Grym
2016-09-01 00:25:29
- #1
The sentence referred to your above statement that a controlled residential ventilation system can neither cool nor heat. That is logical, as controlled residential ventilation is neither an air conditioner nor a heater. The heat exchanger only tries to transfer as much energy as possible from the extracted air to the incoming air (or vice versa in summer). However, it will never be 100%. In this respect, the air inside the house heats up with each air exchange. Furthermore, every electrical device generates energy. In this respect, controlled residential ventilation is therefore counterproductive in summer as well (unless it is outside the thermal envelope). Therefore, I wonder why energy (electricity) is spent to heat a house when I want it to be cooler.
If it is 23 degrees inside (exhaust air) and 31 degrees outside (outside air), then the supply air comes in at about 24 degrees. With 225 m3 air exchange per hour and a specific heat capacity of air of 0.34 Wh/(m3*K), this results in a heat input (at midday, assuming 31 degrees outside temperature) of: 0.34 Wh/(m3*K) x 225 m3 x 1K per hour = 76.5 W = 0.077 kW So as much as a light bulb... This is of course distributed over all rooms, so more like 1/5 of a light bulb for the living room, for example.
This applies to the warmest hours of the day.
If it is then 17 degrees outside at night and 23 degrees inside and bypass as well as output are increased to 400m3, this results in a cooling capacity of: 0.34 x 400 x 6K per hour = 816 W = 0.816 kW
By the way, a floor cooling system achieves several kW of capacity.