ᐅ Reliability of an energy calculation for KfW 55 – is it too high?
Created on: 20 Jun 2016 18:01
W
WT1987
Hello everyone,
For our new build with 2 full floors and a basement, we have now received a calculation for the entire KfW application. However, it seems to me that the numbers are being calculated quite high or may even be incorrect.
Some data about the house:
Is that the electricity consumption I should expect, or am I misunderstanding something? That seems very high!
Thank you in advance.
For our new build with 2 full floors and a basement, we have now received a calculation for the entire KfW application. However, it seems to me that the numbers are being calculated quite high or may even be incorrect.
Some data about the house:
- Architect’s plan shows living area: ground floor 75m² (807 ft²) & upper floor 70m² (753 ft²) (difference due to open space)
- Clear ceiling height: ground floor 2.7m (8 ft 10 in) & upper floor 2.5m (8 ft 2 in)
- Basement is unheated, air-water heat pump located in the basement
- Attic is not developed
- Air-water heat pump with ventilation system including heat recovery
- The expert assessor calculates a usable floor area of 277m² (2,982 ft²), which seems very high to me! He then uses this to estimate electricity consumption and arrives at a final energy demand of 4,860 kWh/year
Is that the electricity consumption I should expect, or am I misunderstanding something? That seems very high!
Thank you in advance.
Hello,
I received the KfW calculation today as well.
It is planned to be a KfW55 house with a footprint of 9 by 11 m (29.5 by 36 ft).
The annual primary energy demand for the reference building is given as 76 kWh/m²a, ours is 33.8. That is less than 55% of the reference building, so that seems fine to me.
I don’t understand the transmission heat loss. The reference building shows 0.376, ours 0.249. Shouldn’t this also be less than 55% of the reference building?
Thank you
I received the KfW calculation today as well.
It is planned to be a KfW55 house with a footprint of 9 by 11 m (29.5 by 36 ft).
The annual primary energy demand for the reference building is given as 76 kWh/m²a, ours is 33.8. That is less than 55% of the reference building, so that seems fine to me.
I don’t understand the transmission heat loss. The reference building shows 0.376, ours 0.249. Shouldn’t this also be less than 55% of the reference building?
Thank you