We are offering this Passive House certified MVHR/ heat pump combination in co-operation with Nilan Green.
A two-stage MVHR & Exhaust air heat pump with integral water cylinder. The Nilan Compact P2 is a unique solution for heating and hot water production. The compact unit requires no external components.
Compact P2 is not a traditional ventilation unit. In contrast to other ventilation units, it recovers 100% of the heat from the extract air. The counterflow heat exchanger makes it possible to recover up to 95% of the energy in the extract air. This is then used to heat the outdoor air. The integral heat pump will utilise any remaining energy for producing domestic hot water.
The Compact P2 is ideally suited for energy efficient, smaller dwellings up to 140 m2 floor area. It combines all domestic services in one cabinet:
1) Ventilation: Continuously operating heat recovery ventilation (MVHR) (unlike some competitors that switch off the heat recovery when the heat pump is running).
2) Hot water (DHW): The heat pump provides hot water, which is stored in the 180l cylinder. The system can produce about 240l of blended hot water. The heat pump is fed by the exhaust of the MVHR system, which boosts the efficiency of the heat pump in frosty weather.
3) Space heating and cooling: When the hot water has been heated, the heat pump then can add either 1kW of heat or cooling into the supply air stream.
The Nilan Compact P2 is the updated version of the Compact P. It houses the MVHR unit, the heat pump, the 180l water cylinder and the expansion vessel.
If there is restricted space, a narrower version, the Compact S ia available, which is only 600mm wide. For this version the expansion vessel needs to be placed next to it.
Airflow (see planning data for SEL/SFP values):
Min : 100 m3/h
Max : 425 m3/h
Please find below the 5 different working modes of the Compact P/ Compact S:
Passive heat recovery occurs via a counterflow heat exchanger with a temperature efficiency of up to 95%. The outdoor air is heated by the extract air. This ensures the least possible heat loss from the ventilation process.
Due to the high level of heat recovery, ice may form in the exchanger during winter. The control system has an efficient de-icing function that will de-ice the exchanger if necessary. Alternatively, Compact P2 is available as a Polar model, which has an integral pre-heating element for frost protection. This ensures that ice cannot form in the exchanger, and it provides full heat recovery throughout the winter.
When the integral heat pump in the ventilation part is not producing domestic hot water, it can heat the supply air even further and thereby help heat the dwelling.
This only happens when the indoor temperature or the supply air temperature falls below the value specified in the settings.
When the heat pump heats the supply air, the domestic hot water is also heated slightly at the same time. The temperature may therefore exceed the one that you have set as your desired hot water temperature.
The integral heat pump uses the energy in the extract air that has not been recovered by the counterflow heat exchanger. It uses this remaining energy to produce domestic hot water.
There is software-based scald protection of 60 °C, which means that the temperature in the hot water tank will not exceed this.
Compact P2 is available with a solar coil mounted in the hot water tank. If the requirement for domestic hot water is very high, the solar coil can act as supplementary heat source.
You can connect different energy sources to help heat the domestic hot water such as solar panels, district heating or a GEO geothermal heat pump.
When the internal temperatures rise above a variable set point, outdoor temperature is above 14 °C, the unit will operate in summer mode and shut off the heat recovery if its colder outside than inside. The unit will then slightly cool the indoor air. (If it’s colder than 14°C the bypass will not activate.)
Active cooling (with the heat pump) is much more effective in comparison than bypass cooling.
The heat pump in the ventilation part is reversible. This means that it can both heat and cool the supply air.
When the outdoor temperature is above 14 °C, the unit will operate in summer mode. The unit will then cool the indoor air if the indoor temperature gets too high according to the values specified in the settings.
When cooling, the unit will first attempt to do so by means of the bypass function. If this proves inadequate, it will begin to cool actively via the heat pump.
This requires that the active cooling function has been activated as the process uses electricity. But it is not wasted because the heat that is extracted from the supply air is transferred to the hot water tank.
AIR9 is an Air-to-Water Heat Pump as an optional extra that can be combined with the Compact P2/ S. It adds space heating power to the Compact System. Cooling is only provided by the Compact unit.
It is intended for large dwellings with a ventilation requirement of up to 275 m3/h.
By integrating all three installations in just one installation, you save considerable space in the plant room. Another advantage is that the control systems work in unison, which enables energy efficiency and thereby an overall saving in energy consumption.
This simple graph shows which dwellings particularly suit the four common domestic Nilan systems:
Unfortunately the Compact P range of systems has not yet been listed on the Ofgem Product Eligibility List for the Boiler Upgrade Scheme.
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