as shown on the plans and schedules.

Product Specifications (PDF)

BTUH/ft Ratings

Energy efficient as well as space saving. The UFLT combines the output of a UF radiator with an inactive front panel, making the UFLT perfect for spanning window mullions or where a lower temperature front face is desired. Various average water temperatures (AWT) are shown here for convenience, but for more specific conditions use the appropriate correction factor with the 215°F rating. Please see the technical pages for the correction factor best suited to the design conditions.
BTUH/ft Ratings @ 65°F EAT
MODEL HEIGHT inches DEPTH inches 215°F 180°F 140°F
UFLT-2 5.7 1.6 867 610 349
UFLT-3 8.6 1.6 1118 787 451
UFLT-4 11.5 1.6 1351 951 544
UFLT-5 14.4 1.6 1718 1209 692

Overview (PDF)

Heating Capacity

Model Type UFLT
BTUH/ft Ratings



Technical Data For All UFLT Models Is Included Below

MODEL
TYPE
HEIGHT
H
BTUH/FT OUTPUT @ LISTED AWT & 65°F EAT DRY WT
lbs/ft
215°F 190 180 170 160 150 140 130 120
                       
UFLT-2 5-3/4″ 867 680 610 542 476 411 349 290 233 5.6
UFLT-3 8-5/8″ 1118 878 787 699 613 530 451 374 300 8.6
UFLT-4 11-1/2″ 1351 1060 951 844 741 641 544 452 363 11.7
UFLT-5 14-3/8″ 1718 1348 1209 1073 942 815 692 574 461 15.6

NOTE: Heat Outputs for various AWT’s include 15% Heat Effect for placement along outside walls. Use the 215° F Output Rating with the Correction Factor for more specific design conditions. High Pressure increases Dry Weight by 15%.

Heating Capacity (PDF)

Correction Factors

Correction Factors

EAT
AWT 45°F 50°F 55°F 60°F 65°F 70°F 75°F 80°F 85°F 90°F 95°F
240°F 1.365 1.350 1.304 1.266 1.220 1.171 1.124 1.086 1.039 1 0.953
235°F 1.343 1.305 1.267 1.219 1.171 1.124 1.086 1.038 1 0.952 0.910
230°F 1.305 1.267 1.219 1.171 1.124 1.086 1.038 1 0.952 0.910 0.868
225°F 1.267 1.219 1.171 1.124 1.086 1.038 1 0.952 0.910 0.868 0.826
220°F 1.219 1.171 1.124 1.086 1.038 1 0.952 0.910 0.868 0.826 0.785
215°F 1.171 1.124 1.086 1.038 1 0.952 0.910 0.868 0.826 0.785 0.744
210°F 1.124 1.086 1.038 1 0.952 0.910 0.868 0.826 0.785 0.744 0.704
205°F 1.086 1.038 1 0.952 0.910 0.868 0.826 0.785 0.744 0.704 0.664
200°F 1.038 1 0.952 0.910 0.868 0.826 0.785 0.744 0.704 0.664 0.625
195°F 1 0.952 0.910 0.868 0.826 0.785 0.744 0.704 0.664 0.625 0.587
190°F 0.952 0.910 0.868 0.826 0.785 0.744 0.704 0.664 0.625 0.587 0.549
185°F 0.910 0.868 0.826 0.785 0.744 0.704 0.664 0.625 0.587 0.549 0.511
180°F 0.868 0.826 0.785 0.744 0.704 0.664 0.625 0.587 0.549 0.511 0.474
175°F 0.826 0.785 0.744 0.704 0.664 0.625 0.587 0.549 0.511 0.474 0.438
170°F 0.785 0.744 0.704 0.664 0.625 0.587 0.549 0.511 0.474 0.438 0.403
165°F 0.744 0.704 0.664 0.625 0.587 0.549 0.511 0.474 0.438 0.403 0.369
160°F 0.704 0.664 0.625 0.587 0.549 0.511 0.474 0.438 0.403 0.369 0.334
155°F 0.664 0.625 0.587 0.549 0.511 0.474 0.438 0.403 0.369 0.334 0.301
150°F 0.625 0.587 0.549 0.511 0.474 0.438 0.403 0.369 0.334 0.301 0.269
145°F 0.587 0.549 0.511 0.474 0.438 0.403 0.369 0.334 0.301 0.269 0.237
140°F 0.549 0.511 0.474 0.438 0.403 0.369 0.334 0.301 0.269 0.237 0.207
135°F 0.511 0.474 0.438 0.403 0.369 0.334 0.301 0.269 0.237 0.207 0.177
130°F 0.474 0.438 0.403 0.369 0.334 0.301 0.269 0.237 0.207 0.177 0.149
125°F 0.438 0.403 0.369 0.334 0.301 0.269 0.237 0.207 0.177 0.149 0.122
120°F 0.403 0.369 0.334 0.301 0.269 0.237 0.207 0.177 0.149 0.122 0.096
115°F 0.369 0.334 0.301 0.269 0.237 0.207 0.177 0.149 0.122 0.096 0.071
110°F 0.334 0.301 0.269 0.237 0.207 0.177 0.149 0.122 0.096 0.071 0.50
105°F 0.301 0.269 0.237 0.207 0.177 0.149 0.122 0.096 0.071 0.50 0.030
100°F 0.269 0.237 0.207 0.177 0.149 0.122 0.096 0.071 0.50 0.030 0.011
EXAMPLE: To find the BTUH/ft Rating for an RF-4 Panel at 145°F AWT and 65°F EAT, Multiply the Correction Factor (0.438) by the BTUH/ft Rating at 215°F (1351), e.g. (0.438) X (1351) = 592 BTUH/ft

