The reactant gas manifolds (12 15) of a PEM fuel cell are modified to
provide insulated manifolds (14a) having inner and outer walls (30, 31)
closed off by a peripheral wall (35) to provide a chamber (36) which may
be filled with a vacuum, a low thermal conductivity gas, a VIP (59) or a
GFP (63). Single walled manifolds (14d, 14e) may have VIPs or GFPs inside
or outside thereof. An insulation panel (40) similarly has inner and
outer walls (42, 43) closed with a peripheral wall (45) so as to form a
chamber (46) that may contain a vacuum, a low thermal conductivity gas, a
VIP or a GFP. The tie rods 9a may be recessed 50 into the pressure plate
11a of the fuel cell stack to allow a flush surface for the insulation
panel 40.