HVAC Questions? Ask an HVAC Expert for Answers ASAP
Hello there! I'm Norman but you can call me Norm. Let's see what I can do to get you some answers today. I'm ready to get started whenever you are.
Hope you are doing well!
Doing well thank you...
I have looked through all of my Carrier data and I only see where the 4 tons air movement at 400 cfm per ton can be achieved with a 90k furnace but its output is 71k
I'd like you to see for yourself.
What does that mean...my old furnace is 75,000 btu
I would like 75,000 btu again,,,,,
If you copy and paste that in your address bar you can click on any of the 80 percent furnace is, when the page pulls up simply click the word physical data on the right hand side
Is 75,000 btu on the invoice from 9 years ago states 75k
what that means is the furnace will have a rating of 90,000 BTU's but only output 71,000 because it is 80 percent efficient.
My invoice from 20 years ago state 75k btu......therefore the output is less
With an 80 percent furnish you only get 80 percent of the heat
Does your invoice say 75,000 BTU input or output?
They did not write output.....when you by a furnace do they state 90 k btu and not disclose the output
Yes they tell you it is a 90,000 BTU furnace at 80 percent efficiency. They do disclose this information in the product data.
My question is carrier doesn't sell 75 k or 80 k....with a 4 ton
you have to accept 90 k but
My concern is that it will have a extra burner created too much rapid heat, therefore heating up the house quicker?
Your best bet would be the 58DLA090–1-16 With 88k input and 71k output and is capable of handling for tons
Since the far back room is extremely cold and very far from the thermost...and therefore the heat will turn off two quickly because of the hotter air...and not heat up the back room
My question is about the difference between a 75,000 btu and 90,000; how will this effect my given situation
It will heat up faster and satisfy the heat setting quicker and it may also dry the air out quicker. Possibly moving the thermostat closer to the back room may help but I without a doubt would seriously consider the 2stage 58CTA
I am trying to get the exact unit I had for the past 20 years, since the heat distribution was perfect. Since my back room is very cold and the thermostat is in the front of the house. I am concerned that 90,000 btu will produce hotter air, and not staying on to allow the air to move to the back room. Will the 90,000 btu produce extreme hot air compared to 75,000btu
It will run at I think 44k then ramp up as needed. The larger furnace will not produce hotter air it will just warm more air quicker.
You have a very valid concern. I've been in the business for 17 years and I would put my vote on the 2 stage...seriously.
I'm also a mechanical designer and estimator in both commercial and residential.
I hold unlimited hvac license in two states so I promise I'm not just blowing smoke.
If the blower is blowing out at a constant speed, the hot air will move exactly the same. Should the extra burner of 90k produced more volume of heat...therefore the heat coming from the vent will be hotter?
If the 4 ton from carrier made a 75,000btu this would solve the problem....
should i go with a different make...
Go with a company that makes a 4 ton with 75,000 btu
I sell York and Trane myself.
does there 4 ton come with 75,000 btu
We put in both. Both have great equipment and American STD makes Trane
Let me look
which company has 4 ton with 75,000 btu
Is there a big difference between 75,000 and 90,000 btu....meaning if the house is going to heat up faster; and, the fan is at a constant speed on both the 75 k and 90 k; there must be hotter air coming out of the 90 k to heat up the room faster.
Ok the York TM(8,L)X100C16MP11 comes in an 80k with an output of 75k so that's closer.
that is a 4 ton?
Yes 4 ton at 1600 but nominal.
1600 cfm, sorry lol
Page 2 list all the specs
Is there a big difference between 90k and 75 k
If you worked fine and felt great at 90k then yes it can be a big difference. It's like oversizing an air conditioner by 1.5 tons.
I'm sorry I meant at 75k
We sell more York's than anything.
Great product with a great warranty. The old timers will say differently because they use to have a bad reputation.
WARRANTY20-year limited warranty on the heat exchanger.10-year heat exchanger warranty on commercial applications.Standard 5-year limited Parts warranty
Extended 10-year limited parts warranty when product isregistered online within 90 days of purchase for replacement or closing for new home construction.
I have a contractor installing the carrier in the morning....will have to call and stop..
the contractor told me there is no difference
Do you suffer from dry sinus now?
The house will be dryer or will it be dryer quicker....
The house will be warm more quickly....just how much more quickly...1 minute....5 minutes...
Well, you may not see the effects as much as others can who suffer. It's something that's like rolling the dice. He may be right in saying you will be fine but you won't know until the furnace is installed. Something to also think of is that most systems are sized in tonnage for A/C and the furnace kind of comes along secondary to that. How many sqft is your home?
There are so many factors that I couldn't venture a guess, that's very scientific and I don't want to feel you a line.
feed you a line, sorry
1750 sq ft
the 4 ton seem to be ok for the past 20 years....
Mine is 1900 sqft and I have a 60k
Is the house well insulated?
how many ton
is the 3 ton more important than the 60k.....
I want you to know that 90% of contractors oversize heating and cooling systems because they have no clue how to size and select equipment. That's a fact.
