Hello,
I currently have a heat pump, Nibe Fighter 1235 from 2010, with an associated ground-loop heat exchanger installed. I ventilate using Pax 201 fans (4W, theoretical airflow 95m3/h) in 3 wet areas distributed over 2 bathrooms and 1 laundry room. These pax fans run around the clock.
In connection with renovating one of the bathrooms, I initially thought about skipping the pax fan and instead installing an insulated duct fan in the attic (single-story house) to be able to share it and also ventilate a closet (4m2) and a cabinet where the home theater system will be placed.
The thought crossed my mind whether I should instead install a Nibe FLM 30 to the heat pump.
Roughly estimated, I need about 15 meters of ducting from one bathroom (which is wall-to-wall with the closet and home theater cabinet) in the attic. And approximately 7 meters from bathroom number 2. The boiler is in the laundry room, so that ducting will be from the existing exhaust vent about 2 meters. I plan to use insulated spiral ducts with cleaning hatches and as few angles as possible. A silencer should probably also be installed (I was planning on having it if it becomes the duct fan project instead).
I would appreciate it if someone knowledgeable (no know-it-alls, please, in this thread) could calculate the potential payoff time for the additional cost of an FLM versus a duct fan.
I found a NIBE FLM 30 for 10900 including VAT online, the duct fan costs 2600 kronor. We can exclude the cost of labor and ducting. What is interesting is whether the FLM can recover its additional purchase cost compared to ventilating out 21-degree air.
Thanks in advance
I currently have a heat pump, Nibe Fighter 1235 from 2010, with an associated ground-loop heat exchanger installed. I ventilate using Pax 201 fans (4W, theoretical airflow 95m3/h) in 3 wet areas distributed over 2 bathrooms and 1 laundry room. These pax fans run around the clock.
In connection with renovating one of the bathrooms, I initially thought about skipping the pax fan and instead installing an insulated duct fan in the attic (single-story house) to be able to share it and also ventilate a closet (4m2) and a cabinet where the home theater system will be placed.
The thought crossed my mind whether I should instead install a Nibe FLM 30 to the heat pump.
Roughly estimated, I need about 15 meters of ducting from one bathroom (which is wall-to-wall with the closet and home theater cabinet) in the attic. And approximately 7 meters from bathroom number 2. The boiler is in the laundry room, so that ducting will be from the existing exhaust vent about 2 meters. I plan to use insulated spiral ducts with cleaning hatches and as few angles as possible. A silencer should probably also be installed (I was planning on having it if it becomes the duct fan project instead).
I would appreciate it if someone knowledgeable (no know-it-alls, please, in this thread) could calculate the potential payoff time for the additional cost of an FLM versus a duct fan.
I found a NIBE FLM 30 for 10900 including VAT online, the duct fan costs 2600 kronor. We can exclude the cost of labor and ducting. What is interesting is whether the FLM can recover its additional purchase cost compared to ventilating out 21-degree air.
Thanks in advance
If the theoretical flow of 95m3 per hour is also the actual, it is a suitable flow to ventilate a living area of 75m2. (Boverket's 35l/s per sqm).
But in any case, I believe you can roughly recover something between 5 and 20 kWh per day, i.e., approximately 5-20:- per day.
It is difficult to know the actual airflow, and I also do not know what efficiency that exhaust module has and how low the exhaust air temperature can be.
And now I realized that these calculations were as if it concerned an exhaust air heat pump, sort of. In this case, you already have a certain COP due to geothermal energy, so perhaps it cannot be calculated this way...
But in any case, I believe you can roughly recover something between 5 and 20 kWh per day, i.e., approximately 5-20:- per day.
It is difficult to know the actual airflow, and I also do not know what efficiency that exhaust module has and how low the exhaust air temperature can be.
And now I realized that these calculations were as if it concerned an exhaust air heat pump, sort of. In this case, you already have a certain COP due to geothermal energy, so perhaps it cannot be calculated this way...
Have you used any energy calculation programs? For example http://www.energiberakning.se/ or http://www.rockwool.se/beräkningsprogram/energiprogram? There you can enter your specific data and make comparisons.