Susiepoos
New Member
Can anyone advise if I can disable or slow down the fans on the Eberspacher Hydronic system in our boat. We have three outlets which are fan assisted and they are extremely noisy at 65 decibels?
Eberspacher hydronic diesel heating
- Thread starter Susiepoos
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longjohnsilver
Well-Known Member
The fans are only there to distribute the heat from the radiator. Therefore I see no reason why you shouldn't be able to turn each fan off individually if you so wish, however the penalty would be less warmth. I guess it might also be possible to have some way of slowing the fan down, but how you'd go about doing that I have no idea.
QBhoy
Well-Known Member
Hi
Pretty sure you can't do both.
What you can do or check is;
Perhaps get shuttable outlets (one must be permanently open though) for areas you are in that perhaps don't need it. The other and probably most suited solution is;
Make sure it is installed properly and is working off the thermostat.
The temp can be set and once up to temp, the fan will slow down and slowly cut in and out to maintain temp. In order to achieve this, the inlet or suction to the heater must be located in the area the heater is aiming to heat....therefore it knows the temperature of the air. This is the way it is designed to be. If it isn't and the suction is sucking from a cold and non heated area....it will most likely constantly run at full power in an attempt to try and reach a never achievable set point (by the controller)
Pretty sure you can't do both.
What you can do or check is;
Perhaps get shuttable outlets (one must be permanently open though) for areas you are in that perhaps don't need it. The other and probably most suited solution is;
Make sure it is installed properly and is working off the thermostat.
The temp can be set and once up to temp, the fan will slow down and slowly cut in and out to maintain temp. In order to achieve this, the inlet or suction to the heater must be located in the area the heater is aiming to heat....therefore it knows the temperature of the air. This is the way it is designed to be. If it isn't and the suction is sucking from a cold and non heated area....it will most likely constantly run at full power in an attempt to try and reach a never achievable set point (by the controller)
longjohnsilver
Well-Known Member
You say one outlet must be permanently open, surely that only applies to warm air heating? This is essentiallly a warm water radiator set up
Susiepoos
New Member
It is running off the thermostat and cutting in and out maintaining the temper but it is shifting a large amount of air.
ip485
Well-Known Member
The fans are purely to inrease the radiators efficiency. Since the radiators are small without some fan assistance they will distribute little heat. With no fans there is a risk the return water will remain too hot which will cause the eber to trip. Some people who use the eber for hot water pump the return through the engine block for exactly this reason.
Not closing a vent is applicable to a hot air eber as already said.
Fitting a rheostat to each fan seems the obvious solution.
Not closing a vent is applicable to a hot air eber as already said.
Fitting a rheostat to each fan seems the obvious solution.
Susiepoos
New Member
Thank you for everyone's help. I will get the marine Electronic people out tomorrow. As it is newly commissioned it is under warranty.
pcatterall
Well-Known Member
I guess that 'under warranty' may not apply in the sense that the heaters are probably working and installed as designed. Rheostats or 3 position switches would be my preferred option but there will be a balance between getting the heat distributed and noise
PaulRainbow
Well-Known Member
This applies to blown air heating, and is wrong anyway. If blown air heating is installed with the intake in the cabin the condensation is colossal. Blown are heaters will achieve the desired cabin temperature with the intake air coming from outside the boat, in the depths of winter.
wilkinsonsails
Well-Known Member
We changed the fans on an old noisy hydronic heat for some computer ones .Almost silent now compared to before .
David2452
Well-Known Member
I've had this with blown air matrix installs a few times, I use a 12v to 6v dropper in the fan power supply so it will even work with multi speed fans, also generally a thermostat on the matrix which will not allow the fans to run until the coolant temperature reaches 50 degrees, no point in stirring up cold air.
David2452
Well-Known Member
Absolutely, but you are assuming a proper marine install, properly specified as to output and with a remote temperature sensor. Far from a safe assumption in my experience.
DipperToo
Well-Known Member
I have a Hydronic and power is only applied to the fans when the boiler senses that the water has started warming up.
