New Furnace and A/C and finishing basement
I own a 2300 sq ft house in SE Pennsylvania and am in the process of finishing my basement (~700 sq ft) with the plans to heat/cool the basement with my central forced air HVAC system. I currently have a 13 year-old builders grade Lennox 3T A/C unit and 75K BTU single stage furnace. Recently, my coolant pipes and coils froze up on my central A/C unit due to low refrigerant caused by a coil leak. Given the leak (2 lbs added this year, 1 lb added last year), the rebates, and with finishing my basement, I thought it was time to get a new A/C unit and furnace while I'm at it.
I've had three contractors provide estimates so far and I have a few questions for this forum:
1) Two of the three contractors performed load calcs. One recommended a 91K BTU Lennox G61V furnace and another recommended a 71K BTU Lennox G61V furnace. If I am going to add 2-3 new supplies to my ~700 sq ft basement would a 71K two-stage unit suffice? Conversely, would the 91K unit be overkill (see question 2)?
2) The contractor who recommended the 91K furnace also recommended a 4T A/C. My 75K furnace and 3T units have worked perfectly to date, so why would I want to upgrade the A/C - especially if I'm adding supplies to the basement (which will probably remain shut in the summer)?
3) The contractor who did not do a load calc is recommending Whirlpool. I have never heard of a Whirlpool furnace or A/C and was wondering if anyone can address the quality and reputation of Whirlpool HVAC systems? It is by far the least expensive of the three quotes.
Thank you in advance!
A basement doesn't take much to heat or cool it. For heat though. It will never stay as warm as you want. Without zoning it. Since the heat will rise through the registers to the first floor during the off cycle.
So no real use in upsizing for the basement. No idea how that guy is coming up with an increase in size like that.
I agree, if the old system ran just fine what you had, there is NO reason to upsize!
Wonder if the dealer were entering in the wrong number or what not into the program. Ask to see the print out of the report.
Two stage would a good for comfort, and make sure you get a matching t-stat to control the system. not a basic single stage stat.
I'd recommend a multi-stage furnace w/variable speed blower and a 2-zone system. I'd also recommend you be careful about universal availability of parts. In other words, make sure the zone system you are given is not a product for which parts are not readily available down the road. Some manufacturer's make parts availability on their products difficult at best for non-dealers to purchase. You don't want to get painted into that corner.
Originally Posted by beenthere
If YOU want change, YOU have to first change.
If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!
Thank you so much. This is an outstanding forum.
For zoning, do you recommend the basement as one zone and the two upper floors as a second zone? Or would the top floor be a separate zone? How much does it typically cost to zone a system?
For heating the basement, I really wanted to aviod baseboard heat. I plan to use R19 insulation (plus R3 foam board already on walls as a vapor barrier) so it'll retain the heat. I figure on the really cold days we can just fire up a space heater in addition to having a few registers for forced air. Thoughts on this?
Finally any thoughts on Whirlpool?
If I'm not mistaken, Whirlpool equipment is made by Lennox? It's an off-brand, so less expensive than most others. Since the installer didn't perform a heat load, I'd recommend staying away. He's probably bidding low-cost equipment and a cheap install.
Zoning will vary in cost depending on the size and type of automatic dampers needed. They also will have to add additional thermostats and run wire so expect it to be a few thousand. If you're putting in a zone system I would suggest a 3 zone, one for each floor to be most effective. I highly recommended zone systems, they do wonders for multi-level homes! Try to stick with a main brand zone board like Honeywell or Aprilaire.
Is the contractor recommending a 4 ton A/C or Heat Pump? If he's talking about a 4 ton 2 stage heat pump that would explain the increase in size.
Originally Posted by TxTurbo
One contractor recommended a 4T A/C because that's what the load calc said it should be. He said 3T was not the right size for my 2300 sq ft house (although it has worked fine for 13 years). I'm going to stick with 3T.
The load calc should be similar to your past experience. Did the contractor ask what temperature you keep the home? If his design temps are different from where you actually keep it, that would explain the difference. If you want it to be 68 in the house you need a larger system than if you keep it 78. It also depends on how many people live there, if you have large groups of people over, etc.
Trust the contractor. If he recommends a larger system it may be because of other issues (air flow, heat gain, etc) find out what they are and if they'll affect you.
Originally Posted by dave78
I agree with you, if the three ton has done the job, stay with it. Besides, zoning will "stretch" the heat and A/C.
My first floor zone doesn't call often in the summer with the A/C, conversely, my second floor doesn't call for heat during the winter.
Right, you can go with a three zone system. They work well.
I did a lot of research on brands, features, manufacturers, etc. One of the results I found was that there seemed to be a few "odd birds" out there with not much information available. Whirlpool was one of them.
Originally Posted by dave78
Thanks everyone. This is great. 3T it is for the A/C. I am also shying away from Whirlpool...you're right, there isn't much info out there about it, so its near impossible to gauge the reliability.
I just had an offer from one of the contractors to upgrade the furnace to a two-stage 110K BTU with a 5T fan for free. Is it really "free" or will it wind up costing me more in my energy bill? Given I keep my house at 68 in the winter, do I really need this large of a unit (even if it's "free")?
He also said he recommends the single stage A/C unit as he said the two stage operation will "work against the second floor air delivery with the addition of the basement." Earlier he said the two-stage would remove more humidity...now I'm really confused. The SEER ratings on the Lennox XC14 and XC16 are nearly identical. Given I keep my house at 75 in the summer, is it true that the XC14 would be a better option for my house (2 stories + basement; 3000 sq ft total)?
Thanks again. Your insight has been great.
What's the model number of the furnace? If it's an SL series or G61V, it might be worth it. If it's just the G61 I would be wary of it. The difference is that the SL series and the G61V have variable fans capable of producing whatever air flow the system needs. Otherwise you run the risk of moving too much air over the coil and not properly cooling the house.
Are you looking into a zone system? If so, get the two stage system. Otherwise your contractor may be correct about it not being able to push air up to the second floor. I don't know since I haven't seen your duct system.
The XC14 is slightly quieter and the XC16 is two stage and slightly more efficient. If it were my house, I'd look into a zone system with the XC16.
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