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HRV marketing director Justin Boyes confirmed changes were afoot.
He said that there had not been the anticipated demand for HRV's window film or double-glazing insulation products, which were now being discontinued.
''There are about 30 people affected ... It's hard to know how many will be let go.
''We're looking to redeploy some,'' Mr Boyes said.
There was growth in other product markets, such as solar energy installations, he said.
Talks were under way with affected staff.