AC/Heat guys What Brand of Furnace to buy?

[whatsupdoc]

Building a new home in climate zone 5, two floors and a walk out basement somewhere around 2600 square feet.
Heat will be propane forced hot air with AC. I know oil hot water systems fairly well but know squat about propane forced hot air.
So I need some schooling.

What brands should I look at?
What efficiency rating?
Does higher efficiency mean more issues?
Vertical vs horizontal mounting, does it matter?

Any other tips that you can provide.

Thanks

 

[diverdon]

Honestly I like radiant heat more than forced air. I have a Weil McClain ultra boiler and a WM ultra + hotwater tank connected to it.

I do have a furnace because (when I put it in) as long as you're installing central air then it was only another 1200 to install a cheap furnace for backup.

A big plus is that your hot water is effectively limitless, you'll come to appreciate that once you have it.

When we travel during cold weather we set the boiler thermostats to 60 and the furnace thermostat to 50. Then if the boiler goes into some weird fault mode our pipes don't freeze.

As I only use the furnace a few days a year I don't care about efficiency. Just make sure you get a good blower with it so you're central air is reliable. I set a monthly reminder to Change the filter.

 

[rjacobs]

whatever you put in...

SPRAY FOAM EVERYTHING...

 

[missed]

I will ask some of the guys that I know. We put a Rheem in this house, its been running great for 6 years on normal maintenance. 14 SEER cool, 90% propane furnace. Looking back I wish I would have gone 2 stage cool, and 2 stage heat with heat pump as the first heat stage. Even with the energy prices sky rocketing last time I looked the 18 SEER cool is about the break point on saving any money within the 20 year lifecycle. I went 14 SEER for the super simple control systems. No exotic circuit boards to die or have the supertech with the computer to have to work on. My buddies place has a Trane with the full variable speed inside and outside 22 or 24 SEER, lightning killed both circuit boards and the variable speed drives. It was almost $12k to replace the 4 components and was about 6 months for the parts.

This house is all spray foam, 3200 ft with a 5 ton unit with 3 zones. I have to run the other 2 zones at 25% open to add enough load to the system to have it not short cycle in the spring and fall. Even this summer when it was 110 the unit is still slightly oversized. The variable speed compressor would be nice.

I have wanted to experiment with a 3 phase induction compressor and variable frequency drive and be able to slow the compressor down to approximately 30hz at the minimum drive compressor speed off the differential temperature from the line set. All the residential variable speed compressors are permanent magnet motors which require different drives, and the motors are 2-3x the price of induction. At that point I could use common VFD's and a PLC to drive it all.

 

[fpgt72]

We have propane for our house, and "old school" AC. Had to replace it a year or so ago, the first system lasted 22 years, from day 1 of the house.

We got a Trane, I don't remember off the top of my head the costs. Propane also does our hot water but nothing else. Our propane use seems to have gone down with the new system, we are on a "keep full" with the propane guys so they are out roughly the same time, everyone on our road uses them, the gallons are smaller, we have a 500gal tank. New AC we can keep at a lower temp then the old, and the bill is also lower.

When we shopped we looked at all the big names, It was something I just could not force myself to learn about so the wife did all of it. One of the things about ADHD is that hyper focus part, I researched new toilets for 3 months and only the wife saying she is sick of going down stairs to go to the bathroom did I make a decision, I just could not learn about heat and AC.

We chose ours for the "rebates" through our local gas and electrical suppliers, Trane just had the best deal. When the wife was talking they are pretty close to the same specs and costs.

 

[rjacobs]

When I replace all this builder grade forced air junk in my house I am doing ductless mini-splits everywhere... Likely Daikin.

But heat is not as big a priority for us here in Texas as it is up north so heat pump based mini split units generally work down to -5(at least as advertised).

 

[xsn10s]

We have a Goodman heat pump and it's been pretty good for Eastern Oregon zone 5. I think I'd get a Trane, they seem to be of higher quality. I'd love to have propane, NG, or a wood pellet stove to augment the heater but just use the electric heater when temps get too cold. I also use kerosene heaters as an emergency/ addition heat on really cold days.

 

[Threadcutter308]

I will ask some of the guys that I know. We put a Rheem in this house, its been running great for 6 years on normal maintenance. 14 SEER cool, 90% propane furnace. Looking back I wish I would have gone 2 stage cool, and 2 stage heat with heat pump as the first heat stage. Even with the energy prices sky rocketing last time I looked the 18 SEER cool is about the break point on saving any money within the 20 year lifecycle. I went 14 SEER for the super simple control systems. No exotic circuit boards to die or have the supertech with the computer to have to work on. My buddies place has a Trane with the full variable speed inside and outside 22 or 24 SEER, lightning killed both circuit boards and the variable speed drives. It was almost $12k to replace the 4 components and was about 6 months for the parts.

