Very High Efficiency Air Conditioners

[Mike Henderson]

Companies are making very high efficiency air conditioners, with a SEER of 23 to 24.5. Does anyone have any experience with one of these very high efficiency air conditioners?

How much extra was it to buy compared to a regular unit (SEER of about 13)?

Was anything special required for the installation?

Did you notice a real difference in your electric bill?

Any other comments?

Mike

[David Weaver]

Which brands are you looking at? The stuff like the mitsubishis?

[Mike Henderson]

Which brands are you looking at? The stuff like the mitsubishis?
I'm not looking at any particular brand (yet). I'm interested in a split system, about 5 ton (60,000 BTU).

I'm interested in anyone's experience with a very high efficiency A/C - any BTU level.

Mike

[Dan Hintz]

I don't remember the exact SEER number, but it was over 20... installed two(?) years ago to replace a leaking system that had a combined SEER of <10. Night and day difference, not only in keeping the house at proper temp, but utility bill-wise, too.

[David Weaver]

I have a combination A/C and heat pump being installed in an add-on room that wasn't practical to tie in to ducting. But it's not in the stratosphere, it's one of the 21 seer mitsubishis. But I chose it for a different reason, it appeared that the high efficiency units have better heat pump capacity at lower temperatures.

Presume that pacific gas brings your heat, so you're looking at A/C only?

Mitsubishi had a couple of really high seer (26,27) units, but I didn't see them when I was sizing stuff, and I probably didn't see them because the contractor brought back stuff in the range that I asked for (20+).

I'll bet my whole house A/C is probably 6 or 8 seer, but it's not hot enough around here to justify replacing it ($ wise) until the furnace needs to be replaced (which itself is cheaper to keep right now because it's reliable and gas is dirt cheap here).

[Lee Schierer]

I have a Climatemaster Geothermal heat pump with a 22.0 EER/4.1 COP that we have operated for five years with absolutely no problems. The HVAC contractor installed it and it required no special installation. Since our new unit added A/C we noted that our electric bill for the first summer was exactly the same KW that we had used the previous summer running fans and a dehumidifier except that our house was a constant 74 degrees that summer with the A/C whereas the previous summer it was much warmer. I can't speak to price compared to a unit with a seer of 13 as geothermal units didn't go that low.

[David Weaver]

22 EER is on another planet compared to air to air exchangers. The looking I've done lately has mid 20s seers corresponding with EER ratings of 14-15.

Not that it's a suprise that you can get a lot more btus for a watt of electricity from a geothermal system, and the bonus being that it doesn't struggle in temperature extremes.

[Mike Henderson]

Presume that pacific gas brings your heat, so you're looking at A/C only?

I use gas for heating but the unit I have now combines both A/C and heat. The A/C is electric and the heat is generated by gas, with electric fans to distribute the air. But, as you mention, I'm really interested in the efficiency of the A/C.

Mike

[Steve Peterson]

Our house came with an SEER of 20. It looks like a traditional outdoor box with swamp cooler type pads around the outside of the heat exchanger. My thinking is that the evaporative cooling helps remove the heat better. It would seem like it should only add an extra $1000 or so to the cost of the unit. Maybe there is more magic involved, because an SEER of 20 should cost 33% less to operate than the standard SEER of 13. The payback time would be less than 1 year at the rate that my wife runs the AC.

Steve

[Andrew DiLorenzo]

My Ac is an 18 SEER which means the air handler is a little larger than minimum and the outside coils are huge, to dissipate the heat. The blower fan is two speed so at low speed the unit dehumidifies more. The salesman told me that after a SEER of 18 there are special tricks to make the units more efficient, but none that are particularly cost effective. Make sure the special tricks work for your climate and then do a cost payback on the extra efficiency. The extra money MAY better be spent on insulation or preventing air infiltration for instance. For me, the most cost effective was at 14 SEER. I ignored my own advice to opt for the new higher level of efficiency, and yes I took steps toward more insulation and increased air-tightness in the form of new doors and windows. The cost comparison was not that far odd. By the way, the double pane insulated windows will never pay for themselves in terms of energy efficiency in my house. However, they block a lot of noise and that is worth a lot! If I had to replace the doors again, I would opt for doors with magnetic weather seals as opposed to compression foam.

[Steve Rozmiarek]

I just had a new super high efficiency system installed in my new office. Haven't used the much AC yet, but one obvious thing, the installation is enough different that just upgrading all the duct and returns makes an enormous difference. Apples to apples comparison for my system to the old one will end up being impossible subjectively though, it feels better, you really don't even know its running. I don't remember the specs, can get them Monday if you really want to know.

[Brad Adams]

You won't be able to get 23 seer in a five ton a/c. You will have to go to geothermal to get that high with one unit.

[Mike Henderson]

You won't be able to get 23 seer in a five ton a/c. You will have to go to geothermal to get that high with one unit.
I saw that when I did the research - big units have lower SEER. But you bring up a good point - I'll look into splitting the system into two units. That may give me more flexibility to only cool the parts of the house I want to cool, and thus save money by using less A/C and in getting a higher SEER unit(s). But the up front cost may make that unfeasible.

Mike

[Larry Frank]

I am also looking at replacing my gas furnace and A/C. I have looked at a Trane with a Seer of up to 20. I think that Carrier has a unit with similar SEER.

[Tom Fischer]

We have two Goodman heat pumps 2 ton each, 2006. I think they are SEER 14.
I never use them for heat, only AC. Think that helps the longevity.
Also I changed all the windows 2 years ago, put in all new Pella.
The glass has a very slight green tint in the summer.
I think they help a lot keeping the house cool.
House is 2500 sf, ranch. Cost of 1 month AC in average July is $100.