1. Lucht circulatie in Data Centres een Low Speed Ventilation benadering Michiel de Jong, Low Speed Ventilation GreenIT EIA, Amsterdam, 2015

2. Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com 1. To cool the servers, air is needed, for 1[MW] IT ≡ 70[m 3 /s] (or 2,6M[ton/year]) 2. In conventional Data Centres, coolers are small. (money is earned with servers, not with coolers,.. therefore: maximum space for servers & minimal space for cooling solutions) 3. However,.. small volumes for cooling & huge amounts of air => high air speed => local pressure variations ( Venturi-effect ) => ‘Hot spots’ ≡ systemic problem

3. Hot spots: 1) fans working against pressure 2) hot air flowing back to front 4. Problem conventionally addressed by applying over pressure => 1) resistance ( See pressure profile ) => fan power & energy => a) energy costs => b) maintenance => maintenance costs => downtime risk => c) higher investment => 2) leakage => a) more air needed => higher speeds, etc Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

4. 5. Getting rid of high air speed 1.) <= large cross section area for cooling => a) low speed => no local pressure variations => no Hot spots Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

5. 3.) <= air availability : flow measurements instead of pressure control => simple and predictive measurements => feedback for stable control => control resilient to interruptions 2.) low resistance in the air trajectory => low fan power => a) low energy consumption => b) low maintenance Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

6. 6. CAPEX & OPEX => OPEX => less energy, less maintenance, less disturbances => lower operational costs (PUE :1.18 => 1.11/1.07) => CAPEX => less electrical infrastructure, less dry coolers, less control devices, less leakage prevention, smaller fans, etc. (5% E & MC) 7. Proven concept => 4 Data Centres currently working Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

7. 8. SUMMARY What LSV delivers; 0Hardware comfortup ( no hotspots ) 0IT life time up ( avoid high temps ) 0TIER Reliabilityup ( industrial components/ resilient climate control ) 0Air reliabilityup ( climate control based on air availability ) 0Investment levelsdown ( savings on E- and C-infrastructure ) 0 Maintenancedown ( lower fan speeds / less complex AC ) 0Energy consumptiondown ( lower fan power ) 0Comfort personnelup ( door to hot containment can be left open during maintenance without interrupting cooling ) Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

8. Fragen? Question? Dank voor uw aandacht Low Speed Ventilation – The Netherlands m.dejong@lowspeedventilation.com

9. Alfa Laval – Sweden, Low Speed Ventilation – The Netherlands mats.carselid@alfalaval.commats.carselid@alfalaval.com m.dejong@lowspeedventilation.comm.dejong@lowspeedventilation.com with P DC is IT power in [W], C pa is heat capacity of air in [J/kg K], ρ a is density of air in [kg/m 3 ] and ΔT is temperature difference between hot & cold air in [K] with ΔP a is the pressure drop of the air in [Pa], ρ a is the density of air in [kg/m 3 ] and v a the air speed in [m/s]. General layout DC with LSV: APPENDIX Raised floor/no outside air, Non-raised floor/no outside air, Raised floor/outside air, Non-raised floor / outside air