14
Gas Water Heaters
Target Scope
Gas water heaters, except the following:
1) ones which are not the objects of JIS S 2109 (2019) or JIS S 2112 (2019),
2) ones for business use,
3) ones which are not using City Gas 13A group for fuel,
4) ones which are Gas instant water heaters that are natural ventilation type for ventilation and are not unvented type for exhaust,
5) ones which fall under any the following, or
- ones which do not have water supply functions,
- ones which are natural ventilation type for ventilation,
- ones which are natural circulation type for circulation,
- ones whose structure are using only indoors to install,
6) ones which are used for only space heating.
Energy Consumption Efficiency
①Each subsequent fiscal year (until FY2024)
[Gas instant water heaters and bathtub gas heaters (with no hot water supply function)]
●Energy consumption efficiency shall be heat efficiency (%) measured as stipulated in JIS S 2109 (2019).
[Gas water heaters for space heating (with no hot water supply function)]
●Energy consumption efficiency shall be heat efficiency (%) when the water temperature difference between outward flow and inward flow in a hot water circulation becomes the specified level.
[Bathtub gas water heaters (with hot water supply functions)]
●Energy consumption efficiency shall be the weighted average value obtained by a 1:3.3 ratio (1 for bath section heat efficiency, 3.3 for hot water supply section heat efficiency).
[Gas water heaters for space heating (with hot water supply functions)]
●Energy consumption efficiency shall be the weighted average value obtained by a 1:3 ratio (1 for space heating section heat efficiency, 3 for hot water supply section heat efficiency).
②FY2025 and each subsequent fiscal year
[Gas instant water heaters and bathtub gas heaters]
●Energy consumption efficiency shall be heat efficiency (%) measured as stipulated in JIS S 2075 (2011)
[Gas water heaters for space heating]
●Energy consumption efficiency shall be the weighted average value obtained by a 1:3 ratio (1 for space heating section heat efficiency, 3 for hot water supply section heat efficiency).
Categories & Target Standard Values
①Each subsequent fiscal year (until FY2024)
In the target fiscal year and each subsequent fiscal year, for each category, the weighted average value obtained by weighting energy consumption efficiency with shipment volume shall not be below the target standard value.
| Category | [Target standard value] Standard energy consumption efficiency | ||||
|---|---|---|---|---|---|
| Gas water heater type | Ventilation type | Circulation type | Exhaust type | Category name | |
| Gas instant water heaters | Natural ventilation type | ― | Unvented type | A | 83.5 |
| Other than unvented types | B | 78.0 | |||
| Forced ventilation type | ― | Other than outdoor types | C | 80.0 | |
| Outdoor type | D | 82.0 | |||
| Bath tub gas water heaters (with no hot water supply functions) | Natural ventilation type | Natural circulation type | Vented type or direct vent type (the height where the air supply and exhaust part penetrates external wall is as high as vented types) | E | 75.5 |
| Direct vent type (other than types of the height where the air supply and exhaust part penetrates external wall is as high as vented types) | F | 71.0 | |||
| Outdoor type | G | 76.4 | |||
| Forced ventilation type | Natural circulation type | ― | H | 70.8 | |
| Forced circulation type | ― | I | 77.0 | ||
| Bath tub gas water heaters (with hot water supply functions) | Natural ventilation type | Natural circulation type | Vented type or direct vent type (the height where the air supply and exhaust part penetrates external wall is as high as vented types) | J | 78.0 |
| Direct vent type (other than types of the height where the air supply and exhaust part penetrates external wall is as high as vented types) | K | 77.0 | |||
| Outdoor type | L | 78.9 | |||
| Forced ventilation type | Natural circulation type | ― | M | 76.1 | |
| Forced circulation type | Other than outdoor types | N | 78.8 | ||
| Outdoor type | O | 80.4 | |||
| Gas water heater for space heating (with no hot water supply functions) | ― | ― | ― | P | 83.4 |
| Gas water heater for space heating (with hot water supply functions) | ― | ― | ― | Q | 83.0 |
②FY2025 and each subsequent fiscal year
In the target fiscal year and each subsequent fiscal year, for each category, the weighted average value obtained by weighting energy consumption efficiency with shipment volume shall not be below the target standard value.
