Decision Controlled Residential Ventilation: Helios EC 300 W R vs. HomeVent comfort FR 301

Phew, regarding the living area. It is already clear that both systems are undersized. I would not go below 350, rather up to 400 (regardless of the manufacturer).

Thanks for the reply! Unfortunately, this does not correspond with my research. The applicable guideline is DIN 1946-6. This defines various room airflows, whereby the controlled residential ventilation must achieve the nominal ventilation.

Moisture protection = fWS * (-0.001 * Ane² + 1.15 * Ane + 20)
Nominal ventilation = -0.001 * Ane² + 1.15 * Ane + 20
Reduced ventilation = 0.7 * (-0.001 * Ane² + 1.15 * Ane + 20)
Intensive ventilation = 1.15 * (-0.001 * Ane² + 1.15 * Ane + 20)

where Ane = area of the usage unit
and fWS = factor to consider thermal insulation (0.3 for new/renovated buildings, 0.4 for all others)

This would result for our house (rounded up) in:

Moisture protection = 0.3 * (-0.001 * 183² + 1.15 * 183 + 20) = 60 cbm / h
Nominal ventilation = -0.001 * 183² + 1.15 * 183 + 20 = 197 cbm / h
Reduced ventilation = 0.7 * (-0.001 * 183² + 1.15 * 183 + 20) = 138 cbm / h
Intensive ventilation = 1.15 * (-0.001 * 183² + 1.15 * 183 + 20) = 227 cbm / h

The Helios can do 315 cbm per hour, the Hoval 300 cbm. Both should therefore be sufficiently sized according to the DIN specification.

We will address the issue again with the heating engineer – he must have had a reason for it, or his offer is based on similar calculations as shown above.

You are assuming the ideal case. But that is rarely the case. It is true that the systems are sufficient. However, the DIN only specifies the minimum values. So you have little or no room for improvement. Which, conversely, means the system will repeatedly operate at its performance limit, including increased power consumption, noise development, etc. But it’s your house, you can install whatever you want, I don't care.

I am aware that "up to" or "max" represents the ideal case, which is hardly ever, if at all, achieved.

Compared to the specified value of the intensive ventilation level, which is the highest possible, the system would still have about a 1/3 performance buffer - that should be sufficient. And the fact that no or little air should go upwards is also not clear to me from your statement. Isn't it rather the case that one consciously decides not to run the ventilation systems at full level because a) it consumes less electricity and b) too much airflow eventually becomes unpleasant and is perceived as a "draft"?

Don't get me wrong, I am really grateful for your feedback. But I have to check whether the offered device is sufficient - and that ultimately seems to be the case.

More is not necessarily always better, sometimes just more expensive, but not really necessary...

Here you can see live and in color what happens when systems are only designed to cover the minimum requirement. Normal ventilation at about 70%, already relatively loud, yet apparently still insufficient, as a feeling of stale air is still present.

We will ignore the probably missing telephone silencers for now. These would now increase the pressure in the ducts even further, which would result in the system becoming even louder.

Hello Don Mikele!

Have you decided on a device by now? I am currently facing almost the same question. The data of the buildings are also almost identical.

Best regards
Mathias

We have a Helios controlled residential ventilation EC 500 W ET in a 160sqm house. Most of the time you can run it so that it is not audible, but it can also quickly exchange all the air. I would not have chosen a 300, especially not for a 180sqm house.