ᐅ Does it make sense to install an air conditioning system as a retrofit?
Created on: 25 Mar 2020 18:19
A
andimann
Hello everyone,
We have been living in the house since December 2016, and during the planning and construction phase, I never even considered installing an air conditioning system.
Basically, we manage without one. During the extreme summer of 2018, the upstairs temperature peaked at 25.5-26°C (78-79°F). That was just barely acceptable, but personally, it was borderline for sleeping. Summers like that will probably become more frequent in the future. In summer 2019, temperatures never rose above 25°C (77°F), but unfortunately there were times of very high humidity, which made it uncomfortable. Morning ventilation didn't help much then; it actually made things worse. Ventilation only works effectively if the shutters are open, but we prefer to sleep in the dark...
Since I've learned that air conditioning systems are much more affordable both in initial cost and electricity consumption than I originally thought, I now realize I should have planned for one back then. Hindsight is always 20/20...
Now I'm considering whether it would be possible to retrofit an air conditioner, at least with minimal functionality.
The requirements would be:
We have a stairwell with a half-landing and an adjacent wide hallway upstairs.
The idea is to install an indoor unit in the stairwell, above the window, directly below the upstairs ceiling. From there, the unit could blow air along the hallway and, with doors open to Child 1 / Child 2 and the bedroom, at least some cooled air would reach those rooms. Possibly supported by a oscillating fan placed in the hallway. The system would run in the morning until just after noon, when no one is home anyway. This way, the house would be pre-cooled during that time and wouldn’t keep heating up continuously. As mentioned, the goal is just to lower the temperature by about 2°C (4°F), not to cool all rooms evenly and draft-free down to 18°C (64°F).
The outdoor unit could be placed next to the ledge, and the piping routed straight up in the corner, even though that is on the north side, where our trash bins and firewood are stored. So it’s not exactly the most attractive spot...
Questions (I understand that precise predictions are difficult):
Best regards,
Andreas
We have been living in the house since December 2016, and during the planning and construction phase, I never even considered installing an air conditioning system.
Basically, we manage without one. During the extreme summer of 2018, the upstairs temperature peaked at 25.5-26°C (78-79°F). That was just barely acceptable, but personally, it was borderline for sleeping. Summers like that will probably become more frequent in the future. In summer 2019, temperatures never rose above 25°C (77°F), but unfortunately there were times of very high humidity, which made it uncomfortable. Morning ventilation didn't help much then; it actually made things worse. Ventilation only works effectively if the shutters are open, but we prefer to sleep in the dark...
Since I've learned that air conditioning systems are much more affordable both in initial cost and electricity consumption than I originally thought, I now realize I should have planned for one back then. Hindsight is always 20/20...
Now I'm considering whether it would be possible to retrofit an air conditioner, at least with minimal functionality.
The requirements would be:
- Cooling the air temperature upstairs by a maximum of 2-3°C (4-5°F). Keeping it under 24°C (75°F) would be perfectly fine. We don’t want it colder than that.
- Dehumidification of the air.
We have a stairwell with a half-landing and an adjacent wide hallway upstairs.
The idea is to install an indoor unit in the stairwell, above the window, directly below the upstairs ceiling. From there, the unit could blow air along the hallway and, with doors open to Child 1 / Child 2 and the bedroom, at least some cooled air would reach those rooms. Possibly supported by a oscillating fan placed in the hallway. The system would run in the morning until just after noon, when no one is home anyway. This way, the house would be pre-cooled during that time and wouldn’t keep heating up continuously. As mentioned, the goal is just to lower the temperature by about 2°C (4°F), not to cool all rooms evenly and draft-free down to 18°C (64°F).
The outdoor unit could be placed next to the ledge, and the piping routed straight up in the corner, even though that is on the north side, where our trash bins and firewood are stored. So it’s not exactly the most attractive spot...
Questions (I understand that precise predictions are difficult):
- Would such a setup be effective, or is it a bad idea that would just result in a cold hallway and rooms that are as warm as before? I think I've seen a similar configuration in a thread here, but I can’t find it anymore.
- What cooling capacity should I expect to need? The bedroom, hallway, and both children’s rooms together are about 65 m² (700 sq ft). I’ve seen recommendations between 4 and 6 kW (14,000 to 21,000 BTU), but since we don’t want to cool down to 19°C (66°F), just reduce the temperature slightly, should it be less?
- Are there devices or brands known for having stronger fans? We need a unit that can blow its airflow further...
- How is condensate handled in such a setup? Would we likely need to run another drain hose through the exterior wall?
Best regards,
Andreas
I have looked into this topic a bit myself and also talked to an HVAC specialist.
Your plan probably won’t work as is. We were recommended a split air conditioning system with three indoor units (for the three bedrooms). Personally, I would install ceiling units connected through the attic and mount the outdoor unit on a roof bracket.
However, you need to keep in mind that each unit requires a condensate drain.
We have put our considerations on hold for now, as we want to focus on other projects first.
Your plan probably won’t work as is. We were recommended a split air conditioning system with three indoor units (for the three bedrooms). Personally, I would install ceiling units connected through the attic and mount the outdoor unit on a roof bracket.
However, you need to keep in mind that each unit requires a condensate drain.
We have put our considerations on hold for now, as we want to focus on other projects first.
N
nordanney26 Mar 2020 08:24Please keep in mind that cold air sinks. So it will flow down the stairs while the warm air from the ground floor rises. I assume that Child 1/2 will not benefit at all from the air conditioning with your current plan. RFR has already mentioned something similar.
Hello,
thank you for the reply. The "proper" solution would be 3-4 indoor units, that’s clear. However, I want to avoid the effort, and especially the condensate drainage for the distributed indoor units would be challenging. That leads to using units with integrated pumps and all that kind of stuff. I would also prefer to avoid drilling through the upper floor ceiling. We have a concrete ceiling there, and making larger openings is not something you can just do easily.
I will probably consult local HVAC professionals soon.
Best regards,
Andreas
thank you for the reply. The "proper" solution would be 3-4 indoor units, that’s clear. However, I want to avoid the effort, and especially the condensate drainage for the distributed indoor units would be challenging. That leads to using units with integrated pumps and all that kind of stuff. I would also prefer to avoid drilling through the upper floor ceiling. We have a concrete ceiling there, and making larger openings is not something you can just do easily.
I will probably consult local HVAC professionals soon.
Best regards,
Andreas
I really have no idea about this topic, but couldn’t the same effect be achieved with portable devices in the bedrooms? After all, they are only needed on a few days throughout the year. And outside of the peak summer season, the devices could be stored elsewhere. Or am I oversimplifying things? Or are the portable devices not effective?
Of course, the best option would be to install them during the house construction phase, but maybe as a simple retrofit solution.
Of course, the best option would be to install them during the house construction phase, but maybe as a simple retrofit solution.
Portable units are not very efficient. For the better ones, you still have to regularly add water. They are also noisier.
The biggest issue is the exhaust air. You either have the unattractive and inefficient option of tilted doors and windows with sealing tape... or you go for a wall penetration. At that point, the cost is not much different from a solid solution.
Single-block units are acceptable for apartments where you cannot or are not allowed to make modifications. We used them ourselves last summer in our attic apartment.
The biggest issue is the exhaust air. You either have the unattractive and inefficient option of tilted doors and windows with sealing tape... or you go for a wall penetration. At that point, the cost is not much different from a solid solution.
Single-block units are acceptable for apartments where you cannot or are not allowed to make modifications. We used them ourselves last summer in our attic apartment.
Similar topics