ᐅ Centralized mechanical ventilation with heat recovery: Are individual rooms controllable?
Created on: 23 Apr 2015 11:59
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LuciferSam
Hello community,
while researching central systems for controlled residential ventilation (controlled ventilation) with heat recovery (heat recovery), I noticed something: nobody seems to build systems where the ventilation of individual rooms can be comfortably adjusted on an ongoing basis (not just once for balancing but continuously, daily). I can neither find testimonials nor see such systems being advertised.
Why do I want this? – A central controlled ventilation system with heat recovery equalizes the temperature of all connected rooms over time. (Air is extracted from all rooms, mixed, passed through the heat exchanger; warmed fresh air reaches every room.) However, this is not always desirable. At night, I want to sleep in a cold room but still use controlled ventilation to be able to sleep with windows and doors closed. The living room, heated by underfloor heating, I do not want or need to cool down every evening. If I could turn off the ventilation in the living room at night and in the bedroom at least temporarily during the day, the problem would be solved.
Would this be difficult? – Air dampers in all pipes from the central manifold to the rooms, controlled by very expensive actuators or simple, inexpensive servos from the model building sector, could regulate the airflow. Sound attenuators would probably be needed behind them (?). Between the fan and the first central manifold, a pressure sensor could be installed to control the fan continuously. If the air pressure before the control dampers is kept constant, adjusting one damper should not significantly affect the airflow through another.
As I see it, this would be a huge advantage with reasonable extra effort. Why does nobody do this? I am still quite a beginner in this field. Have I overlooked something?
Thanks!
while researching central systems for controlled residential ventilation (controlled ventilation) with heat recovery (heat recovery), I noticed something: nobody seems to build systems where the ventilation of individual rooms can be comfortably adjusted on an ongoing basis (not just once for balancing but continuously, daily). I can neither find testimonials nor see such systems being advertised.
Why do I want this? – A central controlled ventilation system with heat recovery equalizes the temperature of all connected rooms over time. (Air is extracted from all rooms, mixed, passed through the heat exchanger; warmed fresh air reaches every room.) However, this is not always desirable. At night, I want to sleep in a cold room but still use controlled ventilation to be able to sleep with windows and doors closed. The living room, heated by underfloor heating, I do not want or need to cool down every evening. If I could turn off the ventilation in the living room at night and in the bedroom at least temporarily during the day, the problem would be solved.
Would this be difficult? – Air dampers in all pipes from the central manifold to the rooms, controlled by very expensive actuators or simple, inexpensive servos from the model building sector, could regulate the airflow. Sound attenuators would probably be needed behind them (?). Between the fan and the first central manifold, a pressure sensor could be installed to control the fan continuously. If the air pressure before the control dampers is kept constant, adjusting one damper should not significantly affect the airflow through another.
As I see it, this would be a huge advantage with reasonable extra effort. Why does nobody do this? I am still quite a beginner in this field. Have I overlooked something?
Thanks!
Your misconception lies in assuming that the air escapes at temperature T1... this is not the case, because due to mixing, the air escapes at temperature T3, which is the result of T1 and T2. Additionally, you did not include the cooling factor for the window/wall/floor in your calculation either.
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LuciferSam27 Apr 2015 10:54That is clear to me, as I also mentioned (This of course only applies as long as the room temperature is around 18°C (64°F). The power output is proportional to the difference T2-T1, so it decreases as the room warms up.).
It is really only about estimating the order of magnitude. If it had turned out that the ventilation system heats with a maximum of 5W–10W, I would have said okay, that is negligible.
However, from experience, I know that whether one or two people sleep in the room is definitely relevant to the temperature development, completely independent of cooling/heating through walls, windows, etc. Therefore, ventilation heating with 30W–60W is also significant.
It is really only about estimating the order of magnitude. If it had turned out that the ventilation system heats with a maximum of 5W–10W, I would have said okay, that is negligible.
However, from experience, I know that whether one or two people sleep in the room is definitely relevant to the temperature development, completely independent of cooling/heating through walls, windows, etc. Therefore, ventilation heating with 30W–60W is also significant.
EveundGerd27 Apr 2015 15:07Wouldn't a decentralized system make more sense for you then?
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FlaT_EriC14 Sep 2022 12:24Hi,
are there any updates on this topic? I have exactly the same thoughts regarding our 1-year-controlled mechanical ventilation system as the original poster and would also really appreciate a dynamically adjustable manifold, ideally controllable via automation nowadays (app, web interface, or similar).
In winter, during evening and night, the air supply from the mechanical ventilation to the living room should be minimized because it cools unnecessarily due to the supply air—which even with heat recovery is below the desired room temperature—and instead increase the supply to the bedrooms where this cooler air would be welcome. During the day, more air could then be supplied to the living areas when the outside temperature is closer to the room temperature.
It should be possible somehow to get a manifold (or accessories for the individual ducts) that can be controlled in this way?!
I’m curious to get this discussion going again...
are there any updates on this topic? I have exactly the same thoughts regarding our 1-year-controlled mechanical ventilation system as the original poster and would also really appreciate a dynamically adjustable manifold, ideally controllable via automation nowadays (app, web interface, or similar).
In winter, during evening and night, the air supply from the mechanical ventilation to the living room should be minimized because it cools unnecessarily due to the supply air—which even with heat recovery is below the desired room temperature—and instead increase the supply to the bedrooms where this cooler air would be welcome. During the day, more air could then be supplied to the living areas when the outside temperature is closer to the room temperature.
It should be possible somehow to get a manifold (or accessories for the individual ducts) that can be controlled in this way?!
I’m curious to get this discussion going again...
When I installed my mechanical ventilation system with ductwork, I fitted a throttle valve before each outlet. Then, I installed continuously adjustable Belimo damper actuators on these valves. This allows me to control each outlet individually. I created various scenarios that can be executed as needed. There are also several sensors for measuring airflow volume, so you can work with specific setpoints for each outlet. This makes it possible to fine-tune the system even better since adjusting one outlet affects all the others. Hopefully, I will get around to doing that sometime.
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FlaT_EriC15 Sep 2022 09:39Not exactly what I expected, but still sounds interesting. Since everything is already finished here, I would only have the option to install something directly at the distribution board. If I understood correctly after looking it up, it definitely seems difficult to connect this to the distribution board. How exactly is this controlled?
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