AboutFred Weldin Expertise I can't help you if your whatsis won't work, people (Especially if it's a refrigerator); I have no experience with appliances, and I haven't been involved with H&AC service and repair since March 08, 1996 (Thank the Lord); I reject appliance questions and H&AC "Service and Repair" questions (31 to date in December), so if you want to know why your whatsis isn't working like it used to, ask someone else. I delete answers that are unread after one week (about three a month).
If you have questions about how big a unit you need, if one room's warmer than the others, if you want an opinion on bids received, etc. just ask. Do visit askweldin.com, there's a lot of good information on sizing, ductwork, efficiency, as well as some techniques accomplished DIY-ers can use to troubleshoot and improve their H&AC.
Finally, I want to thank all of the kind, serious people whom I meet here; I enjoy working with you.
Experience 50+ years in the business. See askweldin.com
Education/Credentials B of ME U of D 1965, numerous classes and seminars since.
Question We have a 1400 sq. ft. condo with about 30% of the walls facing west, getting a lot of sun in the afternoon/evening. We have to replace our water-sourced heat pump HVAC unit. The old unit was from 1980 (original) and did a decent job, although it would continuously run in the summer when the temp got above about 88 deg here in DC. The compressor on it finally died this year, with other damage in the wiring making it unsalvageable.
My dilemma is this: go with a 19,900 BTU or 24,800 BTU replacement? The 19900 BTU unit is what we are replacing. I like to think the upgraded cooling BTUs at 24,800 would make this place cooler, but then I also saw that the CFM increases from 585 to 800 on the new unit. I don't know if that would work with our existing ducting. I'm concerned about the noise this might generate and the extra cost of a bigger unit.
You didn't say it was uncomfortable when the unit "would continuously run", and the unit lasted 29 (WOW!!!) years; on the face of it, the unit is correctly sized. Your ductwork is sized for 585 CFM, if you're lucky; there's no way you'll deliver 800 CFM, and you may experience compressor problems (IE: Shutdowns and/or premature failure) due to insufficient airflow through the larger unit. Go with the smaller unit.
You might want to have someone check incoming fluid temperature and flow in hot weather, to determine whether temperature and GPM meets spec; it might be the central system is short changing you.
