Brief Description - Daikin Altherma ST EKHWCH300B Installation And Operating Manual

2‒5 300 l P‑models
2.2

Brief description

The hot water storage tank is a combination of heat storage tank and
instantaneous water heater.
The pressureless storage water serves as heat storage medium.
Useful heat is supplied and removed via the spiral corrosion-
resistant heat exchanger, which is made from a corrugated stainless
steel pipe (1.4404), and is completely immersed in the storage tank
water. In the heat exchanger for domestic hot water generation,
domestic hot water is stored at the temperature level of the
preparation zone.
The cold water which flows in when the hot water is drawn off is first
routed to the storage tank at the very bottom of the heat exchanger
(WT1), where it cools the lower zone of the storage tank down as
much as possible. The readiness zone is heated by an external heat
generator (condensing boiler, heat pump, solar system, electric
immersion heater). Water flows through the heat exchanger for
storage charging (WT2) from top to bottom.
On its way to the top, the domestic water continuously absorbs the
heat of the storage tank water. The flow direction, operating on the
principle of counter-flow, and the coil-shaped heat exchanger create
a pronounced temperature layering in the hot water storage tank. As
high temperatures can be maintained for a very long time in the
upper section of the storage tank, a high hot water output is
achieved even if water is drawn off over a long period of time.
The hot water storage tank
components" [ 4 6] can be heated by solar in addition to the external
heat generator. Depending on the available heat from the sun, the
entire hot water storage tank can be heated up.
The stored heat is now used both for hot water generation and for
heating support. The high total storage capacity also temporarily
allows time without sunshine to be bridged.
EKHW(D/C/P)(300/500)(P)B
Daikin Altherma ST (Hot water storage tank)
008.1633099_00 – 06/2020
listed in "2.1 Design and
If a heat pump system is used as an external heat generator, the
primary hot water storage tank can only be one of the EKHWP-
models.
Optimum water hygiene
Low flow or unheated zones on the domestic water side are
completely excluded with the hot water storage tank. It is impossible
for sludge, rust or other sediments to be deposited, as can be the
case with other large volume tanks. The water which is fed into the
system first is also discharged first (first in, first out principle).
Low maintenance and corrosion
The hot water storage tank is made of plastic and is completely
corrosion free. No sacrificial anode or similar corrosion protection
system is necessary. This means that associated maintenance work,
e.g. changing the protective anodes or cleaning the storage tank,
does not need to be carried out on the hot water storage tank. Only
the fill level of the storage tank water needs to be checked.
The corrugated stainless steel pipe heat exchangers on the heating
and potable water side are made from high quality stainless steel
(1.4404).
Low calcification
On the pressureless storage tank side only once deposition of
limescale is possible. The immersion heater therefore remains clean,
as do all the stainless steel heat exchanger pipes in the storage tank
water. This means that no limescale can build up which would
continuously reduce the efficiency of heat transfer in the course of
operation (as is the case with other storage tank designs).
The thermal and pressure expansion and high flow rates in the
domestic water heat exchanger release any possible limescale
deposits, which are then flushed away.
2 Product description
Installation and operating manual
11