Need some HVAC guidance (furnace flue venting)

[rbstern]

What a screwed up contractor not to mention HE furnaces ahead of time. 2" PVC in and out the sidewall is the way to go. Try to get it changed back weven if you need to send the units back, if you can. HEs are more expensive though but have a neat installation/

It hasn't been his best moment, that's for sure. He's good at other stuff, even very good. Has a great eye for site elevation issues, framing, roofing and finish issues. His weakness seems to be mechanical systems, and we're suffering a bit for it. In the case of electrical, it didn't matter, because the electrical sub was first class and caught a few issues, or responded very professionally to our input. They were experts interested in doing the job right. The HVAC vendor was interested in doing the least amount of work possible, with the least amount of communication. It's led to these problems.

 

[Sigarms]

Propane. Not dual fuel. We'll supplement with fireplace during the couple of months of actual "winter" we have here in GA. We are pretty frugral with dinosaur-fueled heat (use an electric blanket, programming the thermostat for night/away, etc.). We spend more on AC than heat in these parts.

In Atlanta Georgia, there are more heating hours than cooling hours. I'll stand by my assesment that if you're on LP and spending money on a gas furnace for some type of heating with LP, a dual fuel system would be a better ROI assuming you're electric has a better rate than your LP for heating above 30 degrees.

With newer systems, they generally use less energy if always running. A programable t-stat does not save you any money if you're temp swings are greater than 2-3 degrees.

That said, you're the customer and the one spending the money, so as long as you get what you want, that's all that matters

Got to ask, what are you spending on your fireplace? If it's a decent fireplace that actually transfers heat into the home instead of up the chimney, not sure why you just didn't go straight heat pump per HVAC system?

 

[BrokeFarmerJohn]

As far as the botched duct, there is different types of duct you can install so it doesn’t hang so low or impede a low basement ceiling. With duct work it really needs to be as direct as you can, the more 90s in a run to a register off the main truck really lowers the airflow.

But it can be ran in wider but shorter duct so it doesn’t hang as low, they make oval pipe for diffuser runs that keep clearance under at a maximum, easier to hide in a drop ceiling etc.

As far as the flue being angled, it has to be that way, flue pipe condensates a good amount of water, that water has to travel back to the furnance. PVC handles water better than metal but if slopped enough, should be ok for a while, more than 10 years, maybe 30 idk.

Trane is ok, I’m not a fan of them, they are old technology, they haven’t updated there equipment as much as carrier and Lenox has. My fav is prob Rheem, they are simple to work on, they seem to be really reliable and just work. Lenox 2 stage furnance with a variable speed blower is nice, it ramps up slow, doesn’t create duct work flex, runs at the speed that’s needed vs a set speed.

But I have a love hate relationship with Lennox, every furnance that stumps me and I call hateful names to seems to be a Lenox every time lol. Idk why

If it was my place, I would do the work myself but I would prob install a Rheem HE furnance paired with a heat pump and topped off with a smart stat, I have a Honeywell 8000 on my wall, I can set parameters for the heat pump to run till the outdoor temp gets to 32, after that the furnance runs, saves on utilities and no colder drafty type environment inside. I guess manufacturers are saying to run heatpumps down to 0 degrees, at some point you are trading dollars of savings for wear and tear on the equipment. What that threshold is idk. And I would most likely do a concentric out the back of the house. It’s not a eye sore, not something people notice and much easier to do vs roof in some cases, I have mainly put in roof concentrics.

 

[Wilco]

I'd fire the HVAC contractor and hire a new one. If they don't know what they're doing the system will never work properly and you'll never be comfortable. Tell them to gather up their s*** and get out. Have the new contractor remove the equipment, repair the ductwork and install high-efficiency furnaces... the federal rebates make going with high efficiency units a no-brainer.

 

[rbstern]

In Atlanta Georgia, there are more heating hours than cooling hours. I'll stand by my assesment that if you're on LP and spending money on a gas furnace for some type of heating with LP, a dual fuel system would be a better ROI assuming you're electric has a better rate than your LP for heating above 30 degrees.

We pay about 15% per kwH more than average US electricity prices. We pay about 5% less than average for LP.

Last house I had with a heat pump used electricity as emergency heat source. It was very expensive to run in cold weather. Dual fuel might have made sense, but other than knowing I didn't want electric heat, I didn't get into the specs with the contractor. And I should have. Or insisted on an HVAC vendor I trusted; didn't know this one would be such a screw up.

With newer systems, they generally use less energy if always running. A programable t-stat does not save you any money if you're temp swings are greater than 2-3 degrees.

Not sure I understand that. If I have my thermostat set to 68 during occupied hours, and 60 during sleeping or away hours and it cuts down substantially on furnace run time, how can it not save $$$. We're talking about long stretches (8 hours) with substantially reduced usage. Yes, it has to recover, but hard to imagine how 30 to 60 minutes of recovery time uses more energy than saved during the many hours it didn't run when at the lower setting.

That said, you're the customer and the one spending the money, so as long as you get what you want, that's all that matters

Got to ask, what are you spending on your fireplace? If it's a decent fireplace that actually transfers heat into the home instead of up the chimney, not sure why you just didn't go straight heat pump per HVAC system?

