ᐅ Specialized ventilation systems needed for older buildings
Created on: 23 Feb 2018 06:42
D
derMartin
Hello,
I have an old building and will be replacing old windows (almost 50% are 68 years old) and possibly upgrading the very poor insulation. In my view, this means making my house more airtight. Inside, there has been noticeable drafts during strong winds even with closed windows and slightly open doors. Since this natural air exchange will be reduced, I am considering a controlled ventilation system with heat recovery. Ventilation in every room is not an option due to the extensive installation work required. The interior of the house has already been fully renovated. A central ventilation system is likely not feasible for the same reasons. Now I am trying to find out if I can manage with a few small, decentralized units. Certain features would be important since I would like to operate a single system across multiple rooms (cost/space/effort).
Kitchen/Bathroom 1: Both are next to each other and important for ventilation. Here I would prefer a system with a humidity sensor that serves both rooms. The tricky part is that it would need to switch to, or I would need to be able to switch to, the room that is currently more humid. If I simply connect both rooms in parallel through ducting, the airflow in the damp room is reduced by half and the supply and exhaust air is not evenly balanced in each room. This means one room is exhausted more and the other receives more air supply. This creates positive pressure and pushes air from one room into the house. If this is the damp room, moisture and possibly odors are pushed into the house.
Living room/bedroom or living room/basement: Here we have a cold room combined with a very warm room. I would need a 2-room ventilation system with separate heat exchangers or one that can heat the air to different degrees. So, a larger device. Especially for the basement, we want a ventilation system because we plan to use it occasionally as living space and in winter for drying clothes, etc. However, it is poorly insulated and therefore quite cold. The bedroom situation is similar but less extreme. We could combine two rooms here, but I don’t want to cool the living room with air from the cold bedroom or fail to heat the bedroom properly.
Smart ventilation with heat recovery: Temperature is an important issue. In winter, it’s about warmth and heating costs. Unfortunately, our installer severely undersized the heating system. I have requested larger radiators, but it still isn’t quite enough. Summer temperatures get very high. Are there ventilation systems that can be set for a preference of cooler or warmer air and then operate accordingly? Of course, heat recovery always helps. What I mean is that during hot summer days there is less heat exchange, and when the unit detects cooler outdoor temperatures, it works harder to cool the room.
Decentralized ventilation with heat recovery and a small air conditioning unit: This would be the next step. Do such combinations exist?
I hope you can help me and that I won’t get answers like “google it” or “use the search function”… ;-) Of course, I’ve already researched, but I haven’t found these specific things. I just thought of the air conditioning aspect now and haven’t searched for that yet.
Thanks in advance,
Best regards
derMartin
I have an old building and will be replacing old windows (almost 50% are 68 years old) and possibly upgrading the very poor insulation. In my view, this means making my house more airtight. Inside, there has been noticeable drafts during strong winds even with closed windows and slightly open doors. Since this natural air exchange will be reduced, I am considering a controlled ventilation system with heat recovery. Ventilation in every room is not an option due to the extensive installation work required. The interior of the house has already been fully renovated. A central ventilation system is likely not feasible for the same reasons. Now I am trying to find out if I can manage with a few small, decentralized units. Certain features would be important since I would like to operate a single system across multiple rooms (cost/space/effort).
Kitchen/Bathroom 1: Both are next to each other and important for ventilation. Here I would prefer a system with a humidity sensor that serves both rooms. The tricky part is that it would need to switch to, or I would need to be able to switch to, the room that is currently more humid. If I simply connect both rooms in parallel through ducting, the airflow in the damp room is reduced by half and the supply and exhaust air is not evenly balanced in each room. This means one room is exhausted more and the other receives more air supply. This creates positive pressure and pushes air from one room into the house. If this is the damp room, moisture and possibly odors are pushed into the house.
Living room/bedroom or living room/basement: Here we have a cold room combined with a very warm room. I would need a 2-room ventilation system with separate heat exchangers or one that can heat the air to different degrees. So, a larger device. Especially for the basement, we want a ventilation system because we plan to use it occasionally as living space and in winter for drying clothes, etc. However, it is poorly insulated and therefore quite cold. The bedroom situation is similar but less extreme. We could combine two rooms here, but I don’t want to cool the living room with air from the cold bedroom or fail to heat the bedroom properly.
Smart ventilation with heat recovery: Temperature is an important issue. In winter, it’s about warmth and heating costs. Unfortunately, our installer severely undersized the heating system. I have requested larger radiators, but it still isn’t quite enough. Summer temperatures get very high. Are there ventilation systems that can be set for a preference of cooler or warmer air and then operate accordingly? Of course, heat recovery always helps. What I mean is that during hot summer days there is less heat exchange, and when the unit detects cooler outdoor temperatures, it works harder to cool the room.
Decentralized ventilation with heat recovery and a small air conditioning unit: This would be the next step. Do such combinations exist?
I hope you can help me and that I won’t get answers like “google it” or “use the search function”… ;-) Of course, I’ve already researched, but I haven’t found these specific things. I just thought of the air conditioning aspect now and haven’t searched for that yet.
Thanks in advance,
Best regards
derMartin
D
derMartin4 Mar 2018 18:13Thanks dertill and Mycraft for the answers.
Separate heat circuits: OK. It somehow makes sense that it doesn’t really make sense since ventilation systems are basically just a heat exchanger with a fan. You wouldn’t save anything by using just one system.
Smart system. Well, the word "smart" might be a bit exaggerated. There are ventilation systems controlled by humidity and CO2 levels. I saw that offered by one manufacturer if you buy the additional circuit boards. Now I just need an outdoor thermometer and a mode that, for example, increases ventilation as soon as the temperature drops below 25°C (77°F) in summer. Maybe also a mode to ventilate heavily at >20°C (68°F) in winter. It’s basically an IF THEN scenario and not really intelligence ;-). I would also love a quick ventilation function. It seems central systems have that, but I haven’t seen it in decentralized units.
Switching air outlets: Here, in the simplest version, I mean one (or two) pipes that can be closed via a switch. Intake always from the same room, and the exhaust air either blows into the neighboring room or directly back into the same room. This doesn’t necessarily have to come from the ventilation system. It could also be a pipe with a flap. I think I will see if something like this could work. My parents have a mechanical ventilation flap. A second system would be massively over the top. It doesn’t have to be 100% airtight.
Thanks and best regards,
gotta go, maybe write something about the basement later.
Separate heat circuits: OK. It somehow makes sense that it doesn’t really make sense since ventilation systems are basically just a heat exchanger with a fan. You wouldn’t save anything by using just one system.
Smart system. Well, the word "smart" might be a bit exaggerated. There are ventilation systems controlled by humidity and CO2 levels. I saw that offered by one manufacturer if you buy the additional circuit boards. Now I just need an outdoor thermometer and a mode that, for example, increases ventilation as soon as the temperature drops below 25°C (77°F) in summer. Maybe also a mode to ventilate heavily at >20°C (68°F) in winter. It’s basically an IF THEN scenario and not really intelligence ;-). I would also love a quick ventilation function. It seems central systems have that, but I haven’t seen it in decentralized units.
Switching air outlets: Here, in the simplest version, I mean one (or two) pipes that can be closed via a switch. Intake always from the same room, and the exhaust air either blows into the neighboring room or directly back into the same room. This doesn’t necessarily have to come from the ventilation system. It could also be a pipe with a flap. I think I will see if something like this could work. My parents have a mechanical ventilation flap. A second system would be massively over the top. It doesn’t have to be 100% airtight.
Thanks and best regards,
gotta go, maybe write something about the basement later.