issue: March 2008 APPLIANCE Magazine
The Heating Capacity of Room Air Conditioners
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by Wasaku Ishida, Japan Correspondent and President, JARN (Japan Air Conditioning, Heating & Refrigeration News)
As the heating capacity of heat pump air-conditioners has improved in recent years, producers have endeavored to expand the scope of application of their product to include more space heating. In fact, even in cold districts in Northern Japan, heat pump A/Cs are beginning to draw attention as combustion-free heaters.
Manufacturers are attempting to increase the heating capacity of their room air-conditioners (RACs) and accelerate sales by promoting the powerful heating capacity of these appliances. Daikin and Mitsubishi Electric Corp. (Melco) have even developed RAC-based products capable of supplying hot water to a floor heating system.
New single-family homes and premium apartment homes are being constructed with higher levels of thermal insulation and increased air-tightness, and have significantly lower heat loss than homes in the past. In many of these homes, it is possible to handle the heating load with larger-capacity heat pump air-conditioners. The units fit well into Japan’s all-electric-home trend, and the lack of an open flame makes them popular with consumers concerned with safety.
The heat pump water heater, called Eco-Cute in Japan, uses a natural CO2 refrigerant and is also finding its way rapidly into all-electric homes. Large-capacity Eco-Cute units supplying hot water to floor heating are available from many manufacturers. Melco released the Zubadan Kirigamine series, promoting its advanced heating performance. New models can send hot air down to foot level and have a “Body-Sensing Move-Eye” to detect floor and wall temperatures as well as the movement of room occupants, then controls the delivery of warm air where needed.
Hitachi has also released floor-standing RACs with a heat pump that can deliver warm air at foot level. The units can utilize the exhaust air vent previously used in the home for a kerosene space heater. They enable operation via an indoor unit control panel. Hitachi model RACs for 2008 have 40% higher heating capacity than models from 11 years ago.
Matsushita, in its third season of developing RACs with heating ability, launched the Airstream Robot (Air-Robo) X series in November 2007. The unit’s body sensor locates the position of users in the room and responds to offer comfort conditioning for each user.
For the last three years, even Hokkaido, the northernmost island in Japan, has been visited by intense heat waves that have driven up RAC demand each year. Still, the rate of penetration into ordinary homes remains at only 15–16% across the whole of Hokkaido. Producers believe that, if they can provide more-powerful space heating in the units, RAC demand will increase even more in the vicinity.
In fact, there may never be a better time to promote new heating options on the island, where undependable gas and oil suppliers in recent years have forced many consumers to get rid of their combustion-type heating. Furthermore, the number of all-electric homes has increased, along with the trend to use higher levels of thermal insulation and increase home air-tightness. Hokkaido’s consumers are gradually coming to a higher degree of awareness of RACs and their heating performance.
On the other hand, the people of Hokkaido have a strong preference for a living style in which their doors throughout several rooms are left open—not conducive for the heating capacities of RAC heat pumps.
Nevertheless, said the head of Matsushita Hokkaido headquarters, “We have steadily increased demand for our products.”