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Aquarea air / water heat pump – design handbook 07 / 2014
Project Design
Planning heat source – air
Monobloc system
Attention
In monobloc systems, there is a risk of freezing if the heating circuit
is filled with water and the outside temperature falls below +4 °C.
That can cause significant damage to the device.
Freezing must be prevented on-site through one of the following
measures:
1. The heating circuit is operated using a foodstuff compatible
anti-freeze mixture (propylene glycol).
2. An auxiliary heater unit in the monobloc unit prevents the heating
circuit freezing.
3. The heating circuit is drained by a system to be provided by the
customer (manual or automatic).
Note
For details on preventing water pipes freezing, and heat and cold
protection, see the Guidelines BS 5422 and BS 5970.
5.9.2 Monobloc system
The monobloc system consists of a unit containing one or two fans,
depending on the power class and model. The units differ in physical
size (see overview on page 3).
The water pipes between the monobloc unit and the building are heat
distribution pipes that are laid directly adjacent to the outdoor air. Accord-
ing to the current energy-saving directive (EnEV 2014), these pipes are
to be thermally insulated with a least twice the minimum thickness as per
Annex 5, Table 1, Lines 1 to 4, but with a thickness of at least 40 mm,
based on a thermal conductivity of 0.035 W / (m × K).
