Heat pumps are gaining popularity because of their environmental credentials, writes Graham Wright of Sanyo, and air-to-water CO2 units will take the market by storm
With climate change causing increasingly warmer winters and hotter summers, and the rise of renewable technologies, BSRIA data suggests that demand for traditional heating products will slow down.
This trend is leading to product diversification in the climate control sector.

To answer environmental concerns, the hvac industry has been working hard to improve the efficiency of traditional climate control as well as moving to alternative solutions such as heat pump
systems.

As a result, air conditioning companies have adopted the energy-efficient two-way heat pump for almost all applications. This versatile technology has allowed many manufacturers to bring air-to-water or ground-source-to-water heat pumps into the heating market, providing low-temperature heated water for underfloor heating and sanitary hot water.

But the emergence of CO2 air-to-water heat pumps, such as Sanyo's CO2 Eco water heater, has resulted in the hvac industry taking another technological leap
forward.

Set to overtake sales in ground source heat pumps in Europe, the CO2 air-to-water heat pump originally derives from Japan where it was introduced in 2001 taking the market by storm.

Highly efficient

New to the UK, this type of unit is particularly attractive because of its high coefficient of performance (COP), high water temperatures and environmental refrigerant. For instance, Sanyo's CO2 Eco water heater can generate hot water up to 60˚C at a COP of 3.75, making it highly efficient when compared with electric heaters which generally have a COP rating of 1.

Meanwhile, for refrigerant, CO2 air-to-water heat pumps, such as the CO2 Eco, use heat energy derived from compressed CO2 gas, a non-toxic natural refrigerant which is less harmful to the environment than other refrigerants.

CO2 has an ozone-destruction potential of 0 and a global warming potential of 1. This offers a more environmentally friendly heating solution which is in line with Sanyo's overall Gaia-based, green philosophy, the company says.

According to Sanyo, the CO2 air-to-water heat pumps also have a rugged design which enables them to work in the toughest of environments. For instance, the CO2 Eco will operate continuously at low ambient conditions, in temperatures as low as -20°C, while still maintaining its performance at no less than 4kW.

In comparison, heat pumps that use HCFC or HFC refrigerant, can generally only withstand ambient temperatures down to around -10°C. Electric heaters are then required for operation in temperatures below this level, which results in a significant drop in overall unit efficiency.
Central to the CO2 Eco's performance is its rotary two-stage compression system, developed by Sanyo. According to the company, the technology represents a world first in compressor design; is resistant to high working pressure differentials; has high-reliability through load dispersion; and suffers lower leakage loss, as well as low vibration and noise levels during operation (45dBA).

Despite CO2 water heaters offering an alternative to traditional systems, they are based on proven heat pump technology, which is available worldwide. The units also have advantages over ground source heat pumps, which offer efficient systems but require higher initial investment due to installation which can require planning permission. In contrast, CO2 water heaters boast high system efficiency, low running costs but also low installation costs at the same scale as a room air conditioner's.

Sanyo says its CO2 Eco is also light, with its compressor weighing in at 9kg. And the compact body of the heat pump unit (outdoor unit) is 609mm high, 840mm wide, and 290mm deep.

Rather than diversification, Sanyo's heating products, such as the CO2 Eco Heat Pump, are meeting a need for environmental units, following the think Gaia concept which is driving environmental sustainable product development throughout the Sanyo Corporation.

Increasing concern

With concerns over global warming escalating end-users are increasingly concerned about the procurement of environmentally friendly products.

With condensing boilers having reached their efficiency pinnacle, hvac contractors can now confidently turn to heat pumps. By specifying heat pumps, contractors will be taking the next step in heating efficiency and impress their clients with their green credentials. And, with high-efficiencies, high water temperatures and ease of installation, CO2 air-to-water heat pumps are set to be the environmental heating solution of choice.