This house is all spray foam, 3200 ft with a 5 ton unit with 3 zones. I have to run the other 2 zones at 25% open to add enough load to the system to have it not short cycle in the spring and fall. Even this summer when it was 110 the unit is still slightly oversized. The variable speed compressor would be nice.

I have wanted to experiment with a 3 phase induction compressor and variable frequency drive and be able to slow the compressor down to approximately 30hz at the minimum drive compressor speed off the differential temperature from the line set. All the residential variable speed compressors are permanent magnet motors which require different drives, and the motors are 2-3x the price of induction. At that point I could use common VFD's and a PLC to drive it all.

Unless the (PM) motor is a proprietary mounting pattern, you ought to be able to use a standard NEMA pattern AC Induction motor. That will also allow you to use a "plain brown wrapper" VFD/Inverter. Much less expensive for either/ both components.

 

[ironman56]

I replaced my all electric central AC myself here in Central Texas , the old one was from the 1980's ,so over 30 yrs old 2 ton unit , i got a qoute of 9k from a local ac contractor, but since I'm pretty handy ,I decided to tackle the job myself. Went with Goodman brand , the reviews were good and the airhandler was one of the only ones that would fit in the existing closet, and I didn't want to tear out walls and ceiling to modify for a larger one , total cost was 3100.00 and that was with new copper lines , so a big savings, time will tell if I made the right choice, but , others In my neighborhood have the same brand and have had good results.

 

[DarnYankeeUSMC]

ICP. International Comfort Products.
92% efficient is what I install.
Heil
Carrier
Arco air
Payne
And a few more names are basically all the same. Ten year warranty on all parts.
I wouldn't put a Trane in if it was given to me. Over engineered POS.
My.02 for being in the business for over thirty years

 

[chevy_man]

I have kept the cheap Goodman that came with my house (natural gas).

So far the only thing to not fail has been the control board.

I put in a new vent blower motor, new primary fan motor, flame sensors and thermocouple are yearly maintenance items....

Only reason I didn't buy anything else, is I know a furnace guy who treats me good on parts. He also carries generic control boards that I can use on this old furnace and not be waiting 6 months on a board from Trane.


If I was designing a new house I'd do a boiler, and electric forced air for AC and backup heat. Mostly because it's dirt cheap to get an electric furnace and if the power is out the furnace isn't running anyways.

 

[xsn10s]

ICP. International Comfort Products.
92% efficient is what I installed.
Heil
Carrier
Arco air
Payne
And a few more names are basically all the same. Ten year warranty on all parts.
I wouldn't put a Trane in if it was given to me. Over engineered POS.
My.02 for being in the business for over thirty years

Good to know about the Trane. I meant Carrier but hey I'm open to anything from a pro's stand point.

 

[missed]

Unless the (PM) motor is a proprietary mounting pattern, you ought to be able to use a standard NEMA pattern AC Induction motor. That will also allow you to use a "plain brown wrapper" VFD/Inverter. Much less expensive for either/ both components.

They are all hermetic so the motor and compressor is mounted in the can. I know very little about Copeland scroll compressors, plenty of experience with screw and centrifugal. Oil flow and heat removal is potentially going to be an issue with running at lower speeds. The refrigerant is what cools the motor in the hermetics. That is one of the big reasons a compressor will die if it is system is low on refrigerant as it can not cool off. They may use PM motors so there is 100% torque available at all speeds, where the induction motor can not do that.

 

[Threadcutter308]

They are all hermetic so the motor and compressor is mounted in the can. I know very little about Copeland scroll compressors, plenty of experience with screw and centrifugal. Oil flow and heat removal is potentially going to be an issue with running at lower speeds. The refrigerant is what cools the motor in the hermetics. That is one of the big reasons a compressor will die if it is system is low on refrigerant as it can not cool off. They may use PM motors so there is 100% torque available at all speeds, where the induction motor can not do that.

Ahhh.......the hermetic thing. That greatly complicates things, particularly from a cost reduction perspective.

An AC Vector drive and motor can provide 100% torque throughout the entire base speed range, but the downside is extra cost and an encoder on the motor.

It may be that you are stuck and will have to go with the PM motor..,,..

 

[Marinevet1]

I've got a high efficiency Trane that's been a pretty good unit, but will never buy another one as long as they keep putting that Christmas tinsel looking condenser coil in them, pain in the ass to keep clean.