New Lennox Installation vs New Goodman

[Frogger42]

Hi all this my first post after stalking the forums for a bit. I live in Dallas Texas and am remodeling my 1,200 sf home built in 1940. As you can imagine all my windows are single pane wood frame, this house is brick and it gets quite toasty in the summer. We are adding ~300 sf downstairs (to the 1,200) and building 1,000 sf upstairs. We need a new HVAC system for the upstairs and downstairs.

I'm familiar with Goodman's products and naturally was inclined to lean towards the DSCX16 for its 16 seer rating (efficiency), tax rebate, and warranty.

My contractor's HVAC sub uses Lennox products and bid on the assumption we would use the Lennox branded products

My contractor's HVAC quote includes the following equipment for a lennox system:

2 ea L190UH36A-070 gas furnace
2 ea CH33-36A evaporator coil
2 ea 14ACX036, 14 SEER, 3 ton A/C
2 ea Pro-6000 thermostats

The quote detailed a certain amount for the cost of the above equipment, which I was surprised (the $ was much lower than I would have expected) I am not sure if this was a result of assumed Dealer incentives from the June Lennox promotion. Please PM me, because I would like to know thoughts about the cost and what a similar setup using the Goodman units should cost in my area.

Does this system sound like a good fit for the proposed remodel? Is it worth it to upgrade to a more efficient system for tax/dealer rebates, higher quality equipment and lower utility bills? I am not sure what the cost to upgrade would be.

Thanks in advance for any advice you can offer.

[George2]

Hi all this my first post after stalking the forums for a bit. I live in Dallas Texas and am remodeling my 1,200 sf home built in 1940. As you can imagine all my windows are single pane wood frame, this house is brick and it gets quite toasty in the summer. We are adding ~300 sf downstairs (to the 1,200) and building 1,000 sf upstairs. We need a new HVAC system for the upstairs and downstairs.

I'm familiar with Goodman's products and naturally was inclined to lean towards the DSCX16 for its 16 seer rating (efficiency), tax rebate, and warranty.

My contractor's HVAC sub uses Lennox products and bid on the assumption we would use the Lennox branded products

My contractor's HVAC quote includes the following equipment for a lennox system:

2 ea L190UH36A-070 gas furnace
2 ea CH33-36A evaporator coil
2 ea 14ACX036, 14 SEER, 3 ton A/C
2 ea Pro-6000 thermostats

The quote detailed a certain amount for the cost of the above equipment, which I was surprised (the $ was much lower than I would have expected) I am not sure if this was a result of assumed Dealer incentives from the June Lennox promotion. Please PM me, because I would like to know thoughts about the cost and what a similar setup using the Goodman units should cost in my area.

Does this system sound like a good fit for the proposed remodel? Is it worth it to upgrade to a more efficient system for tax/dealer rebates, higher quality equipment and lower utility bills? I am not sure what the cost to upgrade would be.

Thanks in advance for any advice you can offer.

The first thing that really jumps out is the 6 tons for 2,500 sq ft.

I would think (without doing a Manual J) a 2 ton for each floor would be more like it.

The equipment is secondary. I've got a bad feeling for your general contractor's choice of a HVAC installer.

[Frogger42]

Thanks for the advice. How do i politely inquire whether or not a manual J has been performed and whether or not two 3 ton units are appropriate?

[George2]

Thanks for the advice. How do i politely inquire whether or not a manual J has been performed and whether or not two 3 ton units are appropriate?

Very few (contractors) will take the time to do a Manual J, so don't be surprised, when you bring it up, that they will give you some song and dance as to why it's not necessary.

Check with your power provider. Quite often they will do it for a small fee.

Or, if you look at the top of this page you'll see a place you can click and do your own.

[ampulman]

The first thing that really jumps out is the 6 tons for 2,500 sq ft.

I would think (without doing a Manual J) a 2 ton for each floor would be more like it.

The equipment is secondary. I've got a bad feeling for your general contractor's choice of a HVAC installer.

What jumped out at me was the 2 x 70K furnaces. Using 60K here across the river from Philly in NJ.

[George2]

What jumped out at me was the 2 x 70K furnaces. Using 60K here across the river from Philly in NJ.