Correction Factors (PDF)

Flow Rates

How To Determine Flow Rates

The flow rate through a Runtal radiator (or series of radiators) is dependent on the length of the radiator (or combined length of the radiator series), and the design Entering Water Temperature (EWT) and the design Leaving Water Temperature (LWT).

The designer picks the design EWT and LWT. For example, he might pick 170°F as the EWT and 150°F as the LWT. The median point between these two temperatures is called the Average Water Temperature (AWT), and in this example the AWT is 160°F.

The Runtal Heating Capacity charts are based on the heating capacity per foot of radiator, based on the designer’s chosen AWT, and this heating capacity per foot is expressed in units of BTUH/FT @ a given AWT. The required flow rate (GPM) is figured as follows:

Flow Rate = (Heating Capacity/Foot X Radiator Length)

DT –LWT) X 500]

The (EWT – LWT) is commonly referred to as the “Delta T”, or “DT”.

Therefore, our Flow Rate formula becomes:

GPM = (BTUH/FT X FT of Radiator) DT (DT X 500)

As an example, let’s say our designer needs 445 BTUH/FT capacity, over a
10′-0″ span of wall, and has chosen the design water temperatures as EWT = 170°F, and LWT = 150°F. This means our AWT is 160°F. Looking in the Runtal type “R” radiator Heating Capacity chart, we see that an R-4 radiator gives us the required 445 BTUH/FT at 160°F AWT. Therefore, the required flow rate for the 10′-0″ long R-4 radiator is:

GPM = (445 BTUH/FT X 10FT) DT (20°F DT X 500) = 0.445 GPM

Note that there are various combinations of EWT and LWT that can result in the same AWT. In our example above, for instance, a 180°F EWT and a 140°F LWT result in the same 160°F AWT. With Runtal’s unique flattened water tube design, Delta T’s of up to 60°F are possible without concern that the flow rate is too low for heat transfer.

As for a maximum flow rate for Runtal radiators, we recommend no more that 1.5 GPM per water tube. For our R-4 example above, this would mean a maximum flow rate of 6 GPM for an opposite end piped radiator, or 3 GPM for a same end piped radiator.

