```ts
export function meanWindow(readings: number[], size: number): number[] {
  if (size === 0) return [];

  const results = [];
  for (let i = 0; i <= readings.length - size; i++) {
    const window = readings.slice(i, i + size);
    const sum = window.reduce((a, b) => a + b, 0);
    const mean = Math.floor(sum / size);
    results.push(mean);
  }

  return results;
}
```