Oversizing the heat won't have the affect as oversizing the A/C. I don't if the furnaces mentioned are 80% or 90+% AFUE.

The next size down might only be 45,000?

[Frogger42]

Thanks all for your spot-on advice. I would like to be as informed as possible when I go back to the HVAC subcontractor, so I don't get yanked around. I performed a Manual J and the results point to MUCH overcapacity with two 3ton units.

I have a few followup questions for the community:
1. I am calculating 34,452 total cooling load, is that in the ballpark of a two story remodeled brick 2,300 square foot home?
2. Given the total cooling load of 34,524, what system would you reccommend (not brands or pricing, just the size and specs)?
3. What is the disadvantage/advantage of having two smaller systems vs. one larger system?

Thank you so much in advance for any help you can offer. I greatly appreciate it!

[RoBoTeq]

Oversizing the heat won't have the affect as oversizing the A/C. I don't if the furnaces mentioned are 80% or 90+% AFUE.

The next size down might only be 45,000?
You will care about the heat being oversized when your new furnace heat exchangers fail due to too many short cycles creating condensate issues.

[beenthere]

Oversizing the heat won't have the affect as oversizing the A/C. I don't if the furnaces mentioned are 80% or 90+% AFUE.

The next size down might only be 45,000?

2-45,000 BTU furnaces should be plenty for 2500 sq ft in Texas.

[Frogger42]

Roboteq, thanks for popping up. Any advice for a two story (is this a multi-zone?) system that requires ~35,000 btuh cooling load?

[beenthere]

Thanks all for your spot-on advice. I would like to be as informed as possible when I go back to the HVAC subcontractor, so I don't get yanked around. I performed a Manual J and the results point to MUCH overcapacity with two 3ton units.

I have a few followup questions for the community:
1. I am calculating 34,452 total cooling load, is that in the ballpark of a two story remodeled brick 2,300 square foot home?

Varies with the remodel.

2. Given the total cooling load of 34,524, what system would you recommend (not brands or pricing, just the size and specs)?

Depends on the indoor and outdoor design temps that were used.

3. What is the disadvantage/advantage of having two smaller systems vs. one larger system?

Thank you so much in advance for any help you can offer. I greatly appreciate it!

With 2 systems, if one breaks you still have the other one, so you can sleep in a air conditioned area at night if a tech can't make it out right a way.

[Frogger42]

With 2 systems, if one breaks you still have the other one, so you can sleep in a air conditioned area at night if a tech can't make it out right a way.

Now that is a VERY good point. Thanks Beenthere!

[BaldLoonie]

Your typical 2500 sq ft home here in Indy would have 1 70K furnace and 1 3 ton A/C and cool and heat great. We already have been 95 and steamy and the winters can get below zero. So, sizing of both heat & cool stand out to me as considerable. Are they not insulating the new work or something?

I wouldn't be polite about it, I'd demand a very accurate manual J and asked to see it. Oversized will haunt you both seasons. Noisy, inefficient, summer humidity issues...

[RoBoTeq]

Roboteq, thanks for popping up. Any advice for a two story (is this a multi-zone?) system that requires ~35,000 btuh cooling load?
There are several ways you can go. If you go with two systems, a two ton system for the upper floor will do most of the work if you have a 1.5 ton system installed on the first floor running when the first floor needs a bit more then what is dropping from the second floor. The second floor system would run for long cycles, allowing for good dehumidification. In this case, the least amount of heat as possible would be best. I would even say a two ton heat pump for the second floor and a 1.5 ton cooling system on a 45k Btu furnace for the first floor would be good.

If you go with a single system, a variable speed blower is a must. With a 34K cooling need, a 42K system should work well in your area due to the latent cooling need required for dehumidification. Actually, whenever there is a need for dehumidification, a variable speed blower is recommended (run at a lowered cfm rating).

[George2]

There are several ways you can go. If you go with two systems, a two ton system for the upper floor will do most of the work if you have a 1.5 ton system installed on the first floor running when the first floor needs a bit more then what is dropping from the second floor. The second floor system would run for long cycles, allowing for good dehumidification. In this case, the least amount of heat as possible would be best. I would even say a two ton heat pump for the second floor and a 1.5 ton cooling system on a 45k Btu furnace for the first floor would be good.

