Developing a 1.2 kW air-to-air single-room heat pump unit for heating, ventilation, and air-conditioning

Final Report Summary - HEATPUMP (Developing a 1.2 kW air-to-air single-room heat pump unit for heating, ventilation, and air-conditioning)

Executive Summary:
HeatPump - Developing a 1.2 kW air-to-air single-room heat pump unit for heating, ventilation, and
air-conditioning. EC Grant agreement no.: 243647

The main objective of this project is to develop a 1.2 kW air-to-air single-zone heat pump unit for
heating, ventilation, and air-conditioning. The aim is to present the next generation of modular, air-to-air heat pump for single-zone applications and to provide the group of SMEs and AGs with key technologies and prototype/demonstration units. The most unique feature of this heat pump is that the fan function will be integrated with the condenser and the evaporator, enabling a compact construction and needing only one motor. To accomplish this, the major part of the construction needs to be rotating.

The background for this work is that shortage of supply and increasing cost of energy has raised consumer and governmental awareness of the need to reduce energy demand and to raise the efficiency of energy supply, not least for space conditioning. In response to European directives, future heating demand will be drastically reduced in the built environment and IEA, in its Energy Technology Perspectives of 2010, has pointed out that this will increase the share of electricity as the main energy carrier. To use electricity efficiently for space conditioning the heat pump is recognized as a main contender. However, the future situation of much reduced heating demand and less reduced cooling demand requires a new type of low-cost, controllable, efficient and low-noise heat pump that provides comfort by an environmentally benign technology.

The EC supports this path to the future by means of regulations that affect three main areas: 1) requirements on and promotion of retrofit energy-saving devices; 2) protection of people and the environment from noise and unfriendly chemicals; 3) aesthetics and functionality of equipment. Therefore, there is increasing need for more efficient and cost-effective heat pumps that can be used in
a multitude of applications such as residential buildings, hotel rooms, offices, motor homes, modular homes, and electric cars. Thus, to match the demands of the future heat pump market the HeatPump consortium is developing this new and innovative solution for space heating, space cooling and ventilation.

Our idea has been to develop a retrofit technology that will provide local control of heating, cooling and ventilation with a modular approach. Each unit is for single-zone operation but any number of units may be combined for multi-zone operation. Overall control is synchronized and optimized by means of a wireless central supervisory control and data acquisition system. The design objective for the new scalable heat pump unit is a competitive COP rating at part-load (4.7 at +7 °C), a low external noise level (35 dBA at 10 m) and a competitive life-cycle cost (purchase, installation, operation and recycling). This project will also consider integration of the zone ventilation requirement into the unit, thus providing a packaged heating, cooling and ventilation unit. The heat pump becomes a combined outdoor and exhaust air unit with highly efficient heat recovery.

The work is co-financed by the European Commission under the topic "Research for the Benefit of SMEs" of the 7th Framework Programme. Information about the HeatPump project, its partners and objectives is available on our website www.euroheatpump.eu.

Project Context and Objectives:
The main objective of this project is to develop a 1.2 kW air-to-air single-zone heat pump unit for
heating, ventilation, and air-conditioning. The aim is to present the next generation of modular, air-to-air heat pump for single-zone applications and to provide the group of SMEs and AGs with key technologies and prototype/demonstration units. The most unique feature of this heat pump is that the fan function will be integrated with the condenser and the evaporator, enabling a compact construction and needing only one motor. To accomplish this, the major part of the construction needs to be rotating.

Project Results:
The first period of the project comprised mainly work packages 1 and 2 on scientific development and technological research respectively. This third period has concentrated on work package 3, technological development. The efforts needed for this development has shown to be considerably higher than initially expected. The focus has been on a development, construction, assembly and testing of prototypes of the key components that represents the areas where this heat pump will be different than existing ones in this size. The key components are 1) the electric motor and drive, 2) a compressor that benefits from rotating conditions and 3) evaporator and condenser heat exchangers with integrated fan function. For period 3, due to the complex amendment process, activities only focussed on finishing the developments already ongoing before the amendment was approved. Since the amendment was not approved until the end of the project, no new activities could be started. As a result, the final product from this project is an almost complete prototype heat pump.

1) Electric motor and drive prototypes: A new, optimized variable-speed-drive motor has been realised in Period 2.

