General Information; General Notes; Introduction - Hitachi RAS-H(V)RNME-AF Service Manual

1 General information

1.1 General information

1.1.1 General notes

No part of this publication may be reproduced, copied, filed or transmitted in any shape or form without the permission of
HITACHI Air Conditioning Products Europe, S.A.
Within the policy of continuous improvement of its products, HITACHI Air Conditioning Products Europe, S.A. reserves the
right to make changes at any time without prior notification and without being compelled to introducing them into products
subsequently sold. This document may therefore have been subject to amendments during the life of the product.
HITACHI makes every effort to offer correct, up-to-date documentation. Despite this, printing errors cannot be controlled by
HITACHI and are not its responsibility.
As a result, some of the images or data used to illustrate this document may not refer to specific models. No claims will be
accepted based on the data, illustrations and descriptions included in this manual.
No type of modification must be made to the equipment without prior, written authorisation from the manufacturer.

1.1.2 Introduction

The HITACHI's YUTAKI S system is a heating and cooling solution for the home with high energy efficiency. The system
consists of an outdoor unit (Inverter heat pump) and an indoor unit hydraulic module. The heat pump absorbs/sends heat
from/to the outside, and transfers it to the water circuit through the indoor unit hydraulic module.
YUTAKI S can be used both in winter time and in summer time, integrating heating and cooling systems, creating an air-
conditioned system and using just one energy source, the electricity.

For winter time
With the aim of reducing energy expenditure, there is a clear trend in the market to use medium and low temperature hea-
ting systems. Technological advances and improvements in insulation in the home enable to use of low temperature water
to heat homes. This results in more comfort and greater energy efficiency.
YUTAKI S meets the necessary conditions to provide this type of application, fulfilling user's needs.
The heat pump extracts the heat present in the air, increases its refrigerant temperature and transmits it to the water circuit
by means of indoor unit plate heat exchanger, where the heat is taken to radiators/(fan-coils), underfloor heating compo-
nents or both (2nd temperature area).
As well as increased efficiency and reduced CO
tem also boasts proven reliability and minimum maintenance. YUTAKI S provides a comfortable atmosphere all year long,
even in the coldest climates by means of the following system configuration possibilities:
• Mono-valent system: This is the most popular configuration. The air to water heat pump is sized to provide 80% of the
heating requirements on the coldest day of the year. An auxiliary electric heater (inside the unit) is used to provide the
additional heating required on cold days. This option usually results in an ideal balance between installation costs and
future energy consumption, as proven by its popularity in colder climates than ours, such as Sweden and Norway.
• Mono-energy system: The air to water heat pump is sized to provide 100% of the heating requirements on the coldest
day the year.
• Alternating Bi-valent system: For installations with an existing heating system by boiler and when is needed to heat the
supplied water temperature to the circuit up to high temperatures (80ºC), the boiler can be configured to alternate with
the air to water heat pump.
2
SMGB0070 rev.1 - 08/2011
emissions due to the extraction of free heat from the outside air, the sys-
2