 

Piping Options

Piping Options

A Type Connections

Type
Supply Left
A Type
Supply Right
B Type Connections

Type
Supply Left
B Type
Supply Right
C Type Connections

C Type
Supply Left
C Type
Supply Right
D Type Connections

D Type
Supply Left
D Type
Supply Right
Opposite End Series

NOTES:

  • Air Vent standard on the Return side of each Panel
  • Lower Pressure Drop than Same End Series
  • Up to 7 Radiators (100 ft) in an Opposite End Series
  • Expansion Compensation Piping is Recommended
Same End Series

NOTES:

  • Same AWT over the entire Same End Series
  • Can Eliminate Costly Risers
  • Higher Pressure Drop than Opposite End Series
  • No More than 3 Radiators in a Same End Series
  • Expansion compensation Piping is Recommended

Piping Options (PDF)

Pressure Drop: Opposite End

Model Type UFLT
Pressure Drop: Opposite End

RADIATOR PRESSURE DROP – FOOT OF HEAD PER RADIATOR

 

RADIATOR MODEL
NUMBER OF TUBES FOR FLOW

CONNECTION PD

PER CONNECTION

STD
PRESSURE
TUBE

UFLT-2 UFLT-3 UFLT-4 UFLT-5 1/2″
CONN
PD
2 3 4 5
             
  0.05 0.05 0.02 0.01 0.01 0.01
  0.75 0.12 0.05 0.03 0.02 0.01
  1.00 0.21 0.09 0.05 0.04 0.03
  1.50 0.45 0.21 0.12 0.08 0.04
  2.00 0.79 0.36 0.21 0.13 0.06
  2.50 1.21 0.55 0.32 0.21 0.08
  3.00 1.72 0.79 0.45 0.29 0.10
  3.50 2.32 1.06 0.61 0.40 0.15

GPM

4.00 3.00 1.37 0.79 0.51 0.18
  4.50 3.76 1.72 0.99 0.64 0.20
  5.00 4.61 2.11 1.21 0.79 0.25
  5.50 5.54 2.53 1.45 0.95 0.28
  6.00 6.56 3.00 1.72 1.12 0.33
  6.50 7.65 3.50 2.01 1.31 0.37
  7.00 8.83 4.04 2.32 1.51 0.42
  7.50 10.08 4.61 2.65 1.72 0.50
  8.00 11.42 5.22 3.00 1.95 0.56
             
MED
PRESSURE
TUBE
         
             
  0.50 0.12 0.06 0.03 0.02 0.01
  0.75 0.26 0.12 0.07 0.04 0.01
  1.00 0.46 0.21 0.12 0.08 0.03
  1.50 1.00 0.46 0.26 0.17 0.04
  2.00 1.75 0.80 0.46 0.30 0.06
  2.50 2.69 1.23 0.71 0.46 0.08
  3.00 3.83 1.75 1.00 0.65 0.10
  3.50 5.16 2.36 1.35 0.88 0.15

GPM

4.00 6.67 3.05 1.75 1.14 0.18
  4.50 8.37 3.83 2.20 1.43 0.20
  5.00 10.26 4.69 2.69 1.75 0.25
  5.50 12.33 5.64 3.24 2.10 0.28
  6.00 14.59 6.67 3.83 2.49 0.33
  6.50 17.03 7.79 4.47 2.90 0.37
  7.00 19.65 8.98 5.16 3.35 0.42
  7.50 22.44 10.26 5.89 3.83 0.50
  8.00 25.42 11.62 6.67 4.34 0.56
             
HIGH
PRESSURE
TUBE
         
             
  0.50 0.22 0.10 0.06 0.04 0.01
  0.75 0.47 0.22 0.12 0.08 0.01
  1.00 0.82 0.38 0.22 0.14 0.03
  1.50 1.79 0.82 0.47 0.31 0.04
  2.00 3.13 1.43 0.82 0.53 0.06
  2.50 4.81 2.20 1.26 0.82 0.08
  3.00 6.84 3.13 1.79 1.17 0.10
  3.50 9.21 4.21 2.42 1.57 0.15

GPM

4.00 11.91 5.45 3.13 2.03 0.18
  4.50 14.96 6.84 3.92 2.55 0.20
  5.00 18.33 8.38 4.81 3.13 0.25
  5.50 22.03 10.07 5.78 3.76 0.28
  6.00 26.06 11.91 6.884 4.45 0.33
  6.50 30.41 13.91 7.98 5.19 0.37
  7.00 35.09 16.04 9.21 5.99 0.42
  7.50 40.08 18.33 10.52 6.84 0.50
  8.00 45.40 20.76 11.91 7.75 0.56

