Heat recovery

Recovering energy with ventilation systems can result in an enormous reduction of heating costs because up to 95% of the warmth inside the room is preserved despite ventilation. There is a solution for every situation, centralised and decentralised systems provide outstanding performance and recovery.


How does heat recovery work?

People and heating energy generate warmth inside the room. However, frequent ventilation is important, and the warm air will escape through windows and doors if the air change is not monitored correctly. Energy-efficient methods of heat recovery can absorb most of the heating energy of the warm air and pass it on to the new, incoming supply air.

On one hand thisis done by guiding supply and exhaust airflows so they are directly crossing each other and exchange heat. An indirect exchange is realised by conductive intermediate parts (recuperators). A perfect example are radiators whose metal housing emits the heating energy of the hot water and therefore warms up the room.
Another possibility are heat storing materials such as ceramic regenerators that exhaust and supply airflow pass through after each other (semi indirect transfer). Although these processes seem to be simple they can transfer up to 95% of indoor heat.

Heat recovery can be combined with all kinds of heating systems except appliances working with infrared radiation. Whether you are using a radiator, oven or fireplace to supply warmth for your home makes no difference at all – energy will be recovered. The results remain the same, you will notice a decrease in the consumption of raw materials: You have to use less material to keep on fuelling the heat source, meaning you will save costs yet enjoy a cosy atmosphere.

Centralised heat recovery

Central ventilation systems are generally set up in buildings that are thermally insulated. How many rooms and what surface each unit can ventilate is stated in the detailed description of the item. We are offering models with up to six ports for connection to extractor ducts, which means that up to six separate rooms can be ventilated. In spacious buildings special attention should be paid to damp rooms and their sufficient ventilation via individual ducts, rooms that are used rarely can be connected to those ducts and supplied with fresh air through special openings as well. A professional installer will be able to help you determine the required flow rate and draft a plan for the installation of the system.

The installation of central units is very simple and user-friendly, they can be mounted in cellars, attics and other easily accessible places. The devices are made of robust plastic to ensure durability, a special IP code protects them from splashing water and water vapour.

Decentralised solutions

Decentralised ventilation systems that extract air from a room directly to the outside of the building can also be applied in old buildings with relatively little time and effort spent on installation. Decentralised solutions are ideal for environments that experience a lot of humidity, such as bathrooms and kitchens. Contrary to ventilation through opening windows, decentralised systems can recover up to 90% heat. Another plus is the automated running, no manual operation is required – sensors determine whether or not the water vapour content in the air is above average and immediately react by activating countermeasures. The third benefit: The outside air that enters the system is always cleaned and filtered before it reaches the rooms on the inside.

The systems can be mounted to one wall, it is also possible to use longer pipes and tubes and guide the airflow through separate rooms. A consulting engineer will be able to help and determine whether or not structural alterations need to be done. For instance, if there is only one utilisable opening, reversible appliances are the best choice. Supply and exhaust airflow are guided through a shared heat store.

The illustration on the right hand side shows the TwinFresh Comfo ventilation system. Even during sub-zero temperatures the outside air is heated up by heat transfer to the recommended value of 20°C before it is passed on to the inside. Chilly outdoor air and even snow is kept away by thermally controlled covers. There is no need to fear cold draught with these highly advanced products.

Accessories and controls

Ventilators are usually mounted near the ceiling because that is where the most warm air is located in the room. Even though the system is out of reach, you can still control them with a convenient remote control or wall controller. The wall controller unit is connected to an additional transformer can operate up to four devices at once. After it has been installed by an electrician, the controller is used just like a regular light switch and greatly facilitates usage in spacious rooms. In case of central installations (e.g. in attics) and easily accessible decentralised fans these settings can be controlled directly on the device.

On top of controllers creoven offers a variety of accessories that are required for the installation and operation of your new ventilation system. That includes mounting kits for suspended, free-standing, corner, ceiling or wall installations. The mounting kits are often already included in the deliveries of central ventilation appliances. Our accessory section is your go-to place for other extras such as transformers, speed controllers and sensors.

Replacing filters and maintenance

Apart from filtering impurities like plant parts and fine particles out of the supply air, most heat-recovering devices with reverse function require high-quality filters. Not only greasy fumes from the itchen, but also general pollutants such as lint, hair and other particles are prevented from interfering with the sensitive electrics on the inside of the fan.

The filters on outside inlets should be robust and flexible to hold of intruding insects or twigs and pebbles drifting in the wind. The openings should be relieved of leaves, dirt and brances about once a month. Generally it is sufficient to clean it with a hoover or wipe off the debris. The air ducts on the inside of the building are also subject to pollution and can lead to overheating of the motor in the long run. According to the classification of the filter it should be replaced every 12 to 24 months. Filters in appliances installed in kitches should be checked and replaced more often as there is a higher risk of odour nuisance and grease scaling. If the access is hard to reach, consult a professional installer to help you with the exchange of the filter. That way you can be sure that the purifying fleeces are inserted in a workmanlike manner..

The activated carbon filter (centre) is located in front of the heat reservoir. Sometimes they are protected by plastic grilles (white) that keep away particles that might have been sucked in.