Time For a New Furnace

[william8]

Ok Willem I understand. The variable speed blower wouldn't compensate?

If the blower can not get enough air, it will run faster. The blower will ramp up to try and force air through the small ducts, causing it to be loud and potentially "hunt" (speed up and slow down) as it can't achieve the required airflow.
And new furnaces require ECM motors. VERY expensive to replace.

 

[Chetlaham]

Chet, have you had your current furnace heat exchange inspected?? Is the rust from that?

The rust is from the evaporator coil raining down the side and interior of the furnace.

 

[Chetlaham]

He wants to increase his BTU 4x, that would require bigger ductwork:

Many houses could benefit from larger ductwork, but the cost on an existing structure is prohibitive.

My heat is already oversized by about 3-4x.

I said I like it that way, not that I want to increase my current 100,000 BTUs to 400,000 BTUs.

The AC on the other hand is to small, need a 2x from the current.

 

[vacerator]

Chet, I would keep it if it is safe to use and save the expense of a new furnace until it is shot. It will take years to recoup the energy savings over the up front cost of a new one.

 

[Chetlaham]

Is that enough? Another science denier...

Not everything is a conspiracy. Honest mistakes and ignorance are enough. Class J isn't perfect to obsessed with dancing around equilibrium even though it is born out of good intentions. But being honest I like class J. You can take the final numbers and multiply them by a good safety or comfort factor and you're all set.

 

[william8]

My heat is already oversized by about 3-4x.

I said I like it that way, not that I want to increase my current 100,000 BTUs to 400,000 BTUs.

The AC on the other hand is to small, need a 2x from the current.

You only require 25K BTU? How tiny is the house? Like I said, mines only 60K, and the return duct is much larger, so is the filter. 2000 sq ft, very cold climate. Design temp is -10f for heat

AC is 2 ton, and slightly oversized, they don't make a 1.7 ton, which is what the manual J showed. Works fine.

 

[phillymatt53]

I know there are members on here, including myself who are frequently accused of making off topic comments or veering a thread off course when the replies are not succinctly in parallel with the OP's question.

However I myself do not see oil, gravity or hot water heat as being off topic in relation to this thread. Perhaps my definition of being tangential is far more liberal than that of others. It is interesting and educational to know the life expectancy of different types of systems and their behavior in relation to forced hot air. The knowledge gained from this can help better my system, and it is comforting to know that I am not the only one experiencing hiccups despite having a different type of heating system.

Vacerator, I don't mean to raze you. You're been nice and you've always liked my posts when no one else has. I should do the right thing and reciprocate. You are a very friendly forum contributer.

Just wanting to say that I don't mind comments about oil, gravity, steam, hot water or other types of heat

When in person with several people, say, at a dinner party, it's natural to wander with topics, because sometimes things come to mind that cause another to bring up perhaps a similar subject.
It's Human Nature, not unusual or purposly disruptive.
It's the way humans are.

 

[Chetlaham]

When in person with several people, say, at a dinner party, it's natural to wander with topics, because sometimes things come to mind that cause another to bring up perhaps a similar subject.
It's Human Nature, not unusual or purposly disruptive.
It's the way humans are.

Much indeed, and what might seem tangential or off topic to some is actually interconnected with the subject matter. Just as mentioning time and mass after space was brought up 200 years ago at a university might seem widely extraneous when today we know mass, time and space all have a profound relationship with one another.

 

[william8]

Not everything is a conspiracy. Honest mistakes and ignorance are enough. Class J isn't perfect to obsessed with dancing around equilibrium even though it is born out of good intentions. But being honest I like class J. You can take the final numbers and multiply them by a good safety or comfort factor and you're all set.

More conspiracy. And it's Manual J, the questions below would answer if it was done correctly. It's not guessing, or opinion based.

So what was the static pressure on the commissioning report when they installed the furnace? What was the Delta T for AC, what was the heat rise?
Hard to offer advice when someone won't give the required information. How big is the home, what's the climate?

 

[phillymatt53]

Being overly obsessed about something that is natural for humans to do creates problems and unrest of others.
Discussions over the internet are not different from a couple of guys sitting on the back porch, talking.
In fact, if several in a group become the type to regularly criticize or put down others, they're labeled.
Yes, websites have rules, and should be respected, but nitpicking over trivial things gets boring.

 

[neptunebob]

The longest lasting furnace is a boiler

Houses with hydronic hot water heat will not need a new boiler for at least 30 years. My sister had a 90 year old house and the second boiler was installed in 1948, the previous boiler was coal and this one is gas. Not all that efficient but as of yesterday it still heated when it was cold.

So Chet, buy a house with hot water heat, start the day with a fiber drink and you will be much happier in life.

By the way, don't have too big an air conditioner if you live in a humid area, you will feel icky when the oversize machine cools the temperature down but does not take the time to remove the humidity.