ᐅ Integrated unit Stiebel Eltron LWZ 504 with central supply air system
Created on: 19 Oct 2014 20:20
D
DJCOON
Hello dear forum members,
Through a variety of professional magazines I ordered for our new build in spring 2015, I came across the air-to-water heat pump LWZ 504 from Stibel Eltron. According to Stibel, this unit offers the following:
"The compact LWZ 504 provides all the comfort expected from an energy-efficient house. The system draws energy for pleasant indoor temperatures and hot water from the outside air. Modern ventilation management ensures that the heat stays inside the building. It recovers up to 90% of the heat from the exhaust air. This allows a comfortable, healthy atmosphere to be combined with high efficiency. The demand-controlled inverter technology also ensures high efficiency. It produces exactly the amount of heat currently needed. High performance values can be achieved even at low temperatures. Energy-saving operation is supported by the modern high-efficiency heating circulation pump and excellent insulation of the hot water storage tank. For those who want to be even more independent from rising energy costs, the LWZ 504 can be operated with self-generated photovoltaic electricity using the appropriate accessories (ISG + SEE). The large, intuitive matrix display ensures that the modern technology in the award-winning design is easy to operate."
Key Features
I understand that this great system naturally comes at a price, but I would like to ask the experts among you—air-to-water heat pump owners as well as heating engineers—for advice or experience with such units. Ideally, it would be great if someone already has this exact pump installed in their basement :-)
Thank you in advance for your responses.
Best regards,
Martin
Through a variety of professional magazines I ordered for our new build in spring 2015, I came across the air-to-water heat pump LWZ 504 from Stibel Eltron. According to Stibel, this unit offers the following:
"The compact LWZ 504 provides all the comfort expected from an energy-efficient house. The system draws energy for pleasant indoor temperatures and hot water from the outside air. Modern ventilation management ensures that the heat stays inside the building. It recovers up to 90% of the heat from the exhaust air. This allows a comfortable, healthy atmosphere to be combined with high efficiency. The demand-controlled inverter technology also ensures high efficiency. It produces exactly the amount of heat currently needed. High performance values can be achieved even at low temperatures. Energy-saving operation is supported by the modern high-efficiency heating circulation pump and excellent insulation of the hot water storage tank. For those who want to be even more independent from rising energy costs, the LWZ 504 can be operated with self-generated photovoltaic electricity using the appropriate accessories (ISG + SEE). The large, intuitive matrix display ensures that the modern technology in the award-winning design is easy to operate."
Key Features
- Excellent suitability for new buildings
- Energy-saving inverter technology
- Ventilation with up to 90% heat recovery
- High domestic hot water comfort with well-insulated 235-liter (62 gallon) storage tank
- Compatible with solar systems
- Stable, sound-optimized housing construction
- Built-in high-efficiency heating circulation pump
I understand that this great system naturally comes at a price, but I would like to ask the experts among you—air-to-water heat pump owners as well as heating engineers—for advice or experience with such units. Ideally, it would be great if someone already has this exact pump installed in their basement :-)
Thank you in advance for your responses.
Best regards,
Martin
We also have a THZ504 in and around the basement. Next week, we will start the drying program for our screed. We chose this capacity. The house has a living area of 160m2 (1,722 sq ft), KfW55 standard. Since we live at about 950m (3,117 ft) above sea level, there is often snow here.
Our builder only installs THZ units with ventilation inside the house.
Our builder only installs THZ units with ventilation inside the house.
For our KfW55 house, I am also planning to install this system. Can anyone tell me how much more expensive the combined unit is overall, compared to getting heating and ventilation separately from Zehnder (ventilation system) and Viessmann (air-to-water heat pump)? Unfortunately, I can't yet assess the price difference.
So, guys, I’m not planning anymore, and I’m not quoting brochures or guessing—I have xx square meters (xx square feet) of living space, etc.
I have the LWZ504!
- The living space doesn’t matter; the total volume of the house counts because all the air in every room is circulated.
- Currently, I’m disappointed with the LWZ504:
1. Ventilation is OK. House volume is about 650 m³ (23,000 cubic feet) (145 m² living space (1,560 square feet)) (Levels 1: 150 m³/h (90 cfm), 2: 170 m³/h (100 cfm), 3: 240 m³/h (140 cfm)).
Noise starts at 180 m³/h (110 cfm) – this comes from the air distributor – but it’s acceptable since this high airflow is only needed for party mode, and the background noise of guests is louder than the system anyway.
2. Heating performance OK
3. Hot water OK
4. Noise next to the unit OK (it’s located in the basement – door to the house is closed)
5. Noise through the duct system – especially during hot water/heating demand – is partially unacceptable!
Well, a city dweller or someone with hearing difficulties might not hear it, but here in the countryside, it’s very unpleasant!
During the day, you might tolerate it because ambient noises are higher anyway. In the evening and at night, I am disappointed.
Once the unit starts rumbling, quiet is over!
Discuss this with your heating installer and Stiebel customer service…
Yes, in summer you pull in hot air, so it’s the summer cassette and ventilation off during the day.