2) Compressor prototypes: An existing prototype, purchased during period 1, has been modified and equipped with new impellers with improved design. During period 2, a few preliminary test runs were carried out, showing satisfactory flow capacity, but unsatisfactory pressure ratio.
In period 3, the problems with the liquid ring oil was addressed and reconstructions of the mechanical components were carried through. The construction is ready, and balancing was made.

3) Heat exchanger with integrated fan function prototypes. An existing fan prototype was tested and found to have too low efficiency, compared to theoretical calculations. As part of WP2, several design concepts were investigated and analysed theoretically, partly assisted by CFD calculations. Two designs, out of a total of four presented, were chosen as most promising, and for the more compact one of these, a prototype was designed, manufactured and tested during P3.The cross flow fan design turned out to have too low heat transfer properties compared to what is required per volume of fan. Enhancements to the heat pipes are required to improve the heat transfer and further modelling work was carried out to improve the design. An ideal screw-type fan would be feasible with the given geometric constraints. A screw-type fan would need a mating rotor, just as in a screw-type compressor to generate the necessary pressure difference. This will be much too complicated and costly in this specific application and we resorted to plan C with a radial fan design.

Potential Impact:
We expect the project to generate an efficient, quiet and cost-effective heat pump solution for single-zone applications. The modular approach facilitates scaling of units and use of multiple units to provide solutions for a multitude of applications.

Employment: The HeatPump project is expected to create new EU jobs in parts manufacturing and production-related technical service (50 new employees are expected by year 2 post-project), assembly and quality control (40 new employees expected) and marketing, product management, sales, and installation (expected 1 additional employee per €1 Mn of annual revenue, or 50 employees after year 1 post-project to 750 employees by year 4 post-project).

Environment: In accordance with EC guidelines on pollution prevention, reduction of emissions, and
conservation of natural resources, the HeatPump product will be designed to use a natural refrigerant that is thermodynamically efficient and has a low environmental impact. Design work will specifically aim at a solution that only requires a small quantity of refrigerant. High unit efficiency, unit construction and simple installation will ascertain that purchased energy will be low in practice as well as in theory over a long predicted lifespan. Low total cost will contribute to market penetration and thus to the total energy savings and reduction of environmental impact (market penetration is important; environmental effect is achieved only by units that are in actual operation and functioning as intended).

Society: Upcoming EC regulations (expected full compliance by 2015) require the phasing out of heating, ventilation, and air-conditioning (AC) devices that are inefficient and noisy contributors to CO2 emissions and energy waste. In compliance with the Energy Performance of Buildings Directive (EPBD), display energy certificates (DECs) have been introduced for residential buildings (mandatory since 2006). Corresponding DECs will be introduced for industrial buildings to replace the currently used energy performance certificates (EPCs) and there is already in 2008 a requirement for compliance with directive 2002/91/EC and the modified 2003/0056 COD, Energy Directive 2004/8/EC (amending Directive 92/42/EEC, the Environmental Noise Directive 2002/49/EC) for heating and ventilation units. Also, the European Commission is developing standards such as EN ISO 13790 for air-conditioning systems and lighting and 'Calculation of Energy Use for Space Heating'. The EC regulations also call for phasing out ventilation and heating systems that do not meet the increasing ecological requirements (compliance with the EPBD) and the EU schedule for the Phase-Out of HCFCs (expected full compliance by 2015), and impose requirements on the aesthetics of HVAC equipment. In particular, EU Directives 2002/95/EC and 2002/91/EC on reduced energy use and the aesthetic nature of facades of residential buildings is applicable to outdoor heat source and ventilation units.

Compliance with standards: The heat pump will be designed to comply with all relevant European and international standards. As soon as possible the HeatPump Exploitation Board will start interacting with the relevant CEN standards committee for consumer-product approval to substantiate and possibly revise its view on the optimal development route. The AG members will compare the requirements of end-users from East, West, North, and South of Europe and the existing standards to start the pan-European certification process as early as possible.

List of Websites:
www.euroheatpump.eu

Final Report Summary - HEATPUMP (Developing a 1.2 kW air-to-air single-room heat pump unit for heating, ventilation, and air-conditioning)

Related documents

Share this page

Download