RADIATOR PRESSURE DROP IS FOR THE ENTIRE RADIATOR; IT IS NOT PER FOOT OF RADIATOR

Pressure Drop: Opposite End (PDF)

Pressure Ratings

Pressure ratings for the radiation shall be as follows:

STANDARD: Working pressure-56 PSI maximum, Test Pressure-74 PSI maximum
HIGH: Working pressure-128 PSI maximum, Test Pressure 184 PSI maximum

Detailed Specifications (PDF)

Mounting Systems

K12LT Bracket Assembly

Mount to UFLT tubes

Mount to wall studs, window mullions,
or other suitable supports


UFLT-2

Overview (PDF)

Wall Mounting

Model Type UFLT
Wall Mounting

For Radiators

20″ to 60″ Long – Use 4 K12LT Brackets, one at each end

62″ to 138″ Long – Use 6 K12LT Brackets, one at each end, one in the middle

140″ to 236″ Long – Use 8 K12LT Brackets, one at each end, two distributed evenly in the middle

MOUNTING SYSTEMS

K12LT Bracket Assembly

 

Mount to UFLT tubes

 

Mount to wall studs, window mullions,
or other suitable
supports


UFLT-2

Wall Mounting (PDF)

Colors & Finishes

The panel radiation shall be cleaned and phosphatized in preparation for the powder coat finish. The radiation is then finish painted with a gloss powder coat finish, for a total paint thickness of 2-3 mils (0.002” – 0.003”). The color shall be selected from Runtal’s ten Standard Colors; or Runtal Optional Colors shall be available at and additional cost.

Detailed Specifications (PDF)

Color Options 

Warranty

All Runtal radiators are covered by a 5-Year Limited Warranty.

Warranty (PDF)

Radiator Installation Instructions

  1. Radiators are boxed together in as few crates as possible. A box of brackets is included as a separate piece, and it is marked to denote brackets. Inside the crates, each panel is wrapped in foam sheeting. Saving this foam to re-wrap the panel once it is wall mounted will protect it from construction site damage.
  2. Each radiator is tagged with a label that indicates the project name, model type, color, connection code, bracket type & quantity and tag number. The tag number will usually designate a floor level and room number for easier placement on the job. Locate each radiator as required.
  3. Carefully place each radiator face down on a smooth level surface (e.g. floor or table). Distribute the K12 wall brackets for each radiator. The tag on the radiator indicates the quantity of brackets. Mount the brackets securely on wall studs, spacing them as evenly as possible at 2 to 4 feet apart, with a bracket at least 12 inches from each end of the panel. Allow a minimum of 3 inches below each panel radiator to facilitate cleaning and to assure proper output. For baseboard models, 2 inches or even 1 inch above the floor is permissible with little loss of heat output.
  4. RADIATORS WITH FINS (BACK SIDE OF PANEL)
    With the radiator face down, attach each K12 clip to the fins at the stud location. With the radiator still face down, thread the K45 offset bolts (5/16” carriage bolts) into the bottom threaded positions with a crescent wrench. Once the bolts have cleared the paint away, they should turn easily by hand. Attach the K12 bracket to the wall stud with 2 lag bolts. Hang the panel onto the brackets to determine if the K45 offset bolts are properly adjusted. Check that the panel is level.
  5. RADIATORS (NO FINS ON BACK SIDE OF PANEL)
    With the radiator face down, attach each K12 clip to the radiator’s perforated steel mounting channel at the K12 stud locations. With the radiator still face down, thread the K45 offset bolts (5/16” carriage bolts) into the bottom threaded positions with a crescent wrench. Once the bolts have cleared the paint away, they should turn easily by hand. Hang the panel onto the brackets to determine if the K45 offset bolts are properly adjusted. Check that the panel is level.
  6. Remove the radiator from the wall, and thread the supply and return fittings into the connections on the panel. The sealing tape or pipe dope used is the installer’s choice – make sure the connections are leak tight. One quarter of a turn past hand tight is usually sufficient. Use the foam wrap as a pad for the face of the panel while tightening up the fittings. Each radiator needs to be fitted with a 1/8” air vent prior to startup.
  7. FLOOR POST & PEDESTAL MOUNTED RADIATORS
    When using floor posts, each post must line up with a corresponding K45 offset bolt attached to the back side of the radiator. Using this spacing as a guide, securely fasten each floor post to the floor, using appropriate fasteners. The K12 wall bracket is attached to the floor post, and the K12 clip to the radiator, as described in step #4. The nut and bolt used to attach the K12 bracket to the floor post is to be supplied by others.
    For pedestal mounting, the pedestals should be arranged so that the end pedestals sit within 12 inches of each end of the radiator, with the remainder spaced evenly along the radiator’s length. Each pedestal should be securely fastened to the floor using appropriate fasteners. Radiators sit on the pedestals, with the “fingers” of the pedestals sticking up between the fins to provide stability.
  8. Radiators expand a maximum of 0.016 inch per linear foot of length if heated to 215°F. Piping attached to the radiator must provide the necessary expansion compensation.
  9. Once the radiators are installed, the system can be tested to 50 psi. DO NOT OVER-PRESSURIZE THE RADIATORS as permanent damage may be done.
    • Standard Pressure Panels: Maximum 56 psi
    • High Pressure Panels: Maximum 128 psi
    • When the system has been shown to hold 50 psi maximum air, the piping and radiators can be filled with water. As water fills the system and radiators, air is forced to the vent fittings. Vent as much air as possible before turning on the circulating pump(s).
  10. When the system is filled, operate the circulator(s) to force the remaining air to the high points of the system. With the system pressurized, turn off the circulator(s) to vent the panels. Each radiator should be individually bled of air. Once cold venting has been completed, heat the system to design temperature and repeat the venting procedure as many times as necessary to remove all air from the system.

