Gree expands R290 portfolio with portable ACs and dehumidifiers

Although the most common R22 replacement in China is R410A, this is not ideal because of high Global Warming Potential (GWP), according to the presentation by Stephanie Zheng, Gree Electric Appliance. With this in mind, the company started research on R290 in 2006 and officially launched in July 2011 the production of R290 split room ACs for which it has received the first global VDE (VDE, the Association for Electrical, Electronic &Information Technologies) certification.

Features of the new R290 packaged portable ACs

Aiming to develop multiple kinds of R290 air conditioning products, the company has more recently focused its R&D efforts on other types of low charge equipment for which restrictive standards do not apply, namely portable ACs and dehumidifiers.

The new Gree portable AC features:

• 2.6kw
• Efficiency increase of 10%
• Own-designed compressor
• VDE certified

10% energy efficiency gains and lower cost for R290 portable AC compared to R410A

The presenter also provided an overview of how the changes in the different components have impacted the cost of the new AC unit compared to the base case of an R410A portable AC:

• Size and cost of compressor will increase, as the discharge volume of compressor increases
• Lower refrigerant cost, as the required charging volume decreases significantly
• Energy savings, with the efficiency increasing by 10%
• More than 25% lower cost for heat exchangers, as their size decreases significantly
• Increase in cost of electric components

Despite the increase in the cost of the compressor, the cost of the complete unit is lower than the R410A unit.

Safety aspects

The unit features:

• Explosion-proof design of key electric parts
• Warning label for users or maintenance technicians
• The electrical part is on the top of the unit, to avoid the gas subsidence
• The internal air flow system of the unit is completely through from the bottom to the top, so that in case there is gas inside, it can flow out

R290 in dehumidifiers: 35% increased efficiency but at increased cost

The new R290 dehumidifiers feature:

• Low charging volume, namely 60g for the 10L model and 70g for the 20L one
• Efficiency increased by 20%
• Self-developed compressor
• VDE certified
• Safety features similar to the portable R290 AC unit

The energy efficiency is improved by about 35%. Regarding costs of the different main components:

• Cost of heat exchanger is decreased by about 38%
• Cost of compressor is increased due to processing technique

In this case, however, Gree estimates that the cost savings will not exceed the cost increase of the compressor and hence the overall cost of the R290 dehumidifier unit will increase.

R290 ideal refrigerant but advancement with after-sales market is key

Concluding her presentation Ms Zheng stated that R290 is more environmental friendly, energy-saving and cost-saving compared to traditional refrigerants such as R22 and R410A. However, she noted that the precondition before expanding the application of R290 is addressing the challenges of design safety, production safety, operation safety and maintenance safety. While Gree has already addressed the first two, consumer awareness as well as a normative after-sales market is still needed.

R290 rotary compressor concept by Guangdong Meizhi targets larger systems

During the same session, Chen Zhenhua of Chinese compressor manufacturer Guangdong Meizhi presented the technical characteristic of R290 rotary compressors and recommendations for their application.

The presenter pointed out the restrictive nature of standards with regards to maximum allowable refrigerant charge, noting that a formula used in standards to determine such values might not be justified.

Against this backdrop and given that the compressor plays an important role in reducing the refrigerant charge, Meizhi has a design concept for a compact R290 rotary compressor that targets AC manufacturers that aspire to make a larger system possible.

After going over some of the characteristics of the compressor, the presenter highly recommended a higher superheat in R290 cycle system.