In Trouble Need 150,000 BTU's - HVAC - Page 4 - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 09-13-2010, 06:47 PM   #46
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by beenthere View Post
I didn't say to twin a mod.

I doubt his house really needs near as much heat as some of those contractors think/say it does.

Thursday, I was at a hose that had a Goodman GUN125-5 furnace. Sure did make that 2200 sq ft house warm. When it wasn't tripped on its high limit. oh, and it had a 2 ton A/C also. Sure did make for some hot air coming out of the registers.


My home has an old rickty 70% Bryant that's 125k!
five ton drive---bet only one side was of RA was tapped.
I betcha' that two ton had 2000cfm screaming thru it.

Advertisement

__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-13-2010, 06:52 PM   #47
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by Marty S. View Post
The Lennox guy is right. That's why I stated standard blowers in the first post because you can't twin v-drives or multi stage equiptment. If he's willing to put that guarantee in writing go for it. One G71 will be much cheaper then 2 furnaces twinned up front and in the long run.
Hey sumpin' ain't right!


We all agree on on the same solution
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-13-2010, 07:00 PM   #48
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,537
Rewards Points: 4,712
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by hvaclover View Post


My home has an old rickty 70% Bryant that's 125k!
five ton drive---bet only one side was of RA was tapped.
I betcha' that two ton had 2000cfm screaming thru it.
Only doing between 1117, and 1129 CFM(varied a bit by where I took static readings).

1 side for return(but a vaned ell). Plated off for the 2 ton coil. So all the air has to go through it(.45" PD across it), And a 28X8 main supply trunk.
beenthere is offline   Reply With Quote
Old 09-13-2010, 07:11 PM   #49
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by beenthere View Post
Only doing between 1117, and 1129 CFM(varied a bit by where I took static readings).

1 side for return(but a vaned ell). Plated off for the 2 ton coil. So all the air has to go through it(.45" PD across it), And a 28X8 main supply trunk.
HUH? That installer had his head in his back pocket. That trunk would have
been pretty nice for an 80K 90%.

That was the last of the 18ga steel heat heat exchangers.

Shoulda' walked out with furnace order on that one. Too many reasons not to. Too big -too old-too janitrol.

How was the ht ex.?
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-13-2010, 07:19 PM   #50
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,537
Rewards Points: 4,712
Default

In Trouble need 150,000 BTU's


Cracked. First cell has the flame jumping all around. 2 center ones both blowing back, and already cracked the from plate.

Gave him a price. But he is calling 3 other contractors in. Bet atleast 2 of them tell him he needs a 100,000 BTU 90%. ROFL
beenthere is offline   Reply With Quote
Old 09-13-2010, 09:06 PM   #51
Member
 
steveel's Avatar
 
Join Date: Sep 2010
Posts: 287
Rewards Points: 250
Default

In Trouble need 150,000 BTU's


Hey I found it. This Old House article in Sept 04 issue. Max Alexander states that HVAC contractors that do not do the time consuming load calc test for Manual J will likely guess at the size for the extreme days, and then ADD a large margin to be sure they don't get callback complaints. I'm replacing a furnace at my new house. I called several shops in town and they all said, "ahhh, you don't need a load calc, we can size you just by looking". A couple offered to *do* a jmanual calc if I paid them for the extra time (about $250 each). Money well spent, IMO.

But I guess the OP has heard "load calc" enough by now. Just be sure it is a REAL one, not a short cut one to make you feel good.

SteveEl
steveel is offline   Reply With Quote
Old 09-13-2010, 09:40 PM   #52
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Well Mr Alexander is out of his element or he would know that those "Long, drawn out calculation" can be done in about half an hour using soft ware and a lap top.

Another thing, templates can be made of same size homes for even faster results. Just add or subtract from the templates to solve for the home you are working in.

And then there are the guys who know their territory so well and have been in the biz so long sizing becomes intuitive. I am one those guys.

My bids and size selection of equipment is always in sync with competitors who can do a good load calc.

But to be fair, my market is a mostly guys who make a living with their hands and they expect a guy to be able to use his experience to size a home with out fancy electronics. That is the old country immigrant craftsman talking in them. And I agree.

I have been on bids where a competitor DID use a lap top. And he came up
with an 80k 95% furnace in a 1200sq ft split level that had new windows and added insulation in walls and attic spaces.

