A few questions for those in the know

[uncleblaine]

Originally posted by Christheheatingdude

Originally posted by anonymous
fill in some information about you in your profile. We don't like diy's trolls here. you will have to call a professional.

Is this who I think it is?

Well my weblogs say the first visitor after putting my url in the profile was from Florida, if that helps. But several more have visted from Georgia, California and Connecticut. I'll refrain from offering anything more specific. Statcounter is a wonderful thing for those of you who have websites... and it's free.

Anyway, I appreciate all the input you guys have offered. I'll be spending some time reading up on those sites, and will download the calculator tonight. My wife recently did an excercise appraisal on our house so I'll have many of the measurements handy.

Of the folks I've called, the Bryant contractor and the Carrier/Trane (yep, that's what they carry) contractors both have sterling and long reputations in the area. The Rheem guy is less well known, but will try to check things out further if he seems a likely candidate.

I'll keep you posted and if I can get through the calculator tonight I'll post my results.

Thanks again!
Blaine

[mlbussert]

Sorry, I can't help you as I am a HO myself in the process of buyin a new AC/Furnace, and I have found the people in this site very helpful and knowledgeable so that I can make a decision as to which contractor to go with.

However, I have to comment that I could not stop laughing since I find it highly ironic that someone with the username "anonymous" would ask you fill out your profile.

[uncleblaine]

Ain't that the truth!

If you're still looking for info, check out the hphaa.com link ct2 posted. Incredible information!

I many times will highlight a line of text to use as a page mark when I'm called away from the computer. Was taken aback when it wouldn't work. Then I thought about it a bit more. VERY smart call!



[Edited by uncleblaine on 10-08-2005 at 06:18 PM]

[uncleblaine]

Okay, I've done the manual J, and here's the whole house results if anyone is interested.

With current windows:
S/Gain L/Gain T/Gain T/Loss
15596 3417 19013 53612

With new windows, patio door and front door:
14659 3417 18076 47427

That's just shy of 6200 BTU less heat loss. To me that seems quite substantial, but I'm a laymen. And in all actuality, the only changes made in the program were to lowE glass, and vinyl frame. The old windows leak like seives so the real difference may be greater.

Back to studying recommended links...

[Irascible]

Originally posted by uncleblaine
I many times will highlight a line of text to use as a page mark when I'm called away from the computer. Was taken aback when it wouldn't work. Then I thought about it a bit more. VERY smart call!

Well... not really. I was trying to protect my content. But you have no idea how easy it is to circumvent the no highlight/no right click feature. I'll let you figure it out on your own. ;^)

[uncleblaine]

Originally posted by Irascible Well... not really. I was trying to protect my content. But you have no idea how easy it is to circumvent the no highlight/no right click feature. I'll let you figure it out on your own. ;^)

LOL Actually, I do, but at least it keeps most honest people honest. I've been through that a bit myself. I'm just happy to read the info, I don't want to "borrow" it.

I imagine there's at least a few less than upstanding contractors who aren't pleased with your truth-speaking. Kudos to you for doing it. Excellent information!

[dash]

Originally posted by uncleblaine
Okay, I've done the manual J, and here's the whole house results if anyone is interested.

With current windows:
S/Gain L/Gain T/Gain T/Loss
15596 3417 19013 53612

With new windows, patio door and front door:
14659 3417 18076 47427

That's just shy of 6200 BTU less heat loss. To me that seems quite substantial, but I'm a laymen. And in all actuality, the only changes made in the program were to lowE glass, and vinyl frame. The old windows leak like seives so the real difference may be greater.

Back to studying recommended links...

Imporovements saving 5% on cooling,and 11% on heating.

That's like buying a half of SEER more ,and going from an 80 to a 90 % furnace.

[uncleblaine]

Originally posted by dash
Imporovements saving 5% on cooling,and 11% on heating.[

That's like buying a half of SEER more ,and going from an 80 to a 90 % furnace.

Well hopefully doing the a 90+ furnace and several SEER on the AC can save that much again. Perhaps I need to hope for cold winters and hot summers so I can have a quicker payoff.

[dash]

Originally posted by uncleblaine

Originally posted by dash
Imporovements saving 5% on cooling,and 11% on heating.[

That's like buying a half of SEER more ,and going from an 80 to a 90 % furnace.

Well hopefully doing the a 90+ furnace and several SEER on the AC can save that much again. Perhaps I need to hope for cold winters and hot summers so I can have a quicker payoff.

Don't forget the higher utility costs more likely than the weather changing that much.