In the transitional seasons, when you have several guests, the room heats up strongly from the heat recovery of the exhaust air (without heating). Opening windows briefly for ventilation is unfortunately essential! (You also easily get flying pests inside this way.)
I imagine a separate system for ventilation and hot water production would avoid this noise disturbance inside the house!
In winter, when neighbors heat with fossil fuels or solid fuels, you draw in exhaust gases at ground level directly and effectively smoke yourself out.
There is a lack of detection for intake air quality here…
I have the LWZ504!
- The living space doesn’t matter; the total volume of the house counts because all the air in every room is circulated.
- Currently, I’m disappointed with the LWZ504:
1. Ventilation is OK. House volume is about 650 m³ (23,000 cubic feet) (145 m² living space (1,560 square feet)) (Levels 1: 150 m³/h (90 cfm), 2: 170 m³/h (100 cfm), 3: 240 m³/h (140 cfm)).
Noise starts at 180 m³/h (110 cfm) – this comes from the air distributor – but it’s acceptable since this high airflow is only needed for party mode, and the background noise of guests is louder than the system anyway.
2. Heating performance OK
3. Hot water OK
4. Noise next to the unit OK (it’s located in the basement – door to the house is closed)
5. Noise through the duct system – especially during hot water/heating demand – is partially unacceptable!
Well, a city dweller or someone with hearing difficulties might not hear it, but here in the countryside, it’s very unpleasant!
During the day, you might tolerate it because ambient noises are higher anyway. In the evening and at night, I am disappointed.
Once the unit starts rumbling, quiet is over!
Discuss this with your heating installer and Stiebel customer service…
Yes, in summer you pull in hot air, so it’s the summer cassette and ventilation off during the day.
In the transitional seasons, when you have several guests, the room heats up strongly from the heat recovery of the exhaust air (without heating). Opening windows briefly for ventilation is unfortunately essential! (You also easily get flying pests inside this way.)
I imagine a separate system for ventilation and hot water production would avoid this noise disturbance inside the house!
In winter, when neighbors heat with fossil fuels or solid fuels, you draw in exhaust gases at ground level directly and effectively smoke yourself out.
There is a lack of detection for intake air quality here…
@Jimly
That sounds bad. Apparently, it’s an issue with the whole-unit system, causing vibrations and noise to be transmitted through the entire ductwork.
However, I find the unit’s sizing surprising. A standard air exchange rate for your building volume is already above setting 3. The unit is running at its limit and is consequently quite loud.
Activated carbon filters help against odors from outside. Also, a note to the neighbor about proper chimney operation might be useful.
That sounds bad. Apparently, it’s an issue with the whole-unit system, causing vibrations and noise to be transmitted through the entire ductwork.
However, I find the unit’s sizing surprising. A standard air exchange rate for your building volume is already above setting 3. The unit is running at its limit and is consequently quite loud.
Activated carbon filters help against odors from outside. Also, a note to the neighbor about proper chimney operation might be useful.
Hello!
We have now moved in and have the same model THZ504.
Stage 1 is 170m³/h (100 cfm)
Stage 2 is 230m³/h (135 cfm)
Stage 3 is 310m³/h (183 cfm)
At stage 1, you can’t hear anything.
At stage 2, you can hear a “rustling” sound in the bathroom, which is where the exhaust air is. In the house, we have 4 exhaust vents and 10 supply air vents.
Between the THZ and the ventilation system, there is a large silencer, actually 2, one for supply and one for exhaust air.
When the unit is running, for example during hot water preparation, we don’t hear anything inside the house. The unit is located in the (concrete) basement.
We have now moved in and have the same model THZ504.
Stage 1 is 170m³/h (100 cfm)
Stage 2 is 230m³/h (135 cfm)
Stage 3 is 310m³/h (183 cfm)
At stage 1, you can’t hear anything.
At stage 2, you can hear a “rustling” sound in the bathroom, which is where the exhaust air is. In the house, we have 4 exhaust vents and 10 supply air vents.
Between the THZ and the ventilation system, there is a large silencer, actually 2, one for supply and one for exhaust air.
When the unit is running, for example during hot water preparation, we don’t hear anything inside the house. The unit is located in the (concrete) basement.
blackm88 schrieb:
a large sound attenuator or two units, one for supply and one for exhaust air. When the system is running, for example during hot water preparation, we don’t hear anything inside the house. The unit is located in the (concrete) basement. The issue might be with the sound attenuators – are they too small? We hear the same noise during normal ventilation as blackm88 described. When heating or similar operations are running, you can hear a bit more. It is very faint but not disturbing for us. It is already very quiet here at night.
The problem with odors coming from outside is actually common among all the people we know with mechanical ventilation with heat recovery systems. Unfortunately, none of the installed units monitor air quality. There is a box from Stiebel where you can insert activated carbon filters. The model is something like LWF FBF 160. Alternatively, for example, @Mycraft has implemented an air quality sensor via KNX combined with a standard mechanical ventilation unit and switches the system off accordingly.
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