The document details the design and construction of the first Passivhaus archive in the UK, located in Hereford, which was presented at the 20th International Passivhaus Conference. It outlines aspects including architectural strategies, energy use, temperature and humidity controls, and troubleshooting during the project. Key lessons learned emphasize the importance of reducing ventilation and dehumidification loads to simplify control strategies for the building's climate management.

1. The first Passivhaus Archive in the UK
HARC Hereford
Presented at:
The 20th International Passivhaus Conference Darmstadt
AECB Annual Conference Norwich July 2016
Nick Grant
Alan Clarke
Elemental Solutions
@ecominimalnick
@AR_Clarke

2. Architect: Architype Ltd, Contractor: Kier Construction,M&E Consultants:E3, Cost Consultants:Arcadis,Energy & Environment:Alan
Clarke and Nick Grant, Structural Engineers:Eastwood and Partners, Certifier:WARM, Client:Herefordshire Council.
Image Nick Grant

3. Datum40.00
50.97
50.97
d ashe
dline ind icates
p ossibil
ee xten sionto
r epository
EPDM Single ply roof
Single ply roof
Ground Floor Signed Fire Exit
Clear footpath from building to muster point
- minimum 1800mm from building
& 1050mm wide
M M
M Fire assembly point
Fire engine access & turning zone
Fire management plan to include provision
for egress through secure gates
Disaster recovery acces
(all floors)
45000
45000
45000
45000
Drawn by
Scale
Dwg no.
Dwg Title
Client
Project
Revision
Checked by
Date
@ A1
Check this drawing is the latest revision.
Do not scale from this drawing.
Do not use the information on this drawing without checking all dimensions on
site.
Do not use any areas indicated for either valuation, puchase, sale or any other
form of legally binding contract.
Do not reproduce any part of this drawing withour prior written consent.
Notes
4
1 : 200
Herefordshire Archive & Records Centre
Herefordshire Council
Site Fire Strategy Plan
GA020
02 Jul 12
MBTMc
6920
CONSTRUCTION
Revision Schedule
Rev Date Description Drawn Checked
1 28 Sep 12 Stage E issue NA MB
2 22 Apr 13 VE issue NA MB
3 09 Aug 13 Issued for Stage F RE MB
4 04 Mar 14 General amendments to bring in line with recommended VE
proposal
LM MB
14 - 20 temp
40-60 RH
18-25 temp
Many considerations:
Security
Fire
Logistics
Quarantine
Daylight
Public access, attractive
Multifunction
Future expansion
etc etcetc . . .
Photo store:
12°C
30% RH
I will just consider
temperature and RH!
Repository:
13-20°C
35-60% RH
Image Architype

4. Easily isolated zones
0 Ground Floor
0
1 First Floor
4590
1
2 Second Floor
8330
2 3 4 5 6 7 8 9
3 Office roof
8715
Parapet
13445
Lower External
Ground level
-170
Level 11
10138
1
DD235
Top of foundation
-725
DPM Course
Airtightness course
4 Repository roof
11870
1
DD205
1
DD204
1
DD213
1
DD050
1
DD150
1
DD051
1
DD215
14 - 20 temp
40-60 RH
18-25 temprepositories service atrium offices
Image Architype
Records Centre, offices,
conservation labs, teaching etc
1130m2
1321m2

5. Key design strategy:
Office isolated from repository
20—22°C
this side all
year
13-18°C
this side
is ideal
Image Nick Grant

6. <0.04 ach @ 100Pa with doors sealed
(Final test 0.4 ach included doors to office – air leakage route)
Airtight details developed with contractor
– their first Passivhaus
Image Nick Grant

7. Cost effective construction – concrete blocks and planks – no frame
Larsen trusses and blown cellulose.
Arts Council suggest £3,500/m2
HARC was £1,980/m2 (turnkey).
Image Nick Grant

8. Image Nick Grant

9. Records Centre - timber frame.
Same details as developed for the earlier schools.
(glass area is for architecture not Passivhaus)
Image Nick Grant

10. Image Nick Grant
Atrium exhibition area between
repositories and offices

11. Repository energy balance
• Simplest form
• Low IHGs 0.6W/m2
• c.a. 1 air change/day supply air vent
• No HRV
• Temp 13-20°C
• No cooling(except photo store)
• Inspired by Tim Padfield & Danish
archives
www.conservationphysics.org
PHPP 7