Radiator Installation Instructions (PDF)

Operation & Maintenance

  1. Radiators are manufactured in the USA of cold rolled low carbon steel and should be used only in closed closed hydronic systems to assure no corrosion of any system components.
  2. Proper radiator operation depends on adequate flow of water to the panel, which can only be accomplished when all the system air has been fully vented from the panels.
  3. Radiators should each be vented, with the system pressurized but in a static state (pumps off). Venting may need to be done periodically to assure a closed system.
  4. DO NOT OVER-PRESSURIZE RADIATORS:
    Most radiators are standard pressure construction. Standard pressure radiators should be tested with NO MORE THAN 50 PSI.
  5. Radiator Operating Pressure Ratings:
    Standard Pressure – 56 psi max (Tested at 74 psi)
    High Pressure – 128 psi max (Tested at 184 psi)
  6. Radiators expand a maximum of 0.016 inch per linear foot of length if heated to 215°F. Piping attached to the radiator must provide the necessary expansion compensation.
  7. Flexible piping and elbowed piping are two simple ways to provide the 1/8 inch to 1/2 inch (typical) of flexibility required in expansion situations (usually series piping).
  8. Runtal Radiators require less flow rate than other hydronic heating products. If flow noise is apparent, balance the system until the noise is reduced.
  9. For a delta T of 20°F. (T supply minus T return), divide the total Btu/hr capacity of the loop by 10,000. This gives the Flow Rate in gallons per minute (GPM)
  10. Many levels of control are available today for hydronic systems. Runtal Radiators will provide nice, even heating whether operated by a simple thermostat to baseboard loop system, or an advanced boiler reset controller with motorized mixing valves, constant circulation and 2-pipe distribution.

Operation & Maintenance (PDF)

Radiator Maintenance

  1. Hydronic system maintenance should include routine checks for piping leaks (usually indicated by frequent makeup water), and a yearly diagnosis of the system water pH to evaluate its corrosive potential.

  2. Internal radiator maintenance depends entirely on the system water makeup and proper venting. Hydronic system additives are available to passivate and protect against freezing. These additives will not significantly reduce the output of Runtal Radiators.

  3. External radiator maintenance consists of keeping the surfaces clean, and any paint nicks or deep scratches painted with touch-up to prevent any surface rust.

  4. Radiators can be painted after sanding with fine grit paper to dull the high gloss and by wiping with solvent or a tack rag. Use only oil-based enamel paint (alkyd, acrylic, urethane, epoxy) – do not use latex or lacquer paint. Use urethane or epoxy enamel for radiators located in harsh environments. Spray the paint to achieve an even coating, and let dry completely before heating the radiator.

