ErP Ecodesign for RVUs CASE STUDY

I t is not just about efficiency

CASE STUDY | ECODESIGN RVUs

+ other benefits:

The heat exchanger is very important part of the calculation.

There are two main parameters of the heat exchanger:

Efficiency combined with balanced pressure drop. Both

parameters are important. Pressure drop even more.

Why?

Case: Residential unit RVU 250

New legislation, ErP VU 1235/2014 Ecodesign for residential units (RVUs) brings ranking of these

units into the energy class according to the SEC calculation.

In the first RVU 250, there is used RSP+10 plastic counter flow heat exchanger with spacing 3.2 mm (81.5 %/70 Pa). In the second one, there is the Competitor plastic counter flow heat exchanger with lower spacing (83.3 %/115 Pa).

• In some cases smaller fans can be used or higher static pressure is available• Larger spacing means approx. 10 % less used pre-heating power• Lower risk of freezing• Higher year efficiency (depends on climatite used)• Easier condensate drain

Conclusion: In this case the � rst RVU 250 with the lower e� ciency heat exchanger achieves the noise level lower by -1 dB (A) compared to the second one and slightly better SEC level (If this would be on the edge between two classes this can decide).

RVU with Competitor´s HEXRVU with RSP+10...-32

[m3/h]

0 50 100 150 200 250 300

RVU 250 – characteristic with di� erent heat exchangers

Stat

ic p

ress

ure

avai

labl

e [P

a]

200

100

400

500

300

0

[m3/h]

0 50 100 150 200 250 300

RVU 250 – consumption with di� erent heat exchangers

[W]

40

20

80

100

120

140

60

0

AV = 200 m3/hLWA = 35 dB(A)P = 92 WEff. = 81.5 %SEC = -38.64 kWh/(m2a) *A

AV = 200 m3/hLWA = 36 dB(A)P = 108 WEff. = 83.3 %SEC = -37.95 kWh/(m2a) *A

RSP+10-300-32

Competitor´s HEX

PRE-10 %