they don't use heat exchanger in the winter?
You'd think so, but they still use AC. They do have "economizers" which are basically dampers to use outdoor air but think the compressor still runs.
If it was me we'd just use a combination of heat exchangers and HRVs to control heat and humidity. Would only really need AC for like 2 months of the year. If you keep the equipment rooms at or below 25c it's optimal and it's pretty rare for it to be hotter than that outside even in summer.