ᐅ Heating Savings: Is up to 95% Heat Recovery Realistically Achievable?
Created on: 25 Feb 2018 20:52
A
Aliban2014
Good evening dear forum members,
We are considering installing a (central) mechanical ventilation system with heat recovery in our new build.
During my research on this topic, I keep coming across the claim:
“...up to 90%-95% heat recovery, resulting in heating energy savings.”
However, I am having trouble fully understanding this.
My understanding of a controlled ventilation system with heat recovery is that it works by retaining as much generated heat as possible (up to 90-95%) inside the building. The warm indoor air is mixed with the colder (winter) / warmer (summer) outdoor air and then brought back inside.
This “heating energy saving” only applies to the winter period, when you would otherwise ventilate by fully opening windows for a short time, correct?
Is it even possible to calculate how much energy you save? I imagine it is quite minimal if you only ventilate twice a day for 5-10 minutes, for example. Also, it is not guaranteed that you actually achieve 90-95% heat recovery, right?
We will not base our decision solely on this, but I am just curious whether it is realistically possible to make such a calculation in advance with certain assumptions or if anyone has practical experience with this?
Best regards
We are considering installing a (central) mechanical ventilation system with heat recovery in our new build.
During my research on this topic, I keep coming across the claim:
“...up to 90%-95% heat recovery, resulting in heating energy savings.”
However, I am having trouble fully understanding this.
My understanding of a controlled ventilation system with heat recovery is that it works by retaining as much generated heat as possible (up to 90-95%) inside the building. The warm indoor air is mixed with the colder (winter) / warmer (summer) outdoor air and then brought back inside.
This “heating energy saving” only applies to the winter period, when you would otherwise ventilate by fully opening windows for a short time, correct?
Is it even possible to calculate how much energy you save? I imagine it is quite minimal if you only ventilate twice a day for 5-10 minutes, for example. Also, it is not guaranteed that you actually achieve 90-95% heat recovery, right?
We will not base our decision solely on this, but I am just curious whether it is realistically possible to make such a calculation in advance with certain assumptions or if anyone has practical experience with this?
Best regards
K
Knallkörper26 Feb 2018 19:51If the question is: "Is it possible to calculate the efficiency (more precisely the heat recovery rate) of a heat exchanger?" then I would say: yes, it is possible. However, you will never get 90% efficiency, but at most 80%, and that likely only with low volume flow rates and suitable designs.
