PassivHaus

Goals

  1. < 15 kWh/m2.yr Heating Consumption,
  2. < 15 kWh/m2.yr Cooling Consumption,
  3. < 10 W/m2 Heat Load,
  4. < 120 kWh/m2.yr Primary Energy Consumption,
  5. < 0.6ACH @ 50Pa pressure difference

 

Envelope

  1. Glazing <0.6u,
  2. Windows/Doors <0.8u,
  3. Walls <0.15u,
  4. Roof <0.15u,
  5. External Floor <0.15u

 

Recommendations*

  1. Ventilation HR >75% efficient @ 0.45 Wh/m3,
  2. Thermal bridging free constant 0.01 W/mK,
  3. <10% of occupied hours see temperatures above 25oC,
  4. 30m3 per person per hour fresh air

*vary depending on location

 

Sefaira Setup

Envelope Parameters:

Variable

Sefaira Value

Roof U-Value (W/m2 C)

0.15

Wall U-Value (W/m2 C)

0.15

Floor U-Value (W/m2 C)

0.15

Glazing U-Value (W/m2 C)

0.8

Glazing SHGC

0.4**

Leakage (m3/m2.h)

1.4

** there are no specifications for SHGC in PassivHaus so this is indicative only

 

HVAC Parameters: 

Parameter

Sefaira Value

Heating Efficiency

0.91

Cooling Efficiency

3

Ventilation Rate (L/m2.s)

(8.3l/s*number of occupants)/floor area in m2

 

Ventilation Rate 

A Ventilation rate example could be;

  • 3 people,
  • 500m2 internal area,
  • 30m3 per person per hour
  • What is ventilation rate in l/m2.s?

30,000l/3600secs.p = 8.3l/s.p

8.3l/s.p * 3p = ~25l/s

25l/s / 500m2 = 0.05 l/m2.s

So, in Sefaira, for this PassivHaus project 0.05l/m2.s is the desired ventilation rate.

 

MVHR

For MVHR in Sefaira Architecture see this article

Was this article helpful?
0 out of 1 found this helpful

Comments

  • Avatar
    David Posada

    It would be so appreciated if you could provide a version of this article for the poor souls who had the misfortune of birth in an under-developed region that never adopted the global standard of SI units.