Questions regarding ventilation units

A ventilation system equipped with heat recovery removes warm, humid, and stale air from areas like the kitchen, bathroom, and utility room within the home. Meanwhile, fresh outdoor air is directed into spaces such as the living room, bedrooms, and study. The chilly outdoor air is efficiently warmed in the heat exchanger using the heat from the extracted air. This process enables the recovery and reutilization of energy from the extracted air.

Passive heat recovery is a procedure conducted within a high-efficiency counterflow heat exchanger. The process involves the transfer of heat from warm extract air, entering one side of the exchanger, to cold outdoor air, which enters from the opposite side. This heat exchange occurs within the exchanger, resulting in the transfer of thermal energy from the extract air to the fresh outdoor air, which is subsequently distributed into the dwelling.

Active heat recovery takes place through a heat pump, which extracts heat energy from warm extract air using an evaporator. This reclaimed heat energy is subsequently transferred to cold outdoor air through a condenser. Unlike passive heat recovery, active heat recovery is not expressed as a percentage; instead, it is quantified using a COP (Coefficient of Performance). COP measures the energy output in kilowatts (kW) in relation to the energy in kW required for operation. For instance, a COP of 4 indicates that for every 1 kW of energy consumed by the heat pump, you receive 4 kW of heating energy. With a heat pump, this often results in heat recovery exceeding 100%.

The heat pump is equipped with a reversible cooling system, allowing it to warm the supply air during winter and cool it during summer. 

Several of Nilan's ventilation units are outfitted with both a counterflow heat exchanger and a heat pump. The primary heat recovery process takes place within the counterflow heat exchanger. Nevertheless, when there's a need to provide additional heat to the dwelling through the supply air, the heat pump becomes active, enhancing the heat transfer into the supply air. Conversely, when cooling is necessary, the heat pump reverses its cooling cycle to cool the supply air.

In the case of new construction projects, you have the opportunity to make an early decision during the planning phase to include a ventilation unit in your design.

For existing dwellings, it can occasionally pose a challenge to retrofit ventilation ducts throughout the structure. In such cases, it is advisable to consult with a qualified expert to assess the feasibility of installing ductwork in your residence and to determine the most suitable ventilation unit for your specific circumstances. 

The noise level generated by a ventilation unit is contingent on whether it incorporates passive or active heat recovery. Ventilation units equipped with passive heat recovery typically generate minimal or negligible noise. In contrast, units with an integrated heat pump may produce slightly more sound, but their noise levels are typically akin to that of a standard refrigerator or freezer.

Nilan manufactures a variety of ventilation units available in different sizes, featuring duct connections either positioned on the top or on the side of the unit. A top-ducted unit is commonly installed within a tall cabinet, while a unit with side duct connections can be conveniently installed, for example, in an unused attic. 

Installing a ventilation unit with air-to-air heat recovery typically doesn't require council approval. Nevertheless, it's crucial that the unit adheres to the power consumption and heat recovery standards outlined in the current Building Regulations.

If you lack experience in dimensioning and installing ventilation units, we strongly advise enlisting the services of a qualified expert to handle the installation.

To ensure a comfortable and healthy indoor environment that safeguards against illness and protects the building from issues like mold and dry/wet rot, proper ventilation of your residence is essential.

Indoor air quality is constantly compromised by various sources, including furniture, carpets, wall paints, and electrical appliances, all of which release chemicals and gases. Additionally, particles from activities like candle burning and cooking (especially roasting and baking) have been linked to cardiovascular diseases. Effective ventilation is crucial for removing both these particles and chemical gases produced by cleaning products.

Excess dampness is another source of indoor pollution. During the winter, excessive humidity levels can not only affect your health but also cause structural damage to the building. When humidity surpasses 60%, it provides an ideal environment for dust mites, while levels exceeding 75% can lead to mold and dry/wet rot, potentially damaging the building.

Thus, ensuring proper ventilation is of paramount importance for maintaining a healthy and safe living environment.

