Precision cooling (CRAC and CRAH) maintenance in Toronto
A UPS room that runs hot uses up its batteries years early. Precision cooling maintenance keeps the CRAC and CRAH units that serve UPS and IT rooms at their setpoints: filters, coils, fans, the refrigerant or chilled-water side, humidity control and the sensors that tell the units what the room is doing.
Key facts
Why Does a Hot UPS Room Shorten Battery Life?
Because battery aging is chemistry: APC's rule is that every 8 degrees of extra heat cuts sealed lead-acid battery life in half, and Vertiv's numbers show a room averaging 35 degrees instead of 25 does exactly that. Batteries want 20 to 25 degrees for maximum service life (Eaton); servers tolerate more, with ASHRAE recommending an 18 to 27 degree inlet. Cooling maintenance holds the room to the numbers, and the UPS visit reads the battery temperatures against the new setpoints.
In this video
- 0:00 Why does a hot UPS room shorten battery life?
- 0:16 What does heat cost?
- 0:39 What should the room hold?
- 1:07 What does cooling maintenance cover?
- 1:31 Talk to Symetrix Canada
Transcript
Why does a hot UPS room shorten battery life? Because battery aging is chemistry, and chemistry runs faster in the heat. APC puts a number on it: every 8 degrees of extra heat cuts the life of a sealed lead-acid battery in half. The fix is holding the room to the numbers.
What does heat cost? APC expects 3 to 5 years from most of its sealed lead-acid batteries in a normal room. Vertiv's number: a room that averages 35 degrees instead of 25 cuts battery life in half. Heat works on the UPS itself too. Eaton schedules the primary capacitors for replacement around year 7, and a warm room pulls that forward.
What should the room hold? For the batteries, Eaton gives 20 to 25 degrees for maximum service life, and CSB allows 5 to 35 with the average below 25. The IT equipment in the same room tolerates more: the data-centre thermal guideline recommends an 18 to 27 degree inlet, and 15 to 32 is allowable for class A1. A room set for the servers can still run the batteries warm their whole life.
What does cooling maintenance cover? The filters and coils, the fans, the humidifier and the drains, and the sensors that tell the units what the room is doing, calibrated against a reference. Refrigerant work belongs to technicians holding an ODP card and a trade certificate, the pair Ontario requires. The readings, the setpoints found and left, and the parts to quote land in the report.
Book it with the UPS visit and one window covers both: the cooling units are serviced, then the battery temperatures are read against the new setpoints. Symetrix Canada services UPS systems across Toronto, the GTA and Ontario, with an around-the-clock emergency line. Reply and quote within 4 business hours. Call 1 (438) 800-0382. Find Symetrix Canada on the web.
The numbers the room is held to
| Space | Target | Source |
|---|---|---|
| IT equipment inlet, recommended | 18 to 27 °C [1] | ASHRAE, classes A1 to A4 |
| IT equipment inlet, allowable for class A1 | 15 to 32 °C [5] | ASHRAE |
| Humidity, recommended | Dew point from -9 °C to 15 °C, and 70% RH or 50% RH depending on the room’s contaminants [6] | ASHRAE |
| VRLA battery cabinet | 5 to 35 °C, with an average below 25 °C [7] | CSB |
| UPS internal batteries | 20 to 25 °C for maximum service life [2] | Eaton 91PS/93PS |
The IT room and the battery room want different things. Servers tolerate a warm inlet; lead-acid batteries do not. A UPS room cooled to the top of the IT range runs its batteries warm for their whole life.
What a visit covers
| Part | Checks |
|---|---|
| Filters | Replaced; pressure drop noted |
| Coils | Inspected and cleaned; fins straightened |
| Fans and belts | Bearings, belt tension, EC fan speed against demand |
| Refrigerant circuit (CRAC) | Pressures, superheat, subcooling, leak check, by certified technicians [4] |
| Chilled-water side (CRAH) | Valve stroke, entering and leaving water temperatures |
| Humidifier | Canister or electrodes, drain, output against setpoint |
| Condensate | Drain pans, pumps and the leak detection under the unit |
| Controls and sensors | Calibrated against a reference; alarms tested to your monitoring |
| Airflow | Blanking panels, perforated tile placement, containment doors |
The report gives the readings, the setpoints found and left, and the parts to quote.
Why it is booked with the UPS visit
Heat, poor utility power and frequent short discharges all shorten UPS battery life [8], and heat is the one the room controls. Fans and capacitors in the UPS also age faster in a warm room; Eaton schedules power-train capacitors around 7 years of operation [9]. One window covers both: the cooling units are serviced, then the UPS visit reads the battery temperatures against the new setpoints.
Common questions
What temperature should a UPS room be?
For the batteries, 20 to 25 °C, the range Eaton gives for maximum battery life [2]. IT equipment in the same space tolerates more: ASHRAE recommends an inlet of 18 to 27 °C [1].
What is the difference between a CRAC and a CRAH unit?
A CRAC (computer room air conditioner) has its own refrigeration compressor. A CRAH (computer room air handler) uses chilled water from a central plant and a fan, with no compressor of its own.
Who can work on refrigerant in Ontario?
A technician with an Ozone Depletion Prevention (ODP) certificate card. The card alone does not allow repairs to refrigeration equipment, which also need a trade certificate [4].
How often should CRAC units be serviced?
On the manufacturer's schedule, with filters checked more often in dusty rooms. Critical sites set a shorter interval in their maintenance contract.
Sources
- ASHRAE TC 9.9, 2021 Equipment Thermal Guidelines for Data Processing Environments, reference card, Table 2.1, recommended envelope
- Eaton, Eaton 91PS/93PS UPS 8-40 kW User's and Installation Guide, P-164000493 rev 006, p. 16
- Vertiv, Liebert APM2 UL Modular UPS User Manual SL-71948, printed p. 118 (PDF p. 126)
- Ontario Ministry of the Environment, Conservation and Parks, Certificate to handle refrigerants, page body
- ASHRAE TC 9.9, 2021 Equipment Thermal Guidelines for Data Processing Environments, reference card, Table 2.1, allowable A1
- ASHRAE TC 9.9, 2021 Equipment Thermal Guidelines for Data Processing Environments, reference card, Table 2.1, recommended
- CSB Energy Technology, VRLA Battery User Manual (Operation and Handling, Rev Dec 2024), operating temperature
- Schneider Electric, Smart-UPS On-Line SRT2200XLA/SRT3000XLA Operation Manual, p. 2
- Eaton, Straight talk about capacitors in your UPS (WP153009EN), capacitor service life section
Updated