Lennox AC Pros - help with system selection

[Stilwell]

I am putting a new HVAC system in my house. After getting bids from local companies I have settled on a Lennox system. However, I need some clarity on SEER and EER ratings. In general, I understand what these mean but I am confused due to the following:

The furnace is a SLP98UH070V36B variable speed.

With a 14 SEER AC unit the AHRI EER rating is 12.50 and the SEER rating is 15.20.
With a 16 SEER AC unit the AHRI EER rating is 11.20 and the SEER rating is 15.50.


Why does the 14 SEER have a better EER rating?
How can a 14 SEER AC unit have an AHRI SEER rating of 15.20?
Why is the 16 SEER SEER rating only .30 better than the 14 SEER SEER rating?

The 16 SEER unit is a two stage unit. Is a two stage unit better or worse than a single stage unit?

The unit sits next to my patio so noise level is a concern and the 16 SEER is advertised as a little less noisy, 70 db vs. 74 db. Based on what I know about the db scale, this is a decent difference and the price difference (about $450) is likely justified on this alone but I would like some feedback on efficiency ratings and the single vs. two stage feature.

Thank you.

 

[Stilwell]

Thanks for the feedback. The company I am leaning towards did do a size calculation and they are replacing all of the ducts, both return and supply. They are a large reputable company with good references so I can only assume they are planning the system correctly...not sure there is anything I can do to verify as this is way out of my field of expertise. This is not the same company that gave me the AHRI specs but, same equipment.

Thanks again.

 

[brewchief]

SEER rating will change depending on the indoor coil and metering device used. Depending on the indoor unit you could have a pretty good assortment of indoor coils to choose from, with proper selection you can gain a point in SEER rating pretty easy. If you want quiet consider going to the XC17, it's single stage but very quiet, I've had people walk up to me while I was charging one and ask me when I was going to turn it on before(this is while it is running). XC17 is also Icomfort enabled if you want to use the Icomfort stat. Whatever system you end up with I would recommend use of a good quality media filter, we either use the Lennox healthy climate or Aprilaire filters, both are good and should only require replacement once or twice a year.

 

[Stilwell]

Thanks brewchief. I will bring up the XC17 with them as well as other internal coils to see what changes that might make. This stuff is really hard to pin down.

 

[truckman5000]

lennox replacement parts are more than every other brand

 

[Jay41]

lennox replacement parts are more than every other brand

Not if you work for a Lennox dealer.

 

[Teken]

SEER rating will change depending on the indoor coil and metering device used. Depending on the indoor unit you could have a pretty good assortment of indoor coils to choose from, with proper selection you can gain a point in SEER rating pretty easy. If you want quiet consider going to the XC17, it's single stage but very quiet, I've had people walk up to me while I was charging one and ask me when I was going to turn it on before(this is while it is running). XC17 is also Icomfort enabled if you want to use the Icomfort stat. Whatever system you end up with I would recommend use of a good quality media filter, we either use the Lennox healthy climate or Aprilaire filters, both are good and should only require replacement once or twice a year.

Simply put, what part of the coil and metering device affects the SEER rating? The diameter, length, amount of flow from the metering device?

 

[brewchief]

Simply put, what part of the coil and metering device affects the SEER rating? The diameter, length, amount of flow from the metering device?

A TXV will improve the seer rating over a fixed orifice in almost all cases.
A larger coil will often improve the rating also, think 2 1/2 ton coil with a 2 ton condensing unit.

AHRI has a site that you can input your coil and condenser and see what seer rating it should have.

We make sure that our systems are matched to provide the rated seer and provide a AHRI number for the customer.