In the winter, during extended periods of subzero temperatures, especially when daytime temperatures remain below freezing, ventilation can result in a drop in indoor humidity levels, reaching as low as 20%. This decline can result in the development of cracks in various surfaces, including wooden furniture, wooden floors, and walls. Additionally, residents may experience increased dust circulation, which can be quite inconvenient.

It's important to note that these issues are not unique to the ventilation unit itself. The unit's primary function is to ensure compliance with Building Regulations by maintaining the required minimum air exchange rate. Natural ventilation can lead to similar problems when the Building Regulations are adhered to.

Every ventilation unit from Nilan is equipped with a smart humidity control system. This system can be configured to minimize ventilation during brief periods throughout the year when the indoor humidity might drop to exceptionally low levels. By doing so, it effectively prevents the indoor humidity from reaching levels that could lead to problems within the dwelling.

Researchers suggest maintaining indoor humidity levels within the range of 30% to 60% as this range provides the least favorable environment for the proliferation of bacteria and viruses.

Many people with allergies notice a significant enhancement in their well-being after the installation of a Nilan ventilation unit, thanks to the resulting improvement in the indoor environment. For any of Nilan's ventilation units, you have the option to acquire a pollen filter as an additional accessory. This filter effectively removes pollen from the incoming outdoor air, minimizing the impact on your indoor comfort.

All Nilan ventilation units proudly feature the CE marking, indicating their official approval for distribution throughout the European market.

To comply with Building Regulations, these units must meet rigorous standards related to power consumption, heat recovery efficiency, and noise levels. Nilan's ventilation units effortlessly exceed these requirements, delivering exceptional energy efficiency and maintaining remarkably low noise emissions.

In accordance with EU regulations, ventilation units equipped with passive heat recovery must adhere to the Ecodesign Directive. Consequently, Nilan is obliged to provide product data in a specific format to enable consumers to make well-informed product comparisons. Additionally, the EU conducts thorough market surveillance to ensure the accuracy of the data provided by manufacturers.

The optimal selection depends on your individual requirements, taking into account variables such as the dimensions of your residence and your preferences for multifunctional capabilities like heating, cooling, and domestic hot water provision.

To obtain a customized solution and pricing that aligns with your specific needs, we encourage you to contact a Nilan dealer who can conduct a thorough evaluation of your distinct requirements.

Energy consumption varies depending on your choice of ventilation unit model and your usage patterns. Typically, power consumption falls within the range of 300 to 2,000 kWh per year. For a comprehensive breakdown of the estimated power consumption for individual ventilation units, we recommend consulting the 'Ecodesign Data' section within the product datasheet.

Nilan ventilation units are generally engineered with a lifespan that exceeds 20 years.

There are no legal restrictions prohibiting self-installation of the ventilation unit. Installation and software instructions can be downloaded from our website in the 'Downloads' section.

Nonetheless, we strongly advise engaging a certified dealer to handle both the installation and system balancing. This process demands specialized knowledge to ensure optimal performance, minimal power consumption, and reduced noise levels.

Regular maintenance is essential to ensure the long-term and efficient operation of your ventilation unit, similar to the way a car requires maintenance to avoid breakdowns.

The primary maintenance task involves replacing the filters when they become dirty, usually around four times a year. Additionally, an annual check-up is recommended for the unit's overall well-being. A comprehensive outline of the maintenance procedures can be found in the User Manual specific to your ventilation unit, which is available for download in the 'Downloads' section.

You have the option to purchase filters conveniently online from Nilan Ireland. To ensure you receive the correct filters, please specify the model and age approximation of your ventilation unit. 

Link to the order form

The main purpose of the filter is to safeguard the ventilation unit. You can acquire the same filters as those originally supplied with the unit upon delivery, known as ISO Coarse > 65% (formerly known as G4 filters).

If anyone in your household suffers from allergies, we recommend considering the purchase of a pollen filter labeled ISO ePM1 50-65% (formerly referred to as an F7 filter). This filter effectively captures the majority of pollen from the outdoor air. The pollen filter boasts a larger filter area, which means it doesn't require replacement as frequently as the standard filter.

