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Thread: How Rheem gets energy eff.
03-05-2005, 09:25 AM #1
Had service call to high eff. rheem unit - not sure how high the eff. is, but found bad condenser fan motor.
Original motor was 1/16th H.P.( .45amps ), can you believe it. Two blade fan. Local Rhem supplier did not even have this motor, had to go back with 1/5 HP.
This is one way to get eff rating. Undersize outdoor unit fan motor. Unit less than 6 yrs old
This is one of the reasons I don't trust high eff. equipment. What are the manufacturers going to do to get 13+ seer ratings next year.
Also have seen units whose reversing valve would energize & deenergize by the thermostat ( not the heat-off-cool switch ). Found out that that was to get higher eff. rating. Less energy usage if reversing valve was not kept energized in cooling cycle.
What other ways do manufacturers have to 'cheat' on eff. rating ??
03-05-2005, 09:33 AM #2
How do you know 1/6 hp was undersized? Pretty rare to see a 1/3 hp fan motor any more. Some brands go 1/8 - 1/10 hp these days. Use an Emerson Rescue motor and you can adjust hp from 1/3 to 1/6. Mounts fit Rheem outdoor units too.
03-05-2005, 09:37 AM #3
There is equipment out there that has spinning low pitch 16" 4 blade fans at 825 RPM with a 1/6 hp motor for 15+ years without problems.
If the condensor coils are kept clean, and the unit is located so water running off the roof doesn't go in the top of the unit, those motors last as long as any others.
The problem with Rheem/Ruud outdoor units is that they seem to act as yard hoovers more than most other brands. It is very rare that I see one on a service call that doesn't have a filthy condensor coil. Restricting the airflow through the condensor coil is a good way to kill a condensor fan motor.If more government is the answer, then it's a really stupid question.
03-05-2005, 10:33 AM #4
Seems to me the motors are selected based on airflow requirements through the outdoor coil and no reason to overpower them. Next time you look through your spec books at the efficient systems, look at the latent/sensible ratios of that rheem you didnt like compaired to others, look at the HSPF's of the heat pumps compaired to others. While your at it, notice it doesnt require a time delay or, liquid line solenoid valve in order to achieve SEER ratings.
Its too bad your distributor didnt have the motor in stock but he probably didnt want to sit on it for 4 years waiting to sell it when he can stock a trip-saver motor that can get you back on line.
Cleaning coils is part of owning an air conditioner. Its a fact of life. I'd far rather work on a unit with all the componants right there in front of me than one where I have to keep blocking the service panel after attaching my instruments anyday. If yeard debris is an issue, dont be affraid to stick some pump-ups under the unit to get it up off the pad a little.
03-05-2005, 11:08 AM #5
Its not 1/6 u guys
It is 1/16th hp
03-05-2005, 11:37 AM #6
Looks like we all need glasses. Never seen anything that small. Remember the model #?
Rheems do get dirty easy BUT with large footprint and wide fin spacing, much of that is surface dirt. The ones that really have a problem are the little cubes that are so popular. To get the small footprint, they use very tight fin spacing which lets the dust pack in between the fins. The rain washes the surface so homeowners & techs think the coil is clean when it is really packed.
I don't know that "cheating" is the right term for these techniques. With rising energy costs plus the new 13 SEER requirements, manufacturers have to use every method they can to drop the juice usage while keeping reasonable peformance. Also cheap homeowners are demanding cheap units so they also have to use the most cost effective methods they can do get this high SEER. If customers didn't mind spending a little extra on their HVAC, we'd really have some nice products instead of cheaper built, less reliable stuff.
03-05-2005, 11:51 AM #7
Yeah, what model was it, the lowest I see is .9 fla at 230v. Some 460v might have a fla of .6 but I dont see any with a .45 fla... Sure it was original motor?
03-05-2005, 12:25 PM #8
The model # rpfb-024jas
The motor wiring seemed to be original, as was the rust around blade hub. unit less than 6 years old
03-05-2005, 01:12 PM #9
That's an old 9 SEER so would date before 1992. According to the parts list on Rheemote, the factory motor was a 1/5 hp, 1075 RPM single speed.
03-05-2005, 07:38 PM #10Regular Guest
- Join Date
- Nov 2001
he said 4 years
03-05-2005, 09:11 PM #11
That is not a 6 year-old furnace. The S in the JAS tells you it is a tin can comp. Rheem hasn't used a tin can for 10 years or so.Karst means cave. So, I search for caves.
03-05-2005, 11:36 PM #12
I remember these motors well. They were OEM installs that were never used for replacement parts.
If memory serves me, they were also mounted by three screws that went through the motor and the replacement motor has 4 screws that tap into the side of the motor.
Many types of games are played to create slight efficiency changes. The lack of a crankcase heater can get some units over the fractional hump they need to reach the next SEER level. Variable speed blowers are a very good efficiency booster. Even though a 90 second time delay for indoor blowers is bad for humidity control, it adds .2 SEER to the rating.Government is a disease......masquerading as its own cureEcclesiastes 10:2 NIV
03-05-2005, 11:51 PM #13Originally posted by karsthuntr
That is not a 6 year-old furnace. The S in the JAS tells you it is a tin can comp. Rheem hasn't used a tin can for 10 years or so.
They still use tin cans in their low-end units.
The scroll in the 10 seer is an option.