[dan sw fl]

Originally posted by uncleblaine
Okay, I've done the manual J, and here's the whole house results if anyone is interested.

With current windows:
S/Gain L/Gain T/Gain T/Loss
15,596 3,417 19,013 53,612

With new windows, patio door and front door:
14,659 3417 18,076 47,427

That's just shy of 6200 BTU less heat loss. To me that seems quite substantial, but I'm a laymen. And in all actuality, the only changes made in the program were to lowE glass, and vinyl frame. The old windows leak like seives so the real difference may be greater.

Back to studying recommended links...

Blaine,

Why would you have existing 100,000 BTUh capacity and
53,612 BTUh need per your analysis ?

I believe your have performed analysis which does
not show Total BTU loss.
Infiltration is a huge contributor to this difference.

Say house is 30 x 50 x 20 foot tall = 30,000 Cubic feet
Using a "Quite LOOSE" value 0.6 ACH yields
~ 300 CFM infiltration.
Q= CFM * dt * 1.08
1.08 = constant

Q= 300 CFM * 81 'F dT * 1.08 = 26,400 BTUh
Estimated Current Load
26,400 + 53,600 = 80,000. BTUh MAX ( 81 'F dT)
Of course, review of heating energy bill would be quite useful at this point.

You could obtain infiltration of 0.25 ACH or 125 CFM with
new windows and significant caulking / spray foam effort.

Q net savings = 175 * 81 * 1.08 = 15,309 BTUh
at design temp of -11'F
----------

WINDOWS
Q= U * A * Dt
U= 1.0 for Old perhaps
U= 0.3 for New ? ONLY As an example

A (Total window area) might be 200 Sq.Ft per floor
Dt = -11'F + 80 = 81'F

Qnew windows = 0.3 x 200 x 81 = _4,860
Qold windows = 1.0 x 200 x 81 = 16,200

Energy Savings per 200 Sq. Ft.= 11,340 BTUh
---------------

I would expect > 20,000 BTUh total savings given this
set of ASSUMED values ( adjust as appropriate)
which may "get you in the ballpark"
of a Energy Saving$ goal.

Perhaps, purchase of a ~70,000 BTUh 90% efficient furnace
(63,000 BTUh NET)
is what you may be able to pursue with integrated improvements in housing Envelope AND Heating equipment.

[uncleblaine]

Hi Dan,

Why would you have existing 100,000 BTUh capacity and
53,612 BTUh need per your analysis ?

I don't know. I questioned it too, but just used the software. Of course it was my first time. Infiltration is listed at 15956 BTUH total loss. Perhaps I should run through my entries to see if I've made a major gaffe. I'll also try plugging my measurements into your calcs to see what I arrive at.

edit to add

Infiltration numbers are shown as .4 summer and .7 winter, on 2752 square feet. This is using average/loose construction figures built into the software.



[Edited by uncleblaine on 10-09-2005 at 11:53 AM]

[Freezeking2000]

I am wondering if during the coldest windy nights did your existing furnace EVER run for 30+ minutes?

I know that when -20F with 30 MPH winds the heating equipment get a good run. You do not want to be short capacity in Minn. when temps drop below design temp. I would get a 2 stage system so the heat will run constantly and go to high fire when exreme temps hit.

Also I hear the 90+ units are not as reliable, but I hat be incorrect since I am a Refrigeration man. I do know you cant go without heat for more than a few hours in Minn.

Ask the contractors what they recommend for the severe winters you have! They are the ones that have to make it work on the cold winter night when it is -20.

[uncleblaine]

Originally posted by Freezeking2000
I am wondering if during the coldest windy nights did your existing furnace EVER run for 30+ minutes?

I know that when -20F with 30 MPH winds the heating equipment get a good run. You do not want to be short capacity in Minn. when temps drop below design temp. I would get a 2 stage system so the heat will run constantly and go to high fire when exreme temps hit.

Also I hear the 90+ units are not as reliable, but I hat be incorrect since I am a Refrigeration man. I do know you cant go without heat for more than a few hours in Minn.

Ask the contractors what they recommend for the severe winters you have! They are the ones that have to make it work on the cold winter night when it is -20.

You know the more I think about it, the more I'm wondering if the units are oversized, and perhaps the ducting undersized. To be honest I've never really paid attention to how long the furnace runs in any given cycle, but I'm going to start now. And oversized or not, the two-stage has been in the front of my mind for a more even temp and its comfort, if no other reason. That would also make my air cleaner do its job better. Though 2 of 5 animals have passed on since that was put in, so it already has less work to do.