Commercial Storage Gas

DIMENSIONS AND TECHNICAL DATA TABLE - INDOOR MODEL
Storage Capacity		litres	275
Dimensions
	A	mm	1895
	B	mm	640
	C	mm	780
	D	mm	760
	E	mm	700
	F	mm	340
	G	mm	1695
	H	degrees	36
	K	mm	722
	L	mm	320
	M	mm	200
	P	mm	-
Weight - Empty		kg	187
Inlet/Outlet Connections (BSPF)			RP1¼/32
Gas Connection (BSPF)			RP¾/20
T&PR Valve Connection (BSPF)			RP¾/20
T&PR Valve Setting		kPa	1000
Expansion Control Valve (ECV)10 Setting		kPa	850
without ECV10 fitted		kPa	800
with ECV10 fitted		kPa	680
Max. Thermostat Setting		°C	82
Factory Thermostat Setting		°C	70
Min. Thermostat Setting		°C	60
Manifold - Min. Centre to Centre		mm	890
Electrical Connection			2m 10A Plug and Lead
Electrical Rating 240V 50Hz			150 Watts
			0.65 Amps

PERFORMANCE DATA
No. of Units in Parallel	Initial Storage Capacity	Thermal Input	Litres hot water at 50°C rise over peak period (based on natural gas)
	(Litres)	(MJ/h)	1 hour	2 hours	3 hours	4 hours	6 hours	8 hours
1	275	200	970	1710	2460	3200	4690	6180
2	550	400	1930	3420	4910	6400	9380	12370
3	825	600	2900	5130	7370	9600	14080	18550
4	1100	800	3860	6840	9820	12810	18770	24730
5	1375	1000	4830	8550	12280	16010	23460	30910
6	1650	1200	5790	10260	14740	19210	28150	37100
No. of Units in Parallel	Initial Storage Capacity	Thermal Input	Litres hot water at 65°C rise over peak period (based on natural gas)
	(Litres)	(MJ/h)	1 hour	2 hours	3 hours	4 hours	6 hours	8 hours
1	275	200	790	1370	1940	2510	3660	4810
2	550	400	1590	2730	3880	5030	7320	9610
3	825	600	2380	4100	5820	7540	10980	14420
4	1100	800	3170	5470	7760	10050	14640	19230
5	1375	1000	3970	6830	9700	12570	18300	24030
6	1650	1200	4760	8200	11640	15080	21960	28840

Operations at temperatures above 80°C

Rheem commercial gas models 621 265, 631 265, 621 275, 631 275 are designed to operate at temperatures up to 82°C for sanitising and other applications.

Where the water supplied by the water heater is required consistently at any temperature above 80°C, we strongly recommend you use a pumped recirculation system. (Please refer to the Equa-Flow® section.)

Gas pipe supply

The gas supply piping should be sized in accordance with AS/NZS5601.1

The gas supply pipe must be sized so that the minimum gas pressure is available at the inlet to each water heater when all appliances are operating at maximum gas consumption.

The minimum gas pressures are 1.13 kPa for natural and SNG, 2.75 kPa for propane and butane and 0.75 kPa for town gas and TLP.

TECHNICAL GAS PERFORMANCE DETAILS
Gas Type		Nat/SNG	Propane	Butane
Thermal Input	MJ/h	200	190	160
Output	kW	43.3	41.2	34.7
Min. Gas Supply Pressure	kPa	1.13	2.75	2.75
Test Point Pressure	kPa	0.90	2.65	2.65
Max. Gas Supply Pressure	kPa	3.5	3.5	3.5
Litres Recovery Per Hour at Rise of	20°C	1870	1780	1500
	30°C	1250	1190	1000
	40°C	940	890	750
	50°C	750	710	600
	60°C	630	600	500
	65°C	580	550	460
	70°C	540	510	430
	75°C	500	480	400

Approximate daily energy consumption

These daily gas consumption figures are approximate. They’re based on:

• A daily usage of hot water per water heater in litres, at 50°C rise
• Using natural gas, but they can be used with reasonable accuracy for other gas types
• Mains pressure supply systems only

The figures do not allow for pipe heat losses. An additional allowance must be made for large manifold systems and installations designed with a circulated flow and return system.

Use the table to calculate

• The approximate energy cost for a particular installation
• The average daily hot water consumption when the energy consumption is known

APPROXIMATE DAILY ENERGY CONSUMPTION
Daily Hot Water Usage @ 50°C Temp Rise	Energy Content of Hot Water	Approximate Energy Used Per Day Natural Gas
(Litres)	(MJ)	(MJ)
0	0	26.1
50	10.5	39.6
100	20.9	53.1
150	31.4	66.5
200	41.9	80.0
250	52.3	93.5
300	62.8	106.9
350	73.3	120.4
400	83.7	133.9
450	94.2	147.3
500	104.7	160.8
600	125.6	187.8
700	146.5	214..7
800	167.4	241.6
900	188.4	268.6
1000	209.3	295.5
1250	261.6	362.8
1500	314	430.2
1750	366.3	497.5
2000	418.6	564.9
2500	523.3	699.6
3000	627.9	834.2
3500	732.6	968.9
4000	837.2	1103.6
5000	1046.5	1373.0

To convert to kg of Propane, divide MJ by 49.5. To convert to litres of Propane, divide MJ by 25.3.

