seer rating doesn't match power draw

Page 2 of 2  


It's Btu/h, ie Btus per hour. BTUH would be Btus times time...
Should we discard our ACs when they run out of Btus? :-)
Nick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On 31 Jul 2005 04:01:14 -0400, snipped-for-privacy@ece.villanova.edu wrote:

Yes.
Well... a BTU is a BTU per hour for an hour, making it a BTU per hour hour. So, what you are saying is a BTUH is a btu per hour hour hour. Since "per hour" and "times hour" cancel out, a BTU per hour hour hour equals a BTU per hour. Therefore, BTU/hr == BTUH. :-)
-----BEGIN PGP SIGNATURE----- Version: PGP 7.1
iQA/AwUBQuyOMgIk7T39FC4ZEQIQOgCffIk8oq+nliPnYp8++SI0jQbfL9kAn31u E3PKGD9uhSjKeUkXWCNtoHQi =odfM -----END PGP SIGNATURE-----
--
-john
wide-open at throttle dot info
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@ece.villanova.edu wrote:

In a mathematical formula yes, but as an abbreviation of language BTUH is read btu per hour :) It's yet another case of dumb-ass convention ;)
hvacrmedic

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Carolina Breeze HVAC wrote on 7/30/2005 7:24 AM:

Exactly.
Elaborating on this answer, for lights, power is watts times amps. This is still true *instantaneously* for everything, but for motors the current and voltage or not in phase. These means that part of each cycle voltage and current are of the same sign, resulting in positive power consumption, just like lights.
But for the rest of the cycle,they are of opposite sign, so that the power is negative. In other words, the motor is actually returning power to the power company for this portion of the cycle.
You only care about the average power consumed over an entire cycle, which for a motor running at full speed is considerably less than the rms current times rms voltage.
--
Rick Matthews snipped-for-privacy@wfu.edu
Department of Physics http://www.wfu.edu/~matthews
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


That's correct: The SEER is calculated to include the phase shifts etc. introduced by the loads, which is why direct calculations such as the OP used won't wash. In addition, nameplates & labelling isn't always accurate. It's often stated to be even higher than the actual draw, just to account for the possible variations in the production of multiple units. So they use a max number on the plates and for the saftey agencies. Plate numbers are only for sizing wiring to the unit. If it has a SEER rating, and a safety label (UL, CSA, CE, et al), which is a requirement, then the numbers are correct.
HTH
Pop
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1) volts X amps is not watts in AC. It is volt-amps (VA). Actual watts will be less. 2) 7 amps on a 240 volt blower motor? It is probably a 120 volt motor. 3) As the other guy said, amps on the name plate is usually maximum load.
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.