They offered me the job but they wanted the over sized furnace. I passed.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-13-2010, 09:50 PM   #53
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Rewards Points: 1,000
Default

In Trouble need 150,000 BTU's


Does the man J account for extreme days? Last I heard our design was 2 degrees. Heck I've seen looong stretches that didn't even hit 2 degrees for the high.
Marty S. is offline   Reply With Quote
Old 09-13-2010, 10:37 PM   #54
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


if your results say 5100k was good to 5*f, I always round up to a 60.
Because the line I use uses 20k increments. There is no 50k furnace in my line so you have to got to the next highest number.

You get one of those cold snaps with high winds .....well I don't want to have to pay for frozen pipes if the furnace breaks down from over burdening.

That is not adding a fudge factor, it's common sense.
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-14-2010, 04:40 AM   #55
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,537
Rewards Points: 4,712
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by Marty S. View Post
Does the man J account for extreme days? Last I heard our design was 2 degrees. Heck I've seen looong stretches that didn't even hit 2 degrees for the high.
Manual J uses 2% design criteria to determine load.

What area you in, city wise.
beenthere is offline   Reply With Quote
Old 09-14-2010, 07:54 AM   #56
Member
 
Join Date: Sep 2009
Location: Suburb of chicago
Posts: 195
Rewards Points: 152
Default

In Trouble need 150,000 BTU's


To Be continued in thread titled "200,000 BTU's part 2"
I printed all the pages from this thread, some 40 pages and I still don't know what to do?
turbomangt is offline   Reply With Quote
Old 09-14-2010, 12:50 PM   #57
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Sounds like the bids you got are not the ones you should consider.

Try somebody new but ask them if they have ever twined a system before you have them come out. If they have then ask them if they would use a Variable speed motor or a two stage system. If they says yes, hang up and try somebody else.

Push come to shove you can't get a qualified guy send a PM to me or Been. We will try to put you in contact with someone who knows what to do.

Good luck turbo
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-14-2010, 01:20 PM   #58
Member
 
Join Date: Sep 2009
Location: Suburb of chicago
Posts: 195
Rewards Points: 152
Default

In Trouble need 150,000 BTU's


"ask them if they would use a Variable speed motor or a two stage system. If they says yes, hang up and try somebody else."

Yes to which?
turbomangt is offline   Reply With Quote
Old 09-14-2010, 01:47 PM   #59
Member
 
hvaclover's Avatar
 
Join Date: Oct 2008
Location: Suburbs of Detroit Mi
Posts: 3,704
Rewards Points: 2,000
Default

In Trouble need 150,000 BTU's


Quote:
Originally Posted by turbomangt View Post
"ask them if they would use a Variable speed motor or a two stage system. If they says yes, hang up and try somebody else."

Yes to which?
To both.

I thought we had this al sorted out, but ok, I'll give you the short version

Do not use a contractor who would use a two stage furnace (they all come with Variable speed motors) also do not use any other furnace with a variable speed motor period.

Before you have someone come out, call around and tell the Pro you ned a twined system. Let them tell what furnace they would use. When he tells you what furnace, just ask if they are two stage type furnace with a variable speed blower. If he tells you they do have VS blowe go to the next guy.

The point is you don't want a VS blower on a twinned. Like the one guy told you they would never be in sync which is bad for your duct system performance wise.

If you can't find any body to do the job right then PM one of the pros here and we will try to find somebody near you to help you out.

We good now?
__________________
Just slow, not stupid.
hvaclover is offline   Reply With Quote
Old 09-14-2010, 03:42 PM   #60
Member
 
Join Date: Sep 2009
Location: Suburb of chicago
Posts: 195
Rewards Points: 152
Default

In Trouble need 150,000 BTU's


yes, you guys are great............

Advertisement

turbomangt is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas Furnace: How many btu's for 1500 sqf? lloydb HVAC 12 08-20-2010 04:28 PM
Trouble removing T&P Valve from water heater secutanudu Plumbing 3 04-07-2010 06:35 PM
Btu's and watts Steelhead Electrical 11 01-04-2009 07:23 PM
Help! Circuit breakers in trouble Circuit breakers Electrical 9 12-22-2008 01:58 PM
trouble fitting 4 wires into three demondope Electrical 11 12-28-2007 12:58 PM




Top of Page | View New Posts