If you go with a single system, a variable speed blower is a must. With a 34K cooling need, a 42K system should work well in your area due to the latent cooling need required for dehumidification. Actually, whenever there is a need for dehumidification, a variable speed blower is recommended (run at a lowered cfm rating).

No offence RoBo....but......
2 ton for 1,000 sq ft.!? Recommend:1 1/2 ton up and 1 1/2 ton down wit 45,000 btu furnace (95% afue) or 70,000 btu (80% afue)

[RoBoTeq]

No offence RoBo....but......
2 ton for 1,000 sq ft.!? Recommend:1 1/2 ton up and 1 1/2 ton down wit 45,000 btu furnace (95% afue) or 70,000 btu (80% afue)
No offense taken. Pay better attention, please. I specifically stated that by putting the 2 ton system on the upper floor that it would wind up running most of the time conditioning the entire house because of air stratafication. Because it will be conditioning nearly the entire house, it is not oversized at 2 ton capacity.

[George2]

No offense taken. Pay better attention, please. I specifically stated that by putting the 2 ton system on the upper floor that it would wind up running most of the time conditioning the entire house because of air stratafication. Because it will be conditioning nearly the entire house, it is not oversized at 2 ton capacity.

I did catch that and I definity understand your thinking. EXCEPT, I think there will not be the stratafication that you think there will be.

I think a 1.5 ton would run more (on both floors) and dehumidify better. IMHO.

But I'm a one system guy anyway. I would install a 2 ton and zone the home.
I have a 2,250 sq ft 2-story (built in 1946) with a 3 zone system and 2.5 ton A/C. No problem. I honestly think a 2 ton would do my house now that I have the zoning.

[RoBoTeq]

I did catch that and I definity understand your thinking. EXCEPT, I think there will not be the stratafication that you think there will be.

I think a 1.5 ton would run more (on both floors) and dehumidify better. IMHO.

But I'm a one system guy anyway. I would install a 2 ton and zone the home.
I have a 2,250 sq ft 2-story (built in 1946) with a 3 zone system and 2.5 ton A/C. No problem. I honestly think a 2 ton would do my house now that I have the zoning.
Why would stratification not occur? Do you know something about this house not being affected by the laws of physics that the rest of us do not know?

And how do you come up with 2 ton? What is it that you know about this particular house that the rest of us don't know? I cooled a 1,750 square foot house built in the 1700s with a 1.5 ton system, but that don't mean that it can be done in every house.

Why would you prefer a single zoned system over two completely seperate zones using two seperate systems? Zoning has it's place, but if you can use multiple systems for zoning, it is always better for when one system is not operational.

[George2]

Why would stratification not occur? Do you know something about this house not being affected by the laws of physics that the rest of us do not know?

And how do you come up with 2 ton? What is it that you know about this particular house that the rest of us don't know? I cooled a 1,750 square foot house built in the 1700s with a 1.5 ton system, but that don't mean that it can be done in every house.

Why would you prefer a single zoned system over two completely seperate zones using two seperate systems? Zoning has it's place, but if you can use multiple systems for zoning, it is always better for when one system is not operational.

I thought you knew that I was physic.........lol. I have no proof, but I would think if the downstairs is cool and dry, I don't see were the stratification comes in to play.
Anyway, you're making me work too hard. I re-read the post and I see he is practically rebuiling the house. He doesn't have a second floor system (ductwork) now so yes a new system upstairs would make sense.

[RoBoTeq]

I thought you knew that I was physic.........lol. I have no proof, but I would think if the downstairs is cool and dry, I don't see were the stratification comes in to play.
Anyway, you're making me work too hard. I re-read the post and I see he is practically rebuiling the house. He doesn't have a second floor system (ductwork) now so yes a new system upstairs would make sense.
George2, why are you not a professional member here? You don't have to worry about your ID or any information sent to the Membership Committee. Once a decision is made for Professional Member applications, all information is deleted.

You are missing out on a lot, and from your posts, it looks like other pros can learn a thing or two from you as well.