| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a chemical substance anaphylaxis by simultaneously supply ing and exhausting the air when indoor side chemical substance concentration exceeds an allowable limit value, cleaning the outdoor air by a filter, heat exchanging it, supplying it to the indoor side, introducing the indoor side contam inated air to a return air route, removing it by the filter, and then returning it to the indoor side. SOLUTION: When chemical substance concentration of the indoor side R exceeds an allowable limit value, a sensor 12 senses it, and operates exhaust and supply fans 5, 6. The air of the indoor side R is introduced from a ventilating inlet 1a at the route 1 during operating, passed through a total heat exchanger 9, and exhausted from an exhaust outlet 1b to the outdoor side P. The air of the outdoor side P is introduced from an air supply inlet 2 at an air supply route 2, passed through the exchanger 9 and a first filter 8 for attracting pollen and dust and supplied from an air supply outlet 2b to the indoor side R. Contaminated air of the indoor side R is introduced at a return air route 3, cleaned by a second filter 10 for attracting chemical substance, combined within the route 2, and supplied to the indoor side R together with the supply air.</p> |
