Change the coil but not the condensor/compressor
Change the coil but not the condensor/compressor
(OP)
I have a Carrier 38HD A030C nominal 30,000 Btuh compressor/cond unit and a Carrier CE3AXA0300000ABAA 30,000 Btuh coil. My heater and blower unit is rated at 1450CFM but my coil is only rated to 1000 CFM nominal, 1250CFM max. This will kill my extra 200CFM which I really need for my 3300 sq-ft house. I was wondering how I can tell if I could simply change out the coil for the 38HD A042C coil rated at 54,000 Btuh and 1450 CFM nominal. Since it is a bigger coil, will my compressor be able to keep up? I have all of the data, just having trouble figuring it out.
Thanks!!!
Thanks!!!





RE: Change the coil but not the condensor/compressor
2. Too large evaporator may increase superheat to a value that will dammage the compressor (too high discharge temp.)
3. With design conditions and the known capacity and air flow, you can use the psychrometric and the refrigerant LogP-I charts to find what will happen.
RE: Change the coil but not the condensor/compressor
Simliar to the previous post the question of capacity vs. load can't be addressed based on what you have provided.
RE: Change the coil but not the condensor/compressor
http://www.commercial.carrier.com/wcs/prod_physicaldata/0,1180,CLI1_DIV12_ETI440_PRD100,00.html
I have an 030 coil and want ot go to a 042 coil. The coils are as listed above with product data here:
http://www.xpedio.carrier.com/idc/groups/public/documents/techlit/ce3a-2pd.pdf
Hope this helps.
Thanks again...
RE: Change the coil but not the condensor/compressor
RE: Change the coil but not the condensor/compressor
RE: Change the coil but not the condensor/compressor
Thumb rule figures:
400 cfm/Tr: yours is 1450/2.5=580 (+45%)
350-700 sq ft/TR: yours 3300/2.5=1250 (>+78%).
030 evaporator at 67F WB RA and 40F evaporator with 1250 cfm yields 48,000 Btu/hr.
042 with 1,400 cfm yield 68,000 Btu/hr, which means 30% of heat transfer area will be used by the system for refrigerant vapor (additional) super heating.
This is just an indication: the actual working point will be balanced by actual performance curves of fan coil and condensing unit at prevailing ambient conditions.
I believe the required figures will be somewhere between your figures and the rules of thumb 3300/(<700) -> (>4.7)TR and (>4.7) x400 = >1880 cfm
RE: Change the coil but not the condensor/compressor
Can I get a consensus from the panel?
Based on the info going from 030 to 042 in the coil will work fine with my 030 compressor?