A/C is always your #1 when sizing a system but with a split gas system you get to also consider heating. With a heat pump you don't have that luxury. You size for cooling and get what you get in heating.
Maybe i just do not know any better....since the 4 ton has been there for 20 years...it felt really good. Maybe it should work better....but i would never know...
I told the 30 years experience heating contractor to give me exactly the same....everything is the same except the 75k is 90k
I put in a 2 ton on a 1700 sqft house just about 6 months ago. It had a 4 ton before we did the job. The customer swore we were wrong and told us it was going to be removed and replaced at the first sign of discomfort. Well....they love the 2 ton now.
The contractor isn't supposed to listen to the homeowner. He's supposed to size it to his best ability and walk away if a homeowner demands a certain size. That's part of holding a license.
I understand...do i pay more for energy with a 4 ton...
how does it work less effeciency...
I will tip you 20%
If after running a calc the system is determined to be oversized then yes, you pay more.
since this is taking longer
What do you set the thermostat to in A/C mode/
Will it still heat the house the same...just less effecient'
I don't even sell 80% furnaces any more. Only offer the 90%
The termostat is the controller...
You are basically telling the contractor I'm going to pay you 100% of the bill to give me 80% of the furnaces ability to heat.
What temperature do you set the thermostat too in A/C mode?
Maybe i am putting to much thinking between the 75k and 90k
There is no air....I am on the ocean...
I'd either get a 2 stage furnace or a modulating furnace which willl ramp up and down based on demand and run time. I'd also be going with a 90% if I were you.
It sounds like the 4 ton is more of an issue than the 90k
No, I'm going to back up. I was thinking you had a 4 ton a/c system connected to this as well. That's why you were asking for 4 tons.
4 tons for just a furnace is the volume of air it moves at what speed.
Not btu's of cooling. See when you have a/c with the system you would use a 4 ton furnace with a 3.5-4 ton A/C unit.
4 ton produces the speed of moving the hot air??
Volume in Cubic feet per minute (cfm)
Is this the job of the fan
the duct size connected to it determines the velocity or speed
fan moves the hot air
4 ton produces??
BTU is the burners producing the heat
I'll be honest with you. I would let the man install the furnace. Make sure he is giving you a satisfaction guarantee. Let it run for a month or so and see how it does. He can always speed up the fan or slow it down to make minor adjustments to the heat rise of the furnace.
so, what does 4 ton mean again..
4 tons is hvac talk for 1600 cfm
its a nominal term
What give me a comfort level is that you sale mostly 90 k ...
So if I said 3 tons that is 1200 cfm (400cfm per ton)
I'm sorry, I'm not understanding that question.
I see...so my house will heat up faster with 4 ton...
and with 90k...and you mostly sale 90k...
I sell 90%
90% efficient furnaces
you get 90% of the heat delivered to the space not lost in the attic or basement.
a 90% furnace is a much better option.
with 4 ton....do you sale 75k 80k or 90k...
Couple that with 2 stage or modulation and you've got a killer system.
how do you determine which one to sale a customer
The answer would be... it depends on the load calculation of the space. Every home is different.
He talked me out of the two stage because
We evaluate every single house we do. We do Heat loos and heat gain calcs before we select any equipment, every single time.
the slower stage one would move the air slower and the heat would turn off before it reached the back room...
Do you have dampers in the main ducts?
He stated the two stage; the first stage would move air very slow...
Are these 2 separate duct runs?
they go in different direction...from one main duct run
So you could have two dampers installed, one on each direction, which you could use to make adjustments to how much air goes where?
back to the original question; the extra 15 k btu will not make the house dryer....just dryer more quicklyu
drying and warmer more quickly...
You ask some very technical questions, lol.
If I were you I would be doing what I can to get the two rooms straightened out, weather it be zoning or dampers.
because of the thermostat...the house will not be hotter....will not be dryer....is will just happen faster
The house won't be hotter because the thermostat will kick it off when it hits the set point.
It shouldn't be too much dryer if any.
prefect...therefore my only risk is the unit shutting of before it warms the back room...but....more volume of air will travel back there...so the difference will be minor...
And you can make adjustments to the fan speed and see how it affects the space.
last question....if i place my hand on the vent...
the 90k will not be hotter than the 75k....
or the hotter air will be very minor
It should not be because the installer should be increasing the air speed to keep the same temperature rise across the heat exchangers.
If any it will be very minor, maybe 5 degrees
I am not clear....
I commend you on answering sooo many questions....
The slower the air passes across the furnace the hotter the air will be. If he speeds it up the air will not get as hot.
thank you for communication so clearly..
Not a problem. I try to be thorough.
that is good to know...
i will make sure...he can compensate for the appr...5 degree.
Yes, he can speed it up.
that is really good to know....
You are very welcome and best wishes. I'm very glad I could help you! If you ever need help in the future please bookmark my personal link and visit me again. I'd be glad to help. http://www.justanswer.com/home-improvement/expert-its-norm/. Thanks in advance for the positive rating and have a great night!
enjoy the evening ...until next time
You as well.