The paper discusses a radon reduction demonstration project in 1986 on 10 houses in Clinton, NJ. As part of this effort, radon was measured before and after radon reduction techniques were applied. The purpose of the measurements was to ascertain the effectiveness of the radon control methods being used. Since radon concentrations are normally highest in a depressurized house (commonly observed during cold winter months), efforts were made to emulate winter depressurization. Before radon reduction techniques were applied, four houses were tested using a common window fan to induce 7 Pa of negative pressure. Results of these tests showed that fan-induced negative pressure has a dramatic impact on radon concentrations. For some houses, this technique was shown to adequately emulate winter-time radon entry rates during warm summer months. Potential problems which may cause this technique to fail in some houses were identified.