 

Operation & Maintenance (PDF)

Product Specifications

General:

Provide UFLT steel panel radiator elements of lengths and in locations as indicated, and of capacities, style and having accessories as scheduled. The wall hung heating panel radiation shall be of one-piece all-welded steel construction, consisting of flattened water tubes welded to headers at each end. The radiator shall include an integral heavy gauge (0.09” minimum) all-welded perforated top grille. UFLT models to have steel corrugated fins welded to the active water tubes to increase the convective output of the unit. There shall be no less than 32 fins per foot. Fins shall start within 1” of the headers, and shall be spot-welded three times per tube. In addition, there shall be an inactive set of tubes on the front side of the UFLT, so that the front and rear sides of the UFLT look the same.

The radiator’s headers shall include all necessary inlet, outlet and vent connections as required. Standard connection sizes are ó” NPT tapered thread for supply and return piping, and 1/8” for the vent connection.

The radiant heating panels shall be available in lengths from 2’-0” to 24’-0” in six inch even increments from 2’-0” to 4’-0”, and in one foot increments from 4’-0” to 24’-0”. The panel radiation shall be capable of being mounted to typical stud wall construction without additional blocking or strapping. Appropriate wall mounting brackets or optional floor post mounting shall be provided with the radiation. Panel radiation expansion shall not exceed 1/64” per foot of radiation at 215ºF. The installer shall provide adequate expansion compensation for each radiator.

The panel radiation shall be manufactured in the USA.

 

Pressure Ratings:

Pressure ratings for the radiation shall be as follows:

STANDARD: Working pressure-56 PSI maximum, Test Pressure-74 PSI maximum

OR

HIGH: Working pressure-128 PSI maximum, Test Pressure 184 PSI maximum

 

Finishes:

The panel radiation shall be cleaned and phosphatized in preparation for the powder coat finish. The radiation is then finish painted with a gloss powder coat finish, for a total paint thickness of 2-3 mils (0.002” – 0.003”). The color shall be selected from Runtal’s ten Standard Colors; or Runtal Optional Colors shall be available at and additional cost.

 

Warranty:

All Runtal radiators are covered by a 5-Year Limited Warranty.

 

Manufacturer:

Subject to compliance with requirements, provide flat tube panel radiation as manufactured by Runtal North America, Inc.

 

OPTIONAL ITEMS WHICH MAY BE ADDED TO THE SPECIFICATION:

  1. Ribbed pipe cover trims, finished to match the radiators shall be provided with the radiation.
  2. The radiation manufacturer shall provide combination shutoff valve/union fitting of less than two inches in width for the supply and return to each panel radiator, to be field installed by others.
  3. Runtal-Flex connectors shall be used where appropriate to provide expansion compensation for the radiators.

Product Specifications (PDF)

BTUH/ft Ratings

Heating Capacity

Correction Factors

Flow Rates

How To Determine Flow Rates

The flow rate through a Runtal radiator (or series of radiators) is dependent on the length of the radiator (or combined length of the radiator series), and the design Entering Water Temperature (EWT) and the design Leaving Water Temperature (LWT).

The designer picks the design EWT and LWT. For example, he might pick 170°F as the EWT and 150°F as the LWT. The median point between these two temperatures is called the Average Water Temperature (AWT), and in this example the AWT is 160°F.

The Runtal Heating Capacity charts are based on the heating capacity per foot of radiator, based on the designer’s chosen AWT, and this heating capacity per foot is expressed in units of BTUH/FT @ a given AWT. The required flow rate (GPM) is figured as follows:

Flow Rate = (Heating Capacity/Foot X Radiator Length)

DT –LWT) X 500]

The (EWT – LWT) is commonly referred to as the “Delta T”, or “DT”.

