UNIT 44 REVIEW QUESTIONS ANSWER KEY GO BACK TO INDEX
44-1) What is the difference between infiltration and exfiltration?
44-2) What is the difference between exhaust air and ventilation air?
44-3) What benefit is there to supplying fresh air through ventilation versus simply
allowing fresh air to come in through infiltration?
434-4) What is makeup air?
44-5) How does a building end up with a positive or negative e pressure?
44-6) Explain how a balanced ventilation system works.
44-7) Explain how a heat recovery ventilation system works.
44-8) What is the difference between a heat recovery ventilation system and an
energy recovery ventilation system?
44-9) How can a building’s infiltration rate be accurately measured?
44-10) How can building pressure be accurately measured?
44-11) Why does the humidity in the air affect comfort?
44-12) How does the humidity in the air affect the load on an air conditioning unit?
44-13) Explain how a reheat system operates.
The air is cooled to the dewpoint in order to dehumidify it, and then
44-14) Explain how a heat pipe works.
A heat pipe is essentially a closed tube installed on a slant with refrigerant
44-15) How can heat pipes be used to improve the dehumidification abilities of air
conditioning systems?
44-16) Describe how a basic compression cycle dehumidifier works.
A compression cycle dehumidifier is an air conditioner with a single
44-17) Describe the energy efficiency ratings used for dehumidifiers.
44-18) Describe the system for rating dehumidifier capacity.
DH-1-2003 standard conditions: 60%RH, 80°F.
44-19) What effect do ambient temperature and relative humidity have on
dehumidifier capacity?
44-20) How do console dehumidifiers keep from being blocked with frost when
operating at temperatures below 65°F?
44-21) Which type of dehumidifiers are generally more efficient – small console
units or larger whole house units?
44-22) What advantages do whole house dehumidifiers have over small console
units?
44-23) Explain how a desiccant wheel dehumidifier works.
Desiccant wheel dehumidifiers use desiccants imbedded in a rotating
44-24) What types of dehumidifiers are used on large commercial applications?
44-25) What advantage do desiccant dehumidifiers have over refrigerated
dehumidifiers?
44-26) What is the CFM requirement for a ventilation system to provide 1.5 air
changes per hour in an 1800 square foot house with a 10 foot ceiling?
44-27) What is an air change?
44-28) Why do commercial buildings require more air changes per hour than a
residential house?