Picking Gas Furnace

camiarrobino

Hello, wondering if anyone can provide their opinions on these gas furnaces. I am considering replacing my oil furnace (this is my first home with forced hot air instead of hot water so I am not as up to date with different furnace brands compared to boilers) and have gotten several proposals with the following options:

HEIL 95%
Bosch 96%
Amana green sky 97%
Amana green sky 92%
Concord 96%
Run tru by trane 95%

all of them shall be 60k BTU as my house is about 900 SF

pecmsg

60K sounds large for 900 sq ft. 

Where is this house?

camiarrobino

pecmsg said:

60K sounds large for 900 sq ft. 

Where is this house?

Boston suburbs. There are a few other considerations. I may utilize the furnace in the future to heat the basement if I finish it. Also, we have central air paired with this system, and the outside unit is 2.5 tons and inside is 3 tons. These are staying as is. I understand this is way oversized, but my understanding is that we need a 3 ton blower for the central air to work properly. I believe that the next size down furnace of 40k BTU would not have a 3 ton blower

pecmsg

I would look at a Heat Pump with a hot water coil as a back up. A small boiler could supply the HW if / When needed!

camiarrobino

pecmsg said:

I would look at a Heat Pump with a hot water coil as a back up. A small boiler could supply the HW if / When needed!

Don't want a heat pump, I want a gas furnace (and that's if I even abandon the oil furnace, which is 12 years old and works fine).

In terms of DHW I also just had an IBC gas wall-hung on demand unit installed 6 months ago. Our gas bill is like $10 a month and that is for DHW and cooking. 0 reason to make any changes from a DHW perspective

pecmsg

You might want to start doing a little research. 

Rebates
tax advanteges
no more gas hook ups
there are a lot of advantages 

Hot_water_fan

I see no reason not to go 40kbtu and/or a heat pump. They can easily be combined in a hybrid system. 

None of this sounds right

but my understanding is that we need a 3 ton blower for the central air to work properly. I believe that the next size down furnace of 40k BTU would not have a 3 ton blower

jesmed1

Hot_water_fan said:

I see no reason not to go 40kbtu and/or a heat pump. They can easily be combined in a hybrid system. 

None of this sounds right

but my understanding is that we need a 3 ton blower for the central air to work properly. I believe that the next size down furnace of 40k BTU would not have a 3 ton blower

Isn't the OP's point that the furnace blower needs to be able to move enough CFM (400 cfm per ton AC as a rule of thumb) to handle the cooling load? So a 3 ton AC unit like the OP has needs a furnace blower that can move 1200 CFM. And too small a furnace may not be able to deliver that CFM.

We have a similar setup at our church where the HVAC company installed a furnace that ended up being too large for the existing ductwork. I suspect one of their reasons for the oversized furnace was that, under normal circumstances, the blower CFM would have been high enough to handle our 3 ton AC.

In our case, the furnace ended up being too big for the small ducts and overheating as a result, but that's another story.

pecmsg

jesmed1 said:

I see no reason not to go 40kbtu and/or a heat pump. They can easily be combined in a hybrid system. 

None of this sounds right

but my understanding is that we need a 3 ton blower for the central air to work properly. I believe that the next size down furnace of 40k BTU would not have a 3 ton blower

Isn't the OP's point that the furnace blower needs to be able to move enough CFM (400 cfm per ton AC as a rule of thumb) to handle the cooling load? So a 3 ton AC unit like the OP has needs a furnace blower that can move 1200 CFM. And too small a furnace may not be able to deliver that CFM. We have a similar setup at our church where the HVAC company installed a furnace that ended up being too large for the existing ductwork. I suspect one of their reasons for the oversized furnace was that, under normal circumstances, the blower CFM would have been high enough to handle our 3 ton AC. In our case, the furnace ended up being too big for the small ducts and overheating as a result, but that's another story.

At 900 sq ft 3-Tons is huge!

jesmed1

pecmsg said:

At 900 sq ft 3-Tons is huge!