We advise all our clients to book a service call out with one of our qualified and certified Nilan technician. Fill in the Request service call-out form on our website. 

Link to service call-out form

The dirt that may accumulate around the valves does not originate from the ventilation unit itself. Instead, it arises due to turbulent airflow around the valves when air is either entering or exiting. This turbulence stirs up dust within the room, causing it to settle around the valves on the ceiling.

During the cleaning of the valves and their surrounding area, it's crucial to exercise caution and avoid adjusting their settings, as this could disrupt the overall system balance.

In residences featuring expansive south-facing windows or inadequate insulation, it is common to observe significant temperature variations from early spring to late autumn whenever the sun is shining. This can lead to uncomfortably warm conditions during the summer, posing a considerable challenge for the residents.

Hence, it is frequently held responsible for causing the indoor environment to become excessively warm in the summer months. In actuality, though, a typical ventilation unit has a relatively minor influence on increasing the temperature within the dwelling during summer. Even in cases where it lacks a 100% bypass and delivers outdoor-temperature air, its impact on indoor temperatures remains limited, given that the air exchange occurs only ½ a time every hour.

We frequently receive inquiries about whether a ventilation unit can provide cooling during the summer, but this is not its primary function. In a typical residential setting, the air exchange rate occurs only half of the time every hour. To achieve effective cooling, an air exchange rate of 7-10 times per hour is required, which is beyond the capability of a standard residential ventilation unit.

Nilan offers ventilation units featuring an integrated heat pump, primarily designed for heating the dwelling during the winter months. In the summer, the reversible heat pump can also provide a cooling effect, reducing the supply air temperature by up to 10°C. However, the cooling capacity is constrained by the lower air exchange rate typically found in residential settings.

During the cooling process, humidity is extracted from the supply air. As a result, the indoor environment shifts from, for instance, 28°C with 80% humidity to a more comfortable 25°C with 60% humidity. This reduction in humidity enhances comfort levels in warm conditions, which is why we refer to it as 'comfort cooling'.

The most effective approach is to prevent heat from entering the residence in the first place, and this can be achieved through external shading solutions like blinds or curtains.

For instance, a window with low-e glass and no sun screen emits approximately 600W of heat per square meter. You can then easily calculate the amount of heat that enters your dwelling. When using window sun screens, the windows emit approximately 90W of heat per square meter, a substantial reduction in heat transfer that requires minimal energy.

If you opt for external shading, we recommend selecting screens equipped with a control system that can detect both outdoor and indoor temperatures. This way, they will only block out the sun when the indoor temperature becomes uncomfortably high, allowing you to harness the sun's warmth during periods when it is desired.

Get in touch with the dealer from whom you made the unit purchase, whether it was through an in-person transaction or an online purchase.

In extremely cold outdoor temperatures, it's not uncommon for ice to form in the counterflow heat exchanger of a ventilation unit with high heat recovery efficiency. This phenomenon arises when frigid outdoor air encounters the moisture-laden extract air within the counterflow heat exchanger. The humidity in the extract air freezes over time, leading to ice buildup. To address this, regular de-icing is necessary, a process managed by the integrated control system of the ventilation unit.

During de-icing, the supply air temperature may temporarily drop below its usual operating level. To initiate de-icing, you redirect the cold outdoor air to bypass the counterflow heat exchanger by opening the bypass damper. The heat extracted from the extract air is then employed to thaw the frozen ice within the heat exchanger.

In rare instances, the counterflow heat exchanger may not be effectively de-iced, and ice can accumulate until it obstructs the exchanger entirely. Such occurrences are infrequent and are often linked to other issues like incorrect unit installation or poorly insulated ducts. In the event of complete ice blockage, you can remove the counterflow heat exchanger from the ventilation unit and thaw it by rinsing it with hot water in a shower.

To proactively prevent ice formation in the counterflow heat exchanger, it is advisable to install a pre-heating element for frost protection. This heating element ensures that the incoming outdoor air never falls below 0°C, mitigating ice formation. It is also a cost-effective solution. For more detailed information, please refer to the datasheet for your ventilation unit, available in the 'Downloads' section.