Each cabin has a thermostat for the fan and if I remember correctly, the main saloon fan goes into a half speed mode when temperature is reached.
The controls are all Eber.
Each cabin has a thermostat for the fan and if I remember correctly, the main saloon fan goes into a half speed mode when temperature is reached.
The controls are all Eber.
Playtime
Well-Known Member
Most small matrix heaters used with hydronic systems have a 2 speed fan fitted as standard. This requires a 3 position switch (off/low/high) to be wired in for each matrix fan. It would appear that your installer has omitted the necessary switches. I would ask him which matrix heaters he used and why he hasn't included the necessary 3 way switches.
A standard Eberspacher hydronic system comes with the wiring loom already set-up with the water temperature thermostat included in the fan circuit. The fans should therefore not turn on until the water is warm (approx 50C I would say).
I agree that matrix heaters on the high setting (which is presumably how yours are running) are very noisy. I have 4 in my system and someone once remarked that it sounded like a 747 on take-off. However, I find the system very effective for raising the cabin temperature quickly and then the fans (and consequently the noise level) can be reduced. The main advantage of the hydronic system is that water is a much more efficient way of transferring the heat to where it is required than hot air. However, unless you have space for large 'radiators' then fan assisted matrix heaters are necessary for the final distribution of the heat.
A standard Eberspacher hydronic system comes with the wiring loom already set-up with the water temperature thermostat included in the fan circuit. The fans should therefore not turn on until the water is warm (approx 50C I would say).
I agree that matrix heaters on the high setting (which is presumably how yours are running) are very noisy. I have 4 in my system and someone once remarked that it sounded like a 747 on take-off. However, I find the system very effective for raising the cabin temperature quickly and then the fans (and consequently the noise level) can be reduced. The main advantage of the hydronic system is that water is a much more efficient way of transferring the heat to where it is required than hot air. However, unless you have space for large 'radiators' then fan assisted matrix heaters are necessary for the final distribution of the heat.
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PaulRainbow
Well-Known Member
Absolutely, but you are assuming a proper marine install, properly specified as to output and with a remote temperature sensor. Far from a safe assumption in my experience.
Yes, there do seem to be a lot of dodgy setups around.
Ian_Edwards
Well-Known Member
The Hydronic 10 on my boat has 3 matrix heaters, each with 3 outputs.
The matrix heaters are individually controlled by individual Eberspacher thermostats, but they simply switch the single speed fans on and off.
I reduced the fan noise (and improved the efficiency) by insulating the ducting, which had a limited effect.
I mounted the matrix heater on 10mm ply boards and then gluing the boards to some 15mm closed cell fire resistant foam which was then glued to the bulkhead (forming a foam sandwich). So that the boards on which the matrix heater are mounted are acoustically isolated from the bulkhead by the foam. This made the matrix heaters much quieter and they are still in all glued in place 4 years on. I used wall board adhesive.
In addition, where possible, I lined the cavity in which the matrix heater is mounted with the 15mm foam.
The sound insulation made a big difference to the noise level, particularly in the saloon.
I'd be interesting in buying some quiet computer fans to reduce the noise even further, but they would have to be an easy swap and have an equivalent of better air flow. Can anyone recommend a suitable fan?
The matrix heaters are individually controlled by individual Eberspacher thermostats, but they simply switch the single speed fans on and off.
I reduced the fan noise (and improved the efficiency) by insulating the ducting, which had a limited effect.
I mounted the matrix heater on 10mm ply boards and then gluing the boards to some 15mm closed cell fire resistant foam which was then glued to the bulkhead (forming a foam sandwich). So that the boards on which the matrix heater are mounted are acoustically isolated from the bulkhead by the foam. This made the matrix heaters much quieter and they are still in all glued in place 4 years on. I used wall board adhesive.
In addition, where possible, I lined the cavity in which the matrix heater is mounted with the 15mm foam.
The sound insulation made a big difference to the noise level, particularly in the saloon.
I'd be interesting in buying some quiet computer fans to reduce the noise even further, but they would have to be an easy swap and have an equivalent of better air flow. Can anyone recommend a suitable fan?
