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HVAC Comparison

Posted by kiropod (My Page) on
Thu, Apr 21, 11 at 7:39

I think that I've finally narrowed my proposals down to these 2.

Lennox 97% modulating gas furnace, 66,000 btu- model SLPUH070V36B
Lennox XP 17 3.0 ton heat pump
Lennox evap coil, model cx34
lennox touch screen iaq programmable thermostat
air plenum with Merv 16 filter with uv light set up
lennnox humidifier
condensation pump,

Carrier infinity furnace model 58mvc060f114 3 stage variable speed furnace
carrier performace 16 ser dual stage condensor, model 25HPA636
carrier evap coil CNPVP3617ATA
Infinity thermostat control
infinity air purifiier
honeywell large bypass advanced humidifiers

I did have a manual J and an energy audit performed. FYI, the Carrier proposal is $8,000 more. I know by looking at the specs that the Lennox heatpump is only a 1 stage, whereas the carrier is 2 stage.


Follow-Up Postings:

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RE: HVAC Comparison

Does the Carrier quote include the $1100 rebate? It is hard to believe the Carrier contractor wants $8000 more. Is there additional work being done?

Is the Lennox dealer proposing using a Merv 16 filter? I would be concerned about the increased static pressure. As the contractor about this. The static pressure reading should be in the 0.6-0.7 range. I am not sure if the Lennox thermostat gives this reading. I know the Infinity controller does.


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RE: HVAC Comparison

I would do the lennox quote. Thats nice equipment. Modulating gas furnace and xp17 heatpump are high end stuff. How much is that quote running you?


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RE: HVAC Comparison

Well. I will be getting 2 of each. The Lennox will be around $20,000 after rebates and NJ credit


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RE: HVAC Comparison

after crunching the numbers once again, the savings will be $4000 for the Lennox, not $8,000 Still that's a chunk of change. The Lennox had to be bumped up to an 80,000 BTU due to matching issues with the heatpump, but same price.


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RE: HVAC Comparison

What were the Manual J calulations for each floor?


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RE: HVAC Comparison follow up

The manual J recommended 60,0000 BTU furnace and 3 ton AC. The Lennox contractor stated that if we go with their 3 ton heat pump we must move up from their 66,000 btu to a 80,000 btu furnace, but since its a modulating furnace, it will likely never need to use that much energy. Does this make sense?


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RE: HVAC Comparison

Yes, it does make sense. Sounds like a nice system. How much square footage on each floor? So you decided to go with 2 different systems rather than one system zoned I see. Thats fine. Is this a new house or existing construction?


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RE: HVAC Comparison 3

Not sure what you mean by 2 different systems. We are going forward with the Lennox system, modulating 98% furnace and heatpump.


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RE: HVAC Comparison

I thought you mentioned in a previous post you would be getting 2 of each.


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RE: HVAC Comparison

2 different systems - you stated you were getting 2 of each. People often do a single system and zoning controls.

It might be worth considering a single system with zoning controls. It may not really be an easy option if this is existing construction. If it is new, it still might require extra work if you are underway.


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RE: HVAC Comparison

Yes, we are replacing our two furnaces (24 years old) and AC units. Its already set up for 2 zones. Thanks for your input.


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RE: HVAC Comparison

kiropod

this is NJ location?

one of the two furnaces is going to be located in the attic?

I would not place a condensing high eff furnace in the attic.

I think dual fuel(with heat pump) is overkill with a full modulating furnace.

But if you place an 80% furnace in attic, then I would pair with high eff HP.

IMO


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RE: HVAC Comparison

Both are in the basement.


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RE: HVAC Comparison

Did you look at the Manual J calculation? What was the calculated sizes for heating and cooling of each floor?

If find it hard to believe you need 6 tons of cooling for your house. I am not familiar with the Lennox furnaces. I think your choices are either 70,000 or 90,000 BTU input furnaces at 97% AFUE. It seems your contractor is recommending two 90,000 units or 180,000 BTU for your house. This also seems oversized.

Are you confident this contractor knows what he is doing?


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RE: HVAC Comparison

As noted before, the manual J recommended two 60,000 BTU furnaces and 2 3 ton AC's . The carrier quote (he did the manual J) included 3 stage variable speed 60,00 btu infinity 955 furnace with a 3 ton performance 16 ser dual stage compressor.

The Lennox quote is for a 90,000 btu fully modulating furnace. I did ask him about oversizing the furnace, but he said in order to match up the 3 ton heat pump, he had to jump up to the bigger furnace and since it is fully modulating, it will likely never need all 90,000 btu's. It's a large house with high cealings, etc.


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RE: HVAC Comparison

Do your heat pumps qualify for the NJ Cool Advantage rebate program. They need to be at a minimum of 16 SEER, 13 EER, and HSPF 8.5. If you do you will get $500 for each heat pump. Your furnaces qualify for the $400 Warm Advantage progam. Your total rebates would be $1400 assuming the contractor will submit the applications.


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RE: HVAC Comparison

Correction, the total would be $1800 for the two furnaces and heat pumps.


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RE: HVAC Comparison

The heatpumps are 17 SEER, 9.5 HSPF. Yes, he is going to submit this for us. Thanks mike_home


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