Oilon RE 35, Installation And Operation Manual

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8 (67) RE01 1445EN
When using the heat pump as a water chiller (clean water circulates in the evaporator
instead of frost-proof solution), the evaporator must be protected from freezing. Usage
of flow switch on the evaporator side is highly recommended.
When maintaining the heat pump, note that adding and purging of a liquid refrigerant
from the evaporator with standing water can cause a frost damage.
1.7. Heat pump system dimensioning
Ground source heat pump can be sized to operate at
● partial capacity
● full capacity.
With partial capacity heat pump maximum capacity is sized up to correspond 60 – 80%
of a building’s maximum heating demand. In this case the heat pump produces the
most part of the building’s annual heat energy demand.
With partial capacity, heat pump operating periods are long during heating season.
This reduces the number of compressor stops and start-ups. During hardest freezing
periods at winter additional capacity from heat pump can be obtained with in-built
electric heater or oil boiler.
With full capacity, heat pump is sized up according to a building’s maximum capacity
demand, practically slightly over sized. With full capacity, the use of additional heating
capacity is minimised, thus in electric heaters’ case it is possible to use smaller fuse
size in electrical connection.
1.8. Collecting heat
Oilon RE heat pump’s heat source is usually a drilled well. The number and depth of
wells depend on heating demand. Soil or water can also be used as heat source. When
using water the piping is anchored to the bottom.
During heating period, the ground circuit fluid warms up a few degrees during
circulation. Collected heat is used to vaporise refrigerant in heat pump unit. Horizontal
piping requires applicable soil type and sufficient land area for piping. Applicable soil
types are fine grained and moist, such as clay or silt. Drilled well is suitable for all
locations except places where solid rock goes deep underground. When piping is
installed into water, building should be located sufficiently close to shoreline, preferably
less than 50 m away. Water should also be sufficiently deep, over 2 m right from shore.
In addition, waste heat from industrial processes can be used as heat source for the
heat pump.