| Category | [Target standard value] Standard energy consumption efficiency |
||
|---|---|---|---|
| Category name | Purpose | Ventilation type | |
| Ⅰ | Gas instant water heaters | Natural ventilation type | 77.50% |
| Ⅱ | Forced ventilation type | 84.37%×αⅡi | |
| Ⅲ | Bath tub gas water heaters | 87.21%×αⅢi | |
| Ⅳ | Gas water heater for space heating | 90.32% | |
| Structure type | αⅡi |
|
|---|---|---|
| Structure Name |
Structure | |
| Ⅱ-1 | Through-the-wall type | 0.9998 |
| Ⅱ-2 | Wall built-in type | 0.9869 |
| Ⅱ-3 | Forced flue type | 0.9900 |
| Ⅱ-4 | Forced exhaust type (limited to conventional type) | 0.9661 |
| Ⅱ-5 | Integrated with cooking range ventilator cover (limited to conventional type) | 0.8415 |
| Ⅱ-6 | Other | 1.0000 |
| Structure type | αⅢi |
|
|---|---|---|
| Structure name | Structure | |
| Ⅲ-1 | Through-the-wall type | 0.9839 |
| Ⅲ-2 | Wall built-in type (limited to conventional type) |
0.9576 |
| Ⅲ-3 | Other | 1.0000 |
【Judgment criteria exceptions】
①The manufacturers of appliances are required to keep the harmonic mean of the energy consumption efficiency of appliances shipped for each fiscal year starting from the targeted fiscal year, weighted with shipment volume by category, at the same level or higher than the harmonic mean of the standard energy consumption efficiency weighted with shipment volume by category. Also as an exception, evaluation through average thermal efficiency by company is adopted.
②At the same time, it was made possible to add hybrid water heaters to the calculation of the value of average thermal efficiency by company.
ηAH＝[{Σ365j=1ρw×Cp×Vw,j×(Ｔw2－Ｔwl,j)/1000}×100]/{Σ365h=1(EDHPele,j＋EDTANKele,j)×Cprim＋Σ365h=1QDHgas,j}
In this formula, ηAH、ρw、Cp、Vw,j、Ｔw2、Ｔwl,j、EDHPele,j、EDTANKele,j、Cprim and QDHgas,j represent the following things.
ηAH：energy consumption efficiency（Unit %）
ρw：water density（1000 kg/m3）
Cp：constant pressure specific heat of water（4.186 KJ/kg・K）
Vw,j：daily cumulative hot water supply on a j day（Unit Littler/day）
Ｔw2：hot water temperature（40 ℃）
Ｔwl,j：hot water temperature on a j day（Unit ℃）
EDHPele,j：eatimated daily integrated heat pump power consumption on a j day（Unit kWh/day）
EDTANKele,j：estimated daily cumulative hot water storage unit power consumption on a j day（Unit kWh/day）
Cprim：primary energy conversion factor of electricity（9.76 MJ/kWh）
QDHgas,j：estimated daily cumulative hot water supply gas consumption on a j day（Unit MJ/year）
Target Fiscal Year
[Gas instant water heaters and bathtub gas heaters]
●FY2006 and each subsequent fiscal year (until FY2024)
FY2025 and each subsequent fiscal year
[Gas water heaters for space heating]
●FY2008 and each subsequent fiscal year (until FY2024)
FY2025 and each subsequent fiscal year
Energy Efficiency Improvement
●Energy consumption efficiency was improved by about 5.2% in the target fiscal year (FY2025).
Display Items
●Product name and type
●Category name
●Structure name(limited to cases of category Ⅱ or category Ⅲ)
●Energy consumption efficiency
●Name of manufacturer, etc.
Display Location
●Display items shall be presented at locations where they can be readily noticed in catalogs showing performance indications and on product bodies.
Requirement for Recommendations and Orders
Manufacturers or importers whose annual manufacturing volume or importing volume (limited to shipment to the domestic market) is 3,000 units or more may be subject to recommendations and orders.
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