12. Moisture balance - monthly model
Annual average humidity is about
right +/- depending on English
weather.
Options:
1. Close control air conditioning
2. Passive buffering
3. Control vent on phychrometrics
4. Trim supply air humidity in
summer (100m3/h, < 10-15 litres
H2O/day

13. Buffering (roughly)
13
Max vent air H20 imbalance:
≈ +/-10 kg/day
EMC @ 40% RH ≈ 6.5%
EMC @ 60% RH ≈ 8%
= 13 %RH/% EMC change
c.a. 150,000* kg of paper etc.
10kg H20 x 30 days = 0.2% change in EMC
= 2.6% change in RH
(* Half of archivist’s estimate and ignoring building fabric
moisture capacity)
EMC of a paper sample from repository
measured at 6.9% @ 45% RH

14. How long to dry 1,800 t of concrete??
September 2014
Image Nick Grant
Alan Clarke
working the
antique
chemistry
balance
Home brew test kit
March 2016

15. They said it wouldn't work:
Sceptical client in design meeting:
“The Titanic was said to be unsinkable”
Alan Clarke’s reply:
“We are designing the iceberg”
Compromise: an iceberg with a BMS controlled heating system . . .

16. Titanic Versus Iceberg
Image Nick Grant
4 sensors/store, alarms,
duplex boilers, duplex
pumps etc. . .
An airtight concrete box
wrapped in old newspaper. . .

17. L
April May June

18. Troubleshooting 1
Unwanted hot water
running through repository
pipework.
Losses from insulated pipe
was enough to heat the
building!
- Fix - valves shut manually
(Large fan coils to meet 1kW peak
heat load/floor!)

19. Troubleshooting 2
Photostore dehumidifier installed
backwards so running inefficiently
and generating unwanted heat in the
service core. Fixed in June 2015

20. Troubleshooting 3
Faulty sensor wiring made the
heating come on when already
above set-point.
A year to fix but heating isolated
so not a problem for now.
How fast/automatic does heating
response need to be?

21. J
L
Valves to repository shut, fans turned off
Smart building Stupid building

22. February 2016 (no heating since June)
Did we really need an emergency standby boiler??
Very slight fluctuations in RH
with outside conditions.

23. March 2016, vent reduction experiment
Vent rate reduced from 250 to 100m3/h for whole repository building and
dehumidification switched off on 4/3/16 as an experiment.
RH crept up +2% but even more stable. In equilibrium with walls? Time will
tell!

24. Punch thanks to Lloyd Alter

25. Very even conditions
Original M&E consultants argued for circulating fans,
standard practice to avoid “cold spots“ .
Would have required cooling for the fan gains.
Ground floor 17.00°C 50% RH
First floor 17.86°C 46% RH
Top floor 17.87°C 49% RH
25

26. Supply air Dehumidification
(if needed)
• Ventilation is the main source of H2O
• So make building as tight as possible
• Supply c.a. 1 air-change per day
• Trim supply air when outside air humidity is ‘high’
• Don’t try and control on room RH.

27. What we imagined
DX coil for seasonal
dehumidification – on/off
control
Small fan 100 – 150m3/h
1.2 air changes/day
(c.a. 30W)
Filter
Uninsulated duct
Uninsulated duct

28. What we got
Now we know it works we can just use the cooling coil.
(but because it uses chilled water we need to protect from frost somehow)

29. Energy use – inc’ labs & offices
June 2014 – March 2016 - whole building
Gas 11kWh/(m2.a) c.a. £1,000/a
Electricity 34kWh/(m2.a) c.a. £11,000/a
PE ≈ 100 kWh/(m2.a)
Hopefully electricity use will decrease as building dries out and
lighting and other controls are sorted??
TFA:
Records Centre 1321m2
Repository 1130m2
Total 2451m2

30. Lessons
Reducing ventilation, heat, cooling and dehumidification load to
a very low level allows radically simplified control strategies – a
gentle nudge.
Supply air dehumidification @ about 2 air changes/day
successfully stabilised RH before the building was fully dry.
Simple is really hard to get built!

31. PD 5454 range
Open Energy Monitor remote access by Alan Clarke
Temperature °C
Outside air

32. supply air settings changed 17/6/16
> a month later
Offered to change settings
PD 5454 range
Open Energy Monitor remote access by Alan Clarke

33. Next time
• No BMS – save money and improve reliability
• Simpler dehumidification of air supply
• No frost coil (uninsulated ducts, turn fan off in extreme)
• Apply lessons learnt to the cooled photo-store
• Simpler heating – electric panel heaters?

34. Image Nick Grant
Questions?