Can't answer that at the moment. Opted for a large box with good reviews for performance, similar to one we had experience with at our previous home. I have pretty much unlimited firewood, and the fireplace is in the house's great room, centered where it will provide heat to much of the living spaces. Previous experience with a similar fireplace and central location in the last house was that the fireplace easily added a couple of degrees to the main living space and reduced the load on the furnace.

 

[rbstern]

I'd fire the HVAC contractor and hire a new one. If they don't know what they're doing the system will never work properly and you'll never be comfortable. Tell them to gather up their s*** and get out. Have the new contractor remove the equipment, repair the ductwork and install high-efficiency furnaces... the federal rebates make going with high efficiency units a no-brainer.

It may come to that, but keep in mind I don't have a contract with the HVAC contractor. My contractor does. And I have a contract with him. Yes, I can jump up and down, get red in the face, make funny noises, yell obscenities, but ultimately, there are contracts in place between the various parties, which define who gets what. It's not as simple as saying "I'm mad as **** and I'm not going to take it anymore!" Wish it were.

 

[rbstern]

As far as the botched duct, there is different types of duct you can install so it doesn’t hang so low or impede a low basement ceiling. With duct work it really needs to be as direct as you can, the more 90s in a run to a register off the main truck really lowers the airflow.

Here's a laugher: We went with an open truss system for the floor. There are clearly some places where ducts could have been run in the trusses, and they are hangered below. Like I said: It's a vendor that just didn't care.

That will all get corrected.

Trane is ok, I’m not a fan of them, they are old technology, they haven’t updated there equipment as much as carrier and Lenox has. My fav is prob Rheem, they are simple to work on, they seem to be really reliable and just work. Lenox 2 stage furnance with a variable speed blower is nice, it ramps up slow, doesn’t create duct work flex, runs at the speed that’s needed vs a set speed.

But I have a love hate relationship with Lennox, every furnance that stumps me and I call hateful names to seems to be a Lenox every time lol. Idk why

Have Trane in another house. Like it. Had 2x Lenox in my previous home. Mostly reliable, but some fussiness over the years. Have had several Goodmans in rental properties I owned, and they proved to be extremely reliable.

If it was my place, I would do the work myself but I would prob install a Rheem HE furnance paired with a heat pump and topped off with a smart stat, I have a Honeywell 8000 on my wall, I can set parameters for the heat pump to run till the outdoor temp gets to 32, after that the furnance runs, saves on utilities and no colder drafty type environment inside. I guess manufacturers are saying to run heatpumps down to 0 degrees, at some point you are trading dollars of savings for wear and tear on the equipment. What that threshold is idk. And I would most likely do a concentric out the back of the house. It’s not a eye sore, not something people notice and much easier to do vs roof in some cases, I have mainly put in roof concentrics.

I'm comfortable with electrical, some carpentry and plumbing, certain types of finish work. Have never really done HVAC, which caught up with me this time.

 

[Sigarms]

We pay about 15% per kwH more than average US electricity prices. We pay about 5% less than average for LP.

Last house I had with a heat pump used electricity as emergency heat source. It was very expensive to run in cold weather. Dual fuel might have made sense, but other than knowing I didn't want electric heat, I didn't get into the specs with the contractor. And I should have. Or insisted on an HVAC vendor I trusted; didn't know this one would be such a screw up.



Not sure I understand that. If I have my thermostat set to 68 during occupied hours, and 60 during sleeping or away hours and it cuts down substantially on furnace run time, how can it not save $$$. We're talking about long stretches (8 hours) with substantially reduced usage. Yes, it has to recover, but hard to imagine how 30 to 60 minutes of recovery time uses more energy than saved during the many hours it didn't run when at the lower setting.

My head was on heat pumps since I'm in a 85% heat pump market. You hit the nail on the head with using strip heaters and why it cost so much. A heat pump nowadays should only use strip heaters to heat unless it's below 30 nowadays. Know more than a couple sub 18 SEER systems that can kick out out over 105 degree air discharge temperature down to 10 degree outside air without the use of strip heaters.

 

[BrokeFarmerJohn]

Im comfortable with electrical, some carpentry and plumbing, certain types of finish work. Have never really done HVAC, which caught up with me this time.

Their isn’t a guy out there that knows every trade well. HVAC, electrical, residential maintenance and some plumbing is as far as my knowledge goes, I don’t know what most of the codes are to pass inspection, only know some HVAC codes here locally. My point is don’t beat yourself up too bad, whole point of general contractors lol.

I have done work for a few GC, same with inspectors they can be hit and miss, architects botch stuff up more than anyone lol on job sites, either the plumbers, electricians or HVAC guys got screwed each time, if not done in the right order, one would be in the way of the other etc, stuff has to be moved, pulled down till the other guy was done or scrapped and redone all together, it happens.

Poor electricians always had to move there stuff, they would get all there devices in, instantly in the plumbers way, or the conduit was in the HVAC guys way lol, so they had to pull it down and re route conduit etc.

I’m sure everything will work out for you.

 

[rbstern]

I’m sure everything will work out for you.

Thanks for the encouraging words. It's frustrating, but nobody is dead or dying, no epidemic has broken out, no nukes have been launched. The house will still get done.

In other words, it's a 1st world problem.