Home ventilation systems for controlled ventilation are becoming more and more popular. However, starting from an existing single-family house, retrofitting a ventilation system is extremely time-consuming and costly. The more the question arises as to how useful controlled ventilation is.
Exhaust systems convey the stale air to the outside. There are central and decentralized ventilation systems. These systems are sufficient to regulate the air humidity, but heat recovery is not possible.
There is one exception concerning heat recovery: With central exhaust air systems, it is possible to use the residual heat in the exhaust air via a heat pump.
Central Supply And Exhaust Air Systems With Heat Recovery
There is usually a cross-counterflow heat exchanger for heat recovery in the basement or in the attic with these ventilation systems. The fresh air is drawn in from the outside, is heated by the heat exchanger, and then flows through the distribution lines into the living room and bedroom. The old, stale air is extracted from the kitchen, and the bathroom you remodeled flows through distribution lines to the heat exchanger, where it gives off the heat and then gets outside. The hallway and stairs function as overflow areas.
These ventilation systems have no noise pollution because they are a central system. The outside air and the exhaust air are filtered so that no pollution is expected here. Maintenance costs are to be taken into account in terms of maintenance (filter) and power consumption. Overall, there are very different systems on the market. The degree of heat recovery can already be well over 85 percent.
A central supply and exhaust air system with heat recovery should be the “first choice” for new buildings. The investment costs are around 8,000 to 15,000 $ for a single-family home.
Decentralized Individual Room Ventilation With Heat Recovery
The ventilation takes place via a single device in the outer wall. The automatic window ventilator with heat recovery is a special model. This is installed above or below the window.
The advantage of the decentralized ventilation system lies in the simple installation. These ventilation units are, therefore, often the first choice in existing buildings.
The ventilation devices can be used specifically for individual rooms (e.g., bathroom). You can dehumidify the air sufficiently, and there are various options for filtering the outside air. The devices are preferably equipped with humidity sensors (and/or with sensors for measuring the CO 2 concentration) so that ventilation is provided as required.
The disadvantage is that there is often no amortization due to heating cost savings and that the noise of the fan can sometimes be a problem, especially in bedrooms.
The investment costs per device are between 1,000 and 2,000 $. Running costs are to be taken into account concerning power consumption and maintenance (filter).…