Back to 2007 listAnnouncing Release of Hot-Eco VRV, High-Efficiency Office Building Multi Heater/Air Conditioner for Cold Climates
- Comfortable heating with big energy savings even in cold areas -
February 21, 2007
Daikin Industries, Ltd.
Hokkaido Electric Power Co., Ltd.
Tohoku Electric Power Co., Inc.
Chubu Electric Power Co., Inc.
Hokuriku Electric Power Company
The Chugoku Electric Power Co., Inc.
Daikin Industries, Ltd., Hokkaido Electric Power Co., Ltd., Tohoku Electric Power Co., Inc., Chubu Electric Power Co., Inc., Hokuriku Electric Power Company and the Chugoku Electric Power Co., Inc. have conducted proving tests of the Hot-Eco VRV, a high-efficiency office building Multi heater/air conditioner for cold climates. The device provides comfortable heating with big energy savings even in cold areas like Hokkaido and Akita, where it was tested. Having confirmed target performance for the device, Daikin Industries will launch sales this August.
The desire to save energy and lower the risk of global warming has encouraged the development of high-efficiency heater/air conditioners in recent year. Users in cold climates have particularly sought heating systems that work efficiently when the temperature outside is low. Although existing heat pumps are efficient, their heating capacity may decline when the outdoor temperature is cold, making the interior less comfortable.
The recently developed "Hot-Eco VRV" has a new two-stage compression system(*1) that greatly boosts heating efficiency even during cold seasons. The device adds to interior comfort while the unit is heating with its vastly improved heating capacity, its ability to blow warm air into the room faster and its lesser temperature drop from defrosting.
Characteristics of the "Hot-Eco VRV" are as below.
(1) Industry-leading energy performance
The new two-stage compression system greatly improves the device's COP(*2) when the outside air is cold. Its 14-horsepower outdoor unit has achieved an industry-leading heating system COP(*3) of 3.18 when the outside air temperature is -10°C. As a result, the device offers a maximum of 22% energy savings as compared to the old model(*4), with CO2 emissions similarly reduced by a maximum of 22%(*5).
(2) Cuts running costs by up to 27%
The improved COP during heating results in a maximum reduction of running costs of 27%(*6).
(3) Greater comfort when the temperature outside is low
The two-stage compression system improves device function as follows.
- • Heating capacity when the outside air temperature is -10°C is 30% higher(*7).
- • The time between device startup and the flow of warm air is 60% shorter at an outside air temperature of -10°C(*8), so the interior warms up faster.
- • The time taken to defrost, which can cause the room temperature to dip slightly, has been reduced by up to 47%(*9), greatly enhancing the ability of the unit to maintain the indoor temperature.
The six companies will continue actively developing energy saving devices to conserve energy and prevent global warming while helping customers to lower their energy costs and increase comfort.
(*1) Two-stage compression system
Two compressors are connected in a series so that air is compressed incrementally.
The new device has an intermediate cooler and bypass circuit between the two compressors, enabling each one to operate incrementally and efficiently. The system therefore heats efficiently even at low outside air temperatures.
(*2) COP
The air conditioning capacity divided by energy consumption.
The higher the value, the greater the energy performance.
(*3) Heating system COP
Indicates the heater COP when the indoor unit is 100% connected to the outdoor unit.
Heating system COP = heating capacity / (outdoor unit heating energy consumption + indoor unit heating energy consumption)
The value indicated is for a case where there is an outdoor unit of 14 horsepower, and two indoor units each of 3.2 horsepower (P90) and 4 horsepower (P112) (ceiling-embedded cassette, round flow type) are connected.
(*4) Maximum of 22% energy savings as compared to the old model
Value based on calculation of power consumption (units: MWh/year)
| Area (typical city) |
Daikin Industries old model (A) | "Hot-Eco VRV" (B) | (A-B) / A × 100 |
| Hokkaido (Sapporo) |
105 | 82 | 22% |
| Tohoku (Aomori) |
87 | 77 | 12% |
| Chubu (Nagano) |
88 | 80 | 9% |
| Hokuriku (Toyama) |
84 | 81 | 4% |
| Chugoku (Tsuyama) |
85 | 82 | 4% |
(*5) CO2 emissions reduced by a maximum of 22%
Value based on calculation of annual CO2 emissions (units: kg-CO2/year)
| Area (typical city) |
Daikin Industries old model (A) | "Hot-Eco VRV" (B) | (A-B) / A × 100 |
| Hokkaido (Sapporo) |
44,625 | 34,850 | 22% |
| Tohoku (Aomori) |
36,975 | 32,725 | 12% |
| Chubu (Nagano) |
37,400 | 34,000 | 9% |
| Hokuriku (Toyama) |
35,700 | 34,425 | 4% |
| Chugoku (Tsuyama) |
36,125 | 34,850 | 4% |
(*6) Maximum reduction of running costs of 27%
Value based on calculation of annual running cost (units: thousands of yen/year)
| Area (typical city) |
Daikin Industries old model (A) | "Hot-Eco VRV" (B) | (A-B) / A × 100 |
| Hokkaido (Sapporo) |
3,594 | 2,624 | 27% |
| Tohoku (Aomori) |
2,566 | 2,078 | 19% |
| Chubu (Nagano) |
2,604 | 2,089 | 20% |
| Hokuriku (Toyama) |
2,052 | 2,027 | 1% |
| Chugoku (Tsuyama) |
2,343 | 2,144 | 8% |
< Assumptions for Notes 4, 5, 6 >
| Building size | : | 3,000m2 |
| Heated/air conditioned surface area | : | 80% |
| Floors | : | Five, no basement |
| Construction | : | Reinforced concrete |
| Building use | : | office building |
| Heated/air conditioned hours | : | 8:00 AM - 8:00 PM (12 hours) |
| CO2 emissions base unit | : | 0.425kg-CO2/kWh |
(source: FY2005 results as found in Electricity Power Companies' Environmental Action Plan FY2006, Federation of Electric Power Companies of Japan)
*Weather conditions, heating load, etc. vary in the five areas.
(*7) Heating capacity when the outside air temperature is -10°C is 30% higher
As compared to Daikin Industries old model (14-horsepower outdoor unit).
(*8) The time until the flow of warm air is 60% shorter
Comparison of the time between device startup and the flow of warm air (i.e. the time until the indoor unit heat exchanger reaches 40°C) is from measurement data when the outdoor air temperature was about -10°C in Asahikawa.
(*9) Defrosting time reduced by up to 47%
At low outdoor temperatures, frost forms on the outdoor unit, causing heating capacity to decline. This makes it necessary to melt the frost periodically, using indoor heat.
The 47% savings in defrosting time is based on a comparison of the time taken as the indoor unit heat exchanger drops below 40°C, the defrosting cycle ends and the heat exchanger returns to 40°C.
The time savings is 57% when comparing only the time of reverse cycling (i.e. time to switch the four-way valve) in order to defrost.
This is from measurement data when the outdoor air temperature was about -10°C in Asahikawa.
[Product inquiries]
Product Planning Department, Air Conditioning Division, Daikin Industries, Ltd.
TEL (06) 6373-4309
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