LOL. I didn't say he needed it...but now that he has it, without enough airflow the coils may freeze, no?

mattmia2

Some studying of the catalogs is in order. There are usually models with a larger cabinet and smaller heating output to accommodate climates with big cooling loads and small heating loads. That being said, unless you're running a commercial kitchen, pulling 3 tons out of 900 ft^2 house is never going to work well.

pedmec

Sounds like he only wants to do the furnace and not the coil. He only needs 1000 cfm's as the condenser is only 2.5 tons. Sure it's not ideal and he will have to deal with humidity issues and short cycling but unless he downsizes he will have to live with what he has.

My recommendation would be an America Standard furnace as they are well built and supplied by S G Torrice. Tech support is in the neighborhood (wilmington).

pecmsg

jesmed1 said:

At 900 sq ft 3-Tons is huge!

LOL. I didn't say he needed it...but now that he has it, without enough airflow the coils may freeze, no?

900 sq ft needs 1-Ton 1 1/2-Tons tops!

pecmsg

pecmsg said:

jesmed1 said:

At 900 sq ft 3-Tons is huge!

LOL. I didn't say he needed it...but now that he has it, without enough airflow the coils may freeze, no?

900 sq ft needs 1-Ton 1 1/2-Tons tops!
unlessyiur in the Deep South with no windows!

jesmed1

pecmsg said:

pecmsg said:

jesmed1 said:

pecmsg said:

At 900 sq ft 3-Tons is huge!

LOL. I didn't say he needed it...but now that he has it, without enough airflow the coils may freeze, no?

900 sq ft needs 1-Ton 1 1/2-Tons tops!
unlessyiur in the Deep South with no windows!

Yes, he has oversize equipment. Now he needs more oversize equipment to make the other oversize equipment work right.

offdutytech

I would ask the contractor if the did a load calc on the house. Assuming the size is correct are any of the units a two stage or modulating gas valve? If so that's why they may have selected a 60k for its balance between heating low fire and cooling CFM balance. 
Heil: Carrier product shares parts with Bryant and Carrier furnaces 
Bosh: Don't have any experience with them
Amana: Daikin product like Goodman
Concord: Lennox product pressed heat exchanger and not tubular like other manufactures. (not really a fan)
Trane: Sold to companies that are distributors. Parts might be a hassle to get in the future if a Trane OEM part is needed. 

Often times equipment can be a regional thing and different equipment lines may not be for sale because of territories.  For example in my area you have to buy into being a Bryant distributor, but I can buy parts for them. Lennox same thing, but I can easily buy a Concord. We sell Luxaire, but if I wanted to sell Coleman I would need to buy into the distributor and sell a certain dollar amount. Funny thing is both Coleman and Luxaire are the same furnace with a different plastic badge on the unit. For a while during the past few years the both those furnaces came without the plastic badge and the supply house would just hand you the right badge to put on.

Point being is that there are only a few major equipment manufactures out there anymore and they just have different lines based on region and sales network. With any furnace you go with you want a competent contractor who will size the equipment and make sure the ductwork is also correct. 

mattmia2

Modulating or 2 stage is a good idea to address the oversizing if you don't want to fix that on the ac side. Is there any chance this will be more economical than keeping the oil furnace?

Hot_water_fan

Isn't the OP's point that the furnace blower needs to be able to move enough CFM (400 cfm per ton AC as a rule of thumb) to handle the cooling load? So a 3 ton AC unit like the OP has needs a furnace blower that can move 1200 CFM. And too small a furnace may not be able to deliver that CFM.

This is what the OP thinks, but it is wrong. You can get a blower that gives you 1000 CFM for cooling AND runs at a lower speed for heating. Or just use 1000 CFM for both. They make two stage 40kbtu high, 28kbtu low furnaces, that could actually use 3 speeds, 2 for heating, 1 for cooling. Contractors should know how to do this. These are basic units.