Therefore, our Flow Rate formula becomes:

GPM = (BTUH/FT X FT of Radiator) DT (DT X 500)

As an example, let’s say our designer needs 445 BTUH/FT capacity, over a
10′-0″ span of wall, and has chosen the design water temperatures as EWT = 170°F, and LWT = 150°F. This means our AWT is 160°F. Looking in the Runtal type “R” radiator Heating Capacity chart, we see that an R-4 radiator gives us the required 445 BTUH/FT at 160°F AWT. Therefore, the required flow rate for the 10′-0″ long R-4 radiator is:

GPM = (445 BTUH/FT X 10FT) DT (20°F DT X 500) = 0.445 GPM

Note that there are various combinations of EWT and LWT that can result in the same AWT. In our example above, for instance, a 180°F EWT and a 140°F LWT result in the same 160°F AWT. With Runtal’s unique flattened water tube design, Delta T’s of up to 60°F are possible without concern that the flow rate is too low for heat transfer.

As for a maximum flow rate for Runtal radiators, we recommend no more that 1.5 GPM per water tube. For our R-4 example above, this would mean a maximum flow rate of 6 GPM for an opposite end piped radiator, or 3 GPM for a same end piped radiator. 

 

Piping Options

Pressure Drop: Opposite End

Pressure Ratings

Pressure ratings for the radiation shall be as follows:

STANDARD: Working pressure-56 PSI maximum, Test Pressure-74 PSI maximum
HIGH: Working pressure-128 PSI maximum, Test Pressure 184 PSI maximum

Detailed Specifications (PDF)

Mounting Systems

Wall Mounting

Finishes

The panel radiation shall be cleaned and phosphatized in preparation for the powder coat finish. The radiation is then finish painted with a gloss powder coat finish, for a total paint thickness of 2-3 mils (0.002” – 0.003”). The color shall be selected from Runtal’s ten Standard Colors; or Runtal Optional Colors shall be available at and additional cost.

Detailed Specifications (PDF)

Warranty

All Runtal radiators are covered by a 5-Year Limited Warranty.

Warranty (PDF)

Radiator Installation Instructions

  1. Radiators are boxed together in as few crates as possible. A box of brackets is included as a separate piece, and it is marked to denote brackets. Inside the crates, each panel is wrapped in foam sheeting. Saving this foam to re-wrap the panel once it is wall mounted will protect it from construction site damage.
  2. Each radiator is tagged with a label that indicates the project name, model type, color, connection code, bracket type & quantity and tag number. The tag number will usually designate a floor level and room number for easier placement on the job. Locate each radiator as required.
  3. Carefully place each radiator face down on a smooth level surface (e.g. floor or table). Distribute the K12 wall brackets for each radiator. The tag on the radiator indicates the quantity of brackets. Mount the brackets securely on wall studs, spacing them as evenly as possible at 2 to 4 feet apart, with a bracket at least 12 inches from each end of the panel. Allow a minimum of 3 inches below each panel radiator to facilitate cleaning and to assure proper output. For baseboard models, 2 inches or even 1 inch above the floor is permissible with little loss of heat output.
  4. RADIATORS WITH FINS (BACK SIDE OF PANEL)
    With the radiator face down, attach each K12 clip to the fins at the stud location. With the radiator still face down, thread the K45 offset bolts (5/16” carriage bolts) into the bottom threaded positions with a crescent wrench. Once the bolts have cleared the paint away, they should turn easily by hand. Attach the K12 bracket to the wall stud with 2 lag bolts. Hang the panel onto the brackets to determine if the K45 offset bolts are properly adjusted. Check that the panel is level.
  5. RADIATORS (NO FINS ON BACK SIDE OF PANEL)
    With the radiator face down, attach each K12 clip to the radiator’s perforated steel mounting channel at the K12 stud locations. With the radiator still face down, thread the K45 offset bolts (5/16” carriage bolts) into the bottom threaded positions with a crescent wrench. Once the bolts have cleared the paint away, they should turn easily by hand. Hang the panel onto the brackets to determine if the K45 offset bolts are properly adjusted. Check that the panel is level.
  6. Remove the radiator from the wall, and thread the supply and return fittings into the connections on the panel. The sealing tape or pipe dope used is the installer’s choice – make sure the connections are leak tight. One quarter of a turn past hand tight is usually sufficient. Use the foam wrap as a pad for the face of the panel while tightening up the fittings. Each radiator needs to be fitted with a 1/8” air vent prior to startup.
  7. FLOOR POST & PEDESTAL MOUNTED RADIATORS
    When using floor posts, each post must line up with a corresponding K45 offset bolt attached to the back side of the radiator. Using this spacing as a guide, securely fasten each floor post to the floor, using appropriate fasteners. The K12 wall bracket is attached to the floor post, and the K12 clip to the radiator, as described in step #4. The nut and bolt used to attach the K12 bracket to the floor post is to be supplied by others.
    For pedestal mounting, the pedestals should be arranged so that the end pedestals sit within 12 inches of each end of the radiator, with the remainder spaced evenly along the radiator’s length. Each pedestal should be securely fastened to the floor using appropriate fasteners. Radiators sit on the pedestals, with the “fingers” of the pedestals sticking up between the fins to provide stability.
  8. Radiators expand a maximum of 0.016 inch per linear foot of length if heated to 215°F. Piping attached to the radiator must provide the necessary expansion compensation.
  9. Once the radiators are installed, the system can be tested to 50 psi. DO NOT OVER-PRESSURIZE THE RADIATORS as permanent damage may be done.
    • Standard Pressure Panels: Maximum 56 psi
    • High Pressure Panels: Maximum 128 psi
    • When the system has been shown to hold 50 psi maximum air, the piping and radiators can be filled with water. As water fills the system and radiators, air is forced to the vent fittings. Vent as much air as possible before turning on the circulating pump(s).
  10. When the system is filled, operate the circulator(s) to force the remaining air to the high points of the system. With the system pressurized, turn off the circulator(s) to vent the panels. Each radiator should be individually bled of air. Once cold venting has been completed, heat the system to design temperature and repeat the venting procedure as many times as necessary to remove all air from the system.

