carrier infinity -vs- rheem modulator

[pagirl]

Which would you recommend for Butler(near Pgh) PA?
I got a quote for the roughly the same price with these perameters:
Rheem has double the warranty and includes Mod tstat.
Infinity includes non-progammable tstat.
Do I need an infinity tstat? My installer said no.

Is a 7"x24" return drop to my furnace sufficient to run 1 of these systems at 75,000 btu with 2.5 ton a/c?

Contractor says yes. But if you read my other posts, others have said no. Another contractor wants expand the return drop to 8"x25". That doesnt seem much of a difference, or is it. Another contractor wants to expand my return drop to 16"x24". That seems overkill, or is it?

My return air returns dont seem to pull any air. I did the tissue test. This contractor said that he felt it was a blower problem, and when the new equipment is installed it will most likely take care of it. Is this possible?
The other Rheem installer wants to look into the ductwork in the basement. He feels he can fix the problem by doing this, but couldnt tell me how. He also said that he would not put in a Rheem modulator because of the returns not working.

Lastly, I did like the contractor I talked to today, but I am not opposed to suggestions by you all. If you recommend a contractor in my area that is competitive in price, and can tell me if my ductwork is good let me know.

Hopefully with your advise I can decide which contractor to go with.

Thanks again. You all have really helped me more than you know!

[dash]

The Bald one and Doc,on this site ,tell me the Mod is the tops for comfort in a Gas furnace.
So I have to say go heat pump and use the Infinity,just kidding!!


I'd get the Mod or Infinity "control" whichever one you end up buying.

Infinity -advantage in cooling and if a heat pump.
Mod -advantage in gas heating.Wow,that wasn't as hard to type as I thought it would be.LOL

The return drop sizing depends on all the rest of the ducts in the home,the total resistance(external static pressure ),of all of them determines actual sizes.That said a 7or 8 X 24 is likely on the small side.They really need to analyze all the ducts,to know what should be done.


Unless some here can point you to a great contractor,I'd call around and tell them up front ,the following;

I want:
1.A manual J load calculation to determine the correct size system.

2.A manual S to select the equipment,and a Man. D analysis of the ducts ,to size them correctly.

This will eliminate a lot of contractors and the ones that can do this are the better ones,may not be the lowest cost but well worth it in the long run.


Is (pgh) the Burg ,if so call this site's very own Diceman.


[Edited by dash on 10-11-2005 at 02:16 PM]

[Jultzya]

2.5 Ton system needs 1000 CFM.

75K 90% at 50 F Delta needs 1250 CFM

7x24 equal to roughly 800
8x25 equal to roughly 1000

10x24 is roughly 1400

16x24 roughly 2800 You sure he wasn't talking filter size?

Lastly, I did like the contractor I talked to today, but I am not opposed to suggestions by you all. If you recommend a contractor in my area that is competitive in price, and can tell me if my ductwork is good let me know.

If you are looking for "good" and "cheap", forget it. Most of the time they fight each other.

[pagirl]

I am not looking for cheap. I am looking for good and honest. I obviously know very little about the subject. I am just not sure if I found a contractor I trust. In fact you may have answered 1 of my questions. It looks as if I should be leaning toward the contractor who wants to expand the duct 16"x24". That may be a bit much but the others are not enough.

I am interested in having someone come in and determine why the air returns dont work and try to fix it at the same time as the install. I thought one of the contractors who came to my house would be able to do this. Most say with new equipment it will fix itself.

Do you have any contractor recommendations.

[pagirl]

I also told my contractor that I wanted a media air filter. He plans on using the existing Honeywell electronic air cabinet and putting the media filter in that. Instead of buying all new. No other contractor suggested doing this. Does this make sense?

[BaldLoonie]

From a heating standpoint, the Mod has comfort nothing can touch. It's like being in a car. You can throttle the heat back when the car warms up or if it is mild out. You don't just have an on-off switch. Or in the case of the Infinity, a high-low-off switch.

The Mod can do dehumidify on demand with a separate control but doesn't have near the capability of the Infinity control, something beneficial in hot, humid climates.

To me, the whole Infinity vs Mod boils down to climate. Up north, Mod. SE to Texas humidity, Infinity.

[Jultzya]

Originally posted by pagirl
Most say with new equipment it will fix itself.

That's like saying; "if I install a new engine the body will look like new again".

Problems don't resolve themselves.

Tell them you are not interested in new equipment. Tell them you are interested in a system that will provide you years of service while providing comfort and savings.

[pagirl]

I was told the Carrier has a DC motor which is beneficial since it runs the whole time. Does the Rheem modulator? If not, how much more energy does it use.

The contractor wants to use a white-rodgers 1 stage thermostat with the infinity.

[Edited by pagirl on 10-11-2005 at 03:57 PM]

[smadave]

The contractor who wants to put the white rogers tstat on your infinity furnace.....throw him out of your house

All variable speed motors are DC motors regardless of manufacturer.

Good Luck!

Dave in NJ

P.S The motor doesn't necessarily run all the time.

[captainrat]

call an american standard dealer

[BaldLoonie]

Originally posted by captainrat
call an american standard dealer

Why? They have nothing to compete with the Mod nor the Infinity system.

[Christheheatingdude]

Originally posted by pagirl
I was told the Carrier has a DC motor which is beneficial since it runs the whole time. Does the Rheem modulator? If not, how much more energy does it use.

The contractor wants to use a white-rodgers 1 stage thermostat with the infinity.

[Edited by pagirl on 10-11-2005 at 03:57 PM]

I would insist on the infinity control. Silly to let all that furnace can do go to waste with a single stage stat.

[mayguy]

The Rheem Mod uses the varaible speed blower..

Dump the carrier dealer if he won't use the infinity t-stat on that system.


I'd go Rheem if I were you.