Ventilation for indoor gas water heaters

It’s a requirement of AS/NZS5601.1 that indoor gas water heaters (non room sealed) are installed in a location with adequate ventilation.

Two permanent openings are required into the room housing the water heaters.

The distance from the top of the upper opening to the ceiling and from the bottom of the lower opening to the floor, cannot each exceed 5% of the room height.

The two openings can be combined, as long as the top and bottom of the opening are within the 5% distance requirement.

The minimum vertical dimension of any free ventilation opening is 6mm.

The minimum free ventilation area of each opening required for each Rheem commercial gas water heater installed is shown in the table.

Please refer to AS/NZS5601.1 for full details of the requirements.

Notes

1. Although a room sealed water heater installation draws the air required for combustion from outside, ventilation may be necessary to prevent a rise in the ambient temperature in the room.
2. In plant rooms, wherever possible more than one wall should be used to provide ventilation. This allows a flow of air across the room and helps prevent excessive temperatures in the room.
3. In rooms other than plant rooms, ventilation is required if the total thermal input of the water heaters exceeds 3 MJ/h per cubic metre of room volume.
4. AS/NZS5601.1 should be consulted for further requirements when ventilating through adjacent rooms to the water heater installation.

VENTILATION REQUIREMENTS
	Natural Ventilation (Area of Each Opening Per Water Heater)				Mechanical Ventilation (Per Water Heater)
	Location of Water Heater
	Plant Room		Non Plant Room		Low Level	High Level
Thermal Input	Direct to Outside	via Adjacent Room	Direct to Outside	via Adjacent Room	Mechanical Air Supply	Mechanical Exhaust	Natural Exhaust
MJ/h	(cm2)	(cm2)	(cm2)	(cm2)	(L/s)	(L/s)	(cm2)
200	300	600	600	1200	100	29	300

Natural air supply with a mechanical exhaust is not permitted.

Power fluing

You can either install an individual Rheem gas model or a bank of multiple 621 265, 621 275 models with a power flue.

It’s essential to prove the flue system operates correctly before the main burner is allowed to operate.

How do you achieve this? A self proving relay interconnected with either a vane switch or pressure differential switch will prove both air flow and functionality of the control circuit before ignition of the main burner.

Please refer to AS/NZS5601.1 for full details of what’s required.

For multiple installations, the operating principle is the same as for a single water heater.

Any water heater can switch on the fan, and the burners can only come on when the sail switch is closed.

Intermittent PowerFlue Fan Control – Multiple Water Heater Rheem 621 Series & Raypak Type B Series.

Power Flue and Remote control

Rheem commercial models 621 265, 631 265, 621 275, 631 275 may be controlled by a remote device such as a time clock, remote isolating switch, pressure switch or sail switch. Additionally, Rheem can assist with Power Flue design solutions for Rheem and Raypak® commercial gas water heaters. For further details please contact your local Rheem technical advisory service.

Fluing: indoor gas water heaters

Rheem indoor gas water heaters are designed for connection to a flue system in accordance with the requirements of AS/NZS5601.1.

Manifolded water heaters can either be flued individually or connected to a common flue. The design of the flue must comply with Appendix H of the Standard.

AS/NZS5601.1 states the vertical rise directly out of the water heater must be the maximum possible height before any change in direction.

Also, the total length of the lateral (horizontal) section must be as short as possible, not exceeding 50% of the total flue height of the system.

The table and diagram below are extracted from the Flue Tables in AS/NZS5601.1 and are meant as a quick guide only. Any variations should be referenced from AS/NZS5601.1.

Appropriate authorities should be consulted before any work is commenced on flues other than single appliance flues.

Multiple Manifold Flue System

FLUE SIZING FOR GAS WATER HEATERS
		1		2		4		6		8
	Total Flue Height	Max. Lateral	Flue Dia	Max. Manifold	Flue Dia	Max. Manifold	Flue Dia	Max. Manifold	Flue Dia	Max. Manifold	Flue Dia
	(H)			Length (A)		Length (A)		Length (A)		Length (A)
Model	(m)	(m)	(mm)	(m)	(mm)	(m)	(mm)	(m)	(mm)	(m)	(mm)
621 275	2	1	175	1	250	-	-	-	-	-	-
200 MJ/h	3	1.5	175	1.5	250	-	-	-	-	-	-
	6	3	150	3	200	3	300	-	-	-	-
	12	6	150	6	200	6	250	6	300	-	-
	24	7.6	150	12	175	12	250	12	300	12	300

Notes:

• The table is based on a natural draft system with an insulated type flue or a flue installed indoors
• The table is extracted from the Flue Tables in AS/NZS5601.1 and is meant as a quick guide only. Any variations should be referenced from AS/NZS5601.1