Radiator Installation Instructions (PDF)

Operation & Maintenance

  1. Radiators are manufactured in the USA of cold rolled low carbon steel and should be used only in closed closed hydronic systems to assure no corrosion of any system components.
  2. Proper radiator operation depends on adequate flow of water to the panel, which can only be accomplished when all the system air has been fully vented from the panels.
  3. Radiators should each be vented, with the system pressurized but in a static state (pumps off). Venting may need to be done periodically to assure a closed system.
  4. DO NOT OVER-PRESSURIZE RADIATORS:
    Most radiators are standard pressure construction. Standard pressure radiators should be tested with NO MORE THAN 50 PSI.
  5. Radiator Operating Pressure Ratings:
    Standard Pressure – 56 psi max (Tested at 74 psi)
    High Pressure – 128 psi max (Tested at 184 psi)
  6. Radiators expand a maximum of 0.016 inch per linear foot of length if heated to 215°F. Piping attached to the radiator must provide the necessary expansion compensation.
  7. Flexible piping and elbowed piping are two simple ways to provide the 1/8 inch to 1/2 inch (typical) of flexibility required in expansion situations (usually series piping).
  8. Runtal Radiators require less flow rate than other hydronic heating products. If flow noise is apparent, balance the system until the noise is reduced.
  9. For a delta T of 20°F. (T supply minus T return), divide the total Btu/hr capacity of the loop by 10,000. This gives the Flow Rate in gallons per minute (GPM)
  10. Many levels of control are available today for hydronic systems. Runtal Radiators will provide nice, even heating whether operated by a simple thermostat to baseboard loop system, or an advanced boiler reset controller with motorized mixing valves, constant circulation and 2-pipe distribution.

Operation & Maintenance (PDF)

Radiator Maintenance

  1. Hydronic system maintenance should include routine checks for piping leaks (usually indicated by frequent makeup water), and a yearly diagnosis of the system water pH to evaluate its corrosive potential.

  2. Internal radiator maintenance depends entirely on the system water makeup and proper venting. Hydronic system additives are available to passivate and protect against freezing. These additives will not significantly reduce the output of Runtal Radiators.

  3. External radiator maintenance consists of keeping the surfaces clean, and any paint nicks or deep scratches painted with touch-up to prevent any surface rust.

  4. Radiators can be painted after sanding with fine grit paper to dull the high gloss and by wiping with solvent or a tack rag. Use only oil-based enamel paint (alkyd, acrylic, urethane, epoxy) – do not use latex or lacquer paint. Use urethane or epoxy enamel for radiators located in harsh environments. Spray the paint to achieve an even coating, and let dry completely before heating the radiator.

 

Operation & Maintenance (PDF)