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Product Introduction
Guide to Design & Installation


SUNJOY PLUS, the heating system that is augmented only with benefits customers have always wanted on top of all the benefits of SUNJOY, 
which delivers the same warm feeling of the sunlight. SUNJOY PLUS is opening a new chapter of the ceiling-mount radiant heating system.

Estimation of the Capacity

Simplified Method to Estimate the Required Capacity (Korea oriented Method)

Q: Volume of the Target Space(m³)

T : Initial Temperature Before Heating(℃)

T : T₂: Target Temperature(℃)

△T : Temperature Difference between the Initial Temperature and the Target Temperature(T-T)

F : Insulation Factor

Insulation Status Insulation Factor[F] Initial Temperature Before Heating
Excellent insulation (Sauna) 350 22℃
Very good insulation (Multi-family residential buildings) 300 19℃
Good insulation (Single-family houses) 250 16℃
Moderate insulation (South-facing offices) 200 13℃
Fair insulation (North-facing offices) 150 10℃
Poor insulation 100 7℃
Almost No Insulation 75 4℃

Outdoor air temperature is assumed to be 10℃.

Once the required capacity is estimated, the models of the panels and their numbers can be determined based on that.

Samples for the Estimation of the Capacity

(m²) (squre meter)
Initial Temp[T]
Target Temp[T]
Temp. Difference
Insulation Factor
Applicable Panels
Public bathrooms
(Freeze protection)
15.0 4.5
2.4 36 5 13 8 250 1,152 S
Residential bathrooms
5.0 1.5
2.4 12 15 25 10 300 396 [SR-4D]*1
Small-size offices
13.2 4.0
2.4 32 15 25 10 200 1,584 [SR-8D]*2
Patient rooms in hospitals
26.5 8.0
2.4 64 12 25 13 250 3,307 [SR-8D]*4
Studio apartments
39.5 12.0
2.4 95 15 25 10 250 3,792 [SR-9D]*4
Public bathrooms
(Freeze protection)
16.4 5
2.4 39 6 13 7 150 1,837








Small-size offices
13.3 4
2.4 32 14 25 11 200 1,756 [SM-7]*2
High-ceiling stores
29.8 9
3 89 13 24 11 250 3,934 [SM-10]*4
Pension (room)
15 4.5
2.4 36 17 25 8 250 1,152 [SM-5]*2

Location shall be determined considering the interference from finished surface of ceiling such as ventilation facility, lights or partitions.

Heater shall be installed with 600mm distance from outer wall, and between heating plates the distance shall be twice than this distance. Various size are available so that it can be installed any space.

System Design

Installation Diagrams

Thermostats: Types and Circuit Diagrams

Cetral controll type Thermostat system.


① Remove "false ceiling" according to product rear part size

②-1 Connecting the lead wire to the Output power wire

②-2 Close-up of connection part

②-3 Termination of connection with insulation tape

1. Check the heat insulation of the room to be installed, clean the ceiling surface, mark the installation site, remove the ceiling tile according to the size of the product to be installed<Pic >, and connect the power cord do. <Pic >

③ Close-up of M bar

④ Fix the heater to M bar

⑤ Screwed to ceiling frame

⑥ Attach closure caps on frame holes

2. Fixed to the ceiling frame (M-BAR or T-BAR) through the frame hole of the product with the screws provided as accessories <Pic ><Pic > and finished by putting the Closure caps into the product frame hole where the screw is located, <Pic >

⑦ Rear side of Themperature controller

⑧ Wire connection diagram

3. After preparing the power input line (Distribution board → Temperature controller), connect the power input line to the temperature controller INPUT and the Output power line connected to the product to the OUTPUT using the terminal. (When using external temperature sensor, connect temperature sensor wire) <Pic ⑧>

⑨-1 A case of Installing a Themperature controller on a wall

⑨-2 A case of Installing a Themperature controller on a ceiling

⑩ Check of Themperature controller's operation

⑪ Check of Heating panel's operation