1.Based on acture usage, periodically remove the primary filter cleaning ,the cleaning cycle is generally 3-6 monhths. 2.When the early effect of the normal exchange or clean the filter air filter, still can not achieve the desired cross-section wind speed then adjust the fan voltage, and thus achieve the desire uniform wind speed. 3.Generally when the fan operating voltage adjustment to the highest point in the use of eighteen, still can not achieve the desired wind speed ,description of the filter on the high efficiency filter dust too much (filter kong has basically stuck to timely update) general efficiency air filter use a period of eighteen months. 4.Replacement of high efficiency air filters, should pay attention to the correctness of the model dimensions arrow wind devices, and pay attention to the peripheral sealing of the filter is absolutely no leakage occurs. 5. SATISFACTION GUARANTEE: We are pretty sure that you will love your new Laminar Flow and you will feel the difference right away, but if for any reason you feel the Laminar Flow is not working for you, contact us, and we will offer you a full refund of the original purchase price for up to 36 months.