New House System

[nathan9999]

First of all I want to thank the professional members who take their time to educate each other and homeowners like me about the important issues of selecting the right contractor and relative benefits of different equipment options.

I'm building a new 3139 sq ft house in Bakersfield, CA (hot dry summers and mild winters). Based on much of the feedback on the this site I have decided to go with a lower efficiency split system (probably not over a 13 SEER with a TXV, and 80% heating rating).

But I have been convinced that there is some benefit of a two speed or variable speed system in terms of increased comfort.

I see that some manufacturers do not offer 2 speed or variable speed in their lower efficiency units.

Could you list some of the manufacturers that do offer 2 speed or variable speed units in a 12 or 13 SEER and 80 AFUE?

Thanks very much.

[Gunnery Sergeant Hartman]

none that I know of...

[carrier4u]

CARRIER

[docholiday]

Rheem and Ruud offer an 80% 2 stage variable speed unit. the RGPL series.

[nathan9999]

I just found a York Deluxe Diamond 80 2 stage furnace and a York Olympian TS Series 2 speed AC unit which runs between 12 and 13.5 SEER. Any experience with these units?
Thanks

[docholiday]

The deluxe diamond is not a variable speed unit. The ultra is and its a medocre unit by comparison.

[nathan9999]

Doc,

The York web info shows the Deluxe Diamond to be a 2 stage and the Ultra to be a variable. Would a 2 stage provide the comfort benefits (increased filtering, etc.) that I have read about on this site? Or do you have to go with a variable?

[docholiday]

2 stages of heat simply gives you longer run times at a lower btu output for more even temperature control. Granted because it does run longer it will filter more effectively. The ultra is both 2 stage and variable speed. There is only one furnace on the market that is variable for both heat value and blower and it is not an 80% furnace.
That would be the mod90 but that wouldnt be comparing apples to apples.

The VS motor allows you to control humidity to some degree in summer a little better and generally it costs less to operate the fan motor alowwing you to run a continuous fan at a lower speed that constantly filters. The VS will also offer a constant airflow when other things change such as filter accumulation or system balancing to protect the equipment. Obviously high humidity control is not a requirement.

Since you live in a dry climate you need to determine the features you want. For that reason, a two stage a/c system is almost a moot point for you. Since dehumidification is not a requirement for you, I am afraid 2 stage cooling would be an expense you dont really need but agian you can get longer run times for even cooling. Generally sensible temperature swings from cycling in cooling are far less noticable then they are in heating.

If I were estimating a job for you as a consumer, based on what you appear to want I would recommend a 2 stage, variable speed heating system with a single speed 13 SEER a/c system unless local utility rebates offered enough to upgrade.

[Edited by docholiday on 02-10-2005 at 01:44 PM]

[aircooled53]

American Standard
Don't know what btu rating that you would need.


AUDO__R9V5K-(2)stage gas /variable drive Furnace
TXCO__S3HPC-Evaporator/TXV
7A20__A1000A-12.0 S.E.E.R.

If you do a search on http://www.ari.org you can find the rating of different matched systems.

We have installed alot of these systems in new homes and existing homes with upgrades needed to make the rating and insure comfort with lower cost than Lennox,Carrier.

[nathan9999]

Aircooled53

Thanks very much for the information on American Standard. I am awaiting a bid from a local AS contractor and this info will be helpful.

Doc,

Thank you for the recommendation. Part of the frustration is that I give the AC contractor the plans and I receive a bid without any of the communication and consultation that seems to be critical in making a good decision. I think the contractors assume I am shopping price alone, and I have been part of the problem as I haven't been as direct in letting them know that I want them to provide me with meaningful options about efficiency, comfort, filtering, etc. That will change right now.

Thanks again for your time and assistance.