Do you have to use heat recovery ventilation with a heat pump?
No is the short answer. A heat recovery ventilation system is purely to manage the ventilation of the building, providing fresh air and extracting stale air and steam. A heat recovery ventilation system will reduce the heat demand of the house regardless of the type of heating system as it reclaims a proportion of the heat that would have been lost in the air changes of the house.
Does a heat recovery ventilation system make much noise?
A properly specified and installed heat recovery ventilation system should be barely audible if at all. However whenever the unit is on boost mode the ventilation rate is increased so more air is moving through the vents and the sound may become noticeable but this is generally only when someone is having a shower.
Can I connect my cooker hood to the heat recovery ventilation system?
Some manufacturers in the past have toyed with this but have since discontinued with the principal. A cooker hood typically moves a lot of air, often more than the whole house ventilation rate would be, so to add this extra demand onto the heat recovery ventilation system would mean compromising the extract rate from the cooker hood or increasing the ventilation rate for the whole house by a lot. It is generally recommended to us a recirculating cooker hood with activated charcoal filter for dealing with the steam and odours from the cooker. With this the heat that the cooker produces is not just pumped outside as is done with an extractor hood. The heat recovery ventilation system would typically have an extract vent in the kitchen located between the cooker and the sink to extract whatever steam that escapes the cooker hood.
Do you see the heat recovery ventilation pipes in the house?
No. The heat recovery ventilation ducts (pipes) are all hidden above the ceiling level of the rooms. The only thing that is seen is the small white circular ceiling vent of which there would usually be one in each room.
Where is the heat recovery ventilation unit installed?
The heat recovery ventilation unit itself is usually located either in the attic space or in a plant room where other services for the building would be located.
Is there a S&E vent in every room with heat recovery ventilation?
Not usually. There is usually a supply vent in the likes of bedrooms, living areas, sitting rooms etc. The extract vents would be in bathrooms, WCs, utility, en-suites etc. This arrangement allows for the fresh air to be fed into the rooms where you spend most of your time. With the extract in other rooms it causes the air to flow from supply rooms in the direction of extract rooms ensuring a cross ventilation of the whole building.
Do I need wall/window vents with heat recovery ventilation?
No. The heat recovery ventilation manages all the general ventilation as well as the extract ventilation for the building so extra wall vents are not required. The only exception is where there is a fire place or stove in a room which must have its own dedicated air supply. This is usually done by installing a vent pipe from outside directly to the location of the stove or fireplace so as to not cause a draught in the room.
Does heat recovery ventilation cost much to run?
The cost to run a heat recovery ventilation system per year depends on the size of the house. The larger the house the more air needs to be moved and so the fans have to work harder. A house of 250m2 would cost in the region of €40 to €60 per year to run. The same system would reclaim an energy value roughly equivalent to 200 litres worth of oil per year.
Do I need bathroom fans with a HRV system?
No. The heat recovery ventilation system manages the extraction of the steam from the bathroom and reclaims some of this heat to contribute to the heating of the building.
How often do the filters need to be changed with a HRV system?
This depends on the air quality in the area and the amount of activity within the building. In some installations it is only necessary to vacuum the filters about once a year and change them every few years while in other installations the filters may need to be changed once a year.
Does HRV work with all types of heating systems?
Yes, it works independently of your heating system. The unit recovers the heat from the warm air in the house. It doesn’t matter how that heat was generated, whether by oil, gas, wood pellet, electricity, heat pump or any other source. However, it is important to choose a heating system that will suit your needs.