Sigarms
Super Member
Richard,
SEER is the "Seasonal Energy Efficiency Rating" all that means is the higher the seer the less energy that system will need to cool the same space.
When you get into the higher seer units you get into the variable speed blowers in the furnace, variable compressors in the condenser or multi stage compressors.
He's right about control boards to run all that stuff, it's crazy expensive, just a defrost board is $190 and it's the size of a dollar bill folded in half usually. The more advanced the system the more advanced controls it takes to manage the equipment.
But in a perfect world you won't ever lose a control board. Moisture, heat, vibration, bugs ext all can lower the life of a exterior board, they do fail prematurely sometimes.
It also takes a bit of a smarter installer to install and set up correctly a high seer unit with variable speed everything.
I'm a fan of a oversized indoor coil paired with a correct size condenser to your house, you can take a 15 seer unit, put a variable speed blower in the furnace and oversize the indoor coil and make it a 16 seer without the cost of a 16 seer system.
Generally the higher the seer the more surface area of the indoor coil as well as a much larger outside coil, if you see the outside condenser stand 5ft tall and 3.5ft wide on a less than 2000 sq ft house that's why, the coils are massive.
Another bit of info for you, I have installed Gibson, Carrier, York, Lenox, Trane, Rheem and a few others I can't remember and most use either a Copeland or Emerson compressors. Scrolls will be in every heat pump, they handle liquid slugging much better than hermetic compressors found in regular A/Cs, im not sure what Trane uses, they wrap there compressors and there usually like 3 times bigger than the normal Copeland's and Emerson's. I'm not a fan of Trane, idk why there compressors are so freaking massive and heavy but they are.
1 - There are WAY to many variables with a retrofit replacement to make a blanket statement that the higher the SEER, the less energy that system will need (see my previous post about existing ductwork for one, and static pressure issues affect on a varaiable speed blower just for 2 quick points).
2 - EER, HSPF and COP is just as, if not more important that SEER rating.
3 - If the outdoor unit is AHRI rated with the indoor coil, the coil will NOT be oversized. What you're doing is making the same mistake as many others as assuming that the model number on the coil is the actual tonnage of coil (although there is some relationship between the coil model and outdoor model).
4 - A X-13 motor (which is a ECM motor) is MORE energy efficient that a true "variable speed" ECM motor. It is wrong to make a blanket statement that by adding a variable speed motor to a system you automatically increase the systems SEER rating (I can think of multiple brands / AHRI match ups where this is the case).
5- Scrolls will NOT be in every heat pump. When the scroll first came out, people thought it was the godsend to end compressor failures. Not the case. I've seen studies from manufacturers that point that the failure rate of a rotary compressor has a lower failure rate (somthing to be said for a simple piston design).
I'm not trying to be argumentative, only pointing out that you're making blanket statements which are incorrect and can be misleading.