Question

3. A portion of a museum is required to be conditioned to 75°F/50% RH year round. Since it's a museum, the humidity must be controlled. Under design conditions, this portion of the museum has sensible cooling loads of 35,000 Btu/hr and latent cooling loads of 15,000 Btu/hir The air handler (Figure 1) designed to maintain conditions has a cooling coil, a reheat coil, and a steam humidifier. (The steam will be at atmospheric pressure.) System control is achieved by modulating the chilled water flow, adjusting the fan speed, modulating the reheat coil, and modulating the steam humidifier. The chilled water coil, reheat coil and humidifier can all be modulated to zero - that is, for many hours of operation, only one or two of the three components will be operating. At cooling design conditions, the air exiting the cooling coil will be 52°F/90% RH. At cooling design conditions, the ODA is at 93°F/72℉ (WBT) and will Wi and 75% by mass RA. The heat given off by the fan may be assumed negligible

Please show work and explain how and why each step is used. Use psychrometric chart.

Answer 1

Gven cata 8 The museum hos sensiblo cooking leaols35,000 Bru Ihu auent Cooking loads 15,0c0 rulho ODA 293 F 729F (wBT) ODA and 5% by ross RA 2t di Picason 145F Des n condition

combing O & e eh h98.5335 + 8.95 h3 3 485 T3401 F Sensible Coolng load深 -35Co (8tulha) 15000 (Brulha So calculate ensib ear actoo a feasible kating to using RH 0 ora Lood s 28 ん_hg: 38-5-28

Sy me at 1 rn (10-5) 50000 M5006061 Vu 4a61(.) to3 Hese condirons As8uve fea a Comfen be on. ourler cordlirion u Hee (31-21-5) 5000d

5 x5000 (35-3) x 5000o 6.5 x 50000 (b) atap tbw are leaving e aoing coi V 623.6a1