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

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-24-2013, 05:41 PM   #46
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,411
Rewards Points: 0
Share |
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by FixitDragon View Post
1dB is the smallest incriment, or change in sound, most people can decern
3dB incriment is double the sound energy, but NOT what we perceive as double the volume. (This is where some confusion comes from) In audio terms, it takes twice the power to increase the sound by 3dB, but we do not perceive 3dB to be twice as loud, only somwhat louder
10dB incriment is an order of magnitude more sound energy (10x), and what we perceive as "twice as loud" In audio, it takes 10x the power to make something twice as loud.

In terms of ACs, you will notice some difference between 74,70, and 66, the 74 will seem about 75% louder than the 66. Don't pay a bundle to gain 3dB for something that sits outside, air handler is a much larger factor for the noise in the living spaces.

(yea, I am an engineer )
I disagree somewhat. If it sits on his patio then sound is an issue and worth spending $$ on and if it is outside a bedroom window and can be heard then it is worth spending $$ on a quieter unit IF the customer wants that or cares at all. My neighbor could sleep on his deck with train tracks not far away with no problems. Need to drop a bomb beside him to wake him up. Myself I worked shift work and like to use ear plugs or had to. Depends on the individual and how lightly they sleep.

__________________
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote
Old 07-24-2013, 10:24 PM   #47
Experienced HVAC Tech
 
HVAC1000's Avatar
 
Join Date: Dec 2012
Location: Northern Colorado
Posts: 357
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by raylo32
Why is that, Yuri? Bigger coils? My GF has a Trane 16 SEER heat pump and it is enormous.
More coils= more surface area to transfer heat
HVAC1000 is offline   Reply With Quote
Old 07-24-2013, 10:55 PM   #48
Member
 
Join Date: Feb 2011
Location: Southern California
Posts: 71
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by yuri View Post
I disagree somewhat. If it sits on his patio then sound is an issue and worth spending $$ on and if it is outside a bedroom window and can be heard then it is worth spending $$ on a quieter unit IF the customer wants that or cares at all. My neighbor could sleep on his deck with train tracks not far away with no problems. Need to drop a bomb beside him to wake him up. Myself I worked shift work and like to use ear plugs or had to. Depends on the individual and how lightly they sleep.
Can certainly see your point. I am a pretty light sleeper (you never sleep heavy with kids in the house!) but with my AC I tend to notice the air handler more (high rpm direct drive) even with the condenser on the other side of the wall from our bedroom.

Last edited by FixitDragon; 07-24-2013 at 11:00 PM.
FixitDragon is offline   Reply With Quote
Old 07-24-2013, 11:37 PM   #49
DIYer
 
Join Date: Apr 2011
Location: Northern VA
Posts: 175
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Just downloaded the free app and ran some tests uncalibrated...

When I sit in my family room with the HVAC off I hear crickets and the fridge in the kitchen (about 15 ft away)...32 db. My windows are old.
With the AC on, I initially hear the outside unit as it fires up but once the air is moving inside that is louder than the outside unit. I am surprised. 42 db.
The outdoor unit is about 10 feet from my ears. The furnace is downstairs in the basement. I cannot hear it run unless I go downstairs. I can hear the WHOOSH of air when the furnace is on.
I walked over to the air return in the foyer and I got 54 db.
I went outside...crickets are 61 db. If a car drives by, it goes to 64 db (I'm on the back side of the house 150 ft from the road).
AC unit running and me 2 ft away is 77 db. It is old school single speed and always makes the same noise.
I walked to 20 ft away where I'd be sitting on my patio and got 67 db.
mystic_cobra is offline   Reply With Quote
Old 07-25-2013, 05:17 AM   #50
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 1,044
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


I think quieter is almost always better. My unit is like the OP's... single speed, old. It's about 77 dB a couple feet away. But it is 2 floors below my bedroom and sits below a deck so really isn't an issue for sleeping. I will still go for a quieter one for replacement.

Then there is a situation like at my GF's condo. All the condensers are lined up on one outside wall. So even though she replaced hers with a nice quiet unit there are still a couple of the original rattle traps out there that are loud, especially in heat mode. If you want to sleep there you just have to get used to it.

Quote:
Originally Posted by yuri View Post
I disagree somewhat. If it sits on his patio then sound is an issue and worth spending $$ on and if it is outside a bedroom window and can be heard then it is worth spending $$ on a quieter unit IF the customer wants that or cares at all. My neighbor could sleep on his deck with train tracks not far away with no problems. Need to drop a bomb beside him to wake him up. Myself I worked shift work and like to use ear plugs or had to. Depends on the individual and how lightly they sleep.
__________________
Live long and prosper.
raylo32 is offline   Reply With Quote
Old 07-25-2013, 07:59 AM   #51
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,411
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by mystic_cobra View Post
Just downloaded the free app and ran some tests uncalibrated...

When I sit in my family room with the HVAC off I hear crickets and the fridge in the kitchen (about 15 ft away)...32 db. My windows are old.
With the AC on, I initially hear the outside unit as it fires up but once the air is moving inside that is louder than the outside unit. I am surprised. 42 db.
The outdoor unit is about 10 feet from my ears. The furnace is downstairs in the basement. I cannot hear it run unless I go downstairs. I can hear the WHOOSH of air when the furnace is on.
I walked over to the air return in the foyer and I got 54 db.
I went outside...crickets are 61 db. If a car drives by, it goes to 64 db (I'm on the back side of the house 150 ft from the road).
AC unit running and me 2 ft away is 77 db. It is old school single speed and always makes the same noise.
I walked to 20 ft away where I'd be sitting on my patio and got 67 db.
sounds like (no pun) your test is accurate. some of the entry level new units are 76 db and some of the older units of your era were heavy built so it is not so bad in comparison. all I can say is that I can stand beside a 70 db unit and talk to someone w/o raising my voice. not so with a 76 db unit, have to talk fairly loud. now you have 2 reference points to use 77 and 70 to see if spending extra $$ is worthwhile.

although in your first post you said it bothered you inside the house while watching tv and while having guests on the patio, there are quieter than 70 db units, just depends how much you are willing to pay for that lack of sound.

your choice of course, at least you have some science to work with now or the app is not very accurate.
__________________
"Cut it twice and it is still too short".

Last edited by yuri; 07-25-2013 at 08:10 AM.
yuri is online now   Reply With Quote
Old 07-25-2013, 09:15 AM   #52
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,411
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by raylo32 View Post
I think quieter is almost always better. My unit is like the OP's... single speed, old. It's about 77 dB a couple feet away. But it is 2 floors below my bedroom and sits below a deck so really isn't an issue for sleeping. I will still go for a quieter one for replacement.

Then there is a situation like at my GF's condo. All the condensers are lined up on one outside wall. So even though she replaced hers with a nice quiet unit there are still a couple of the original rattle traps out there that are loud, especially in heat mode. If you want to sleep there you just have to get used to it.

louder in Winter why??

because air is denser when it is colder out and sound travels further.

especially in the Great White North. I can hear your dog barking in mid December
__________________
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote
Old 07-25-2013, 09:52 AM   #53
Member
 
raylo32's Avatar
 
Join Date: Nov 2006
Location: Maryland (DC 'burbs)
Posts: 1,044
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


I don't know why... maybe the reversing valves? Or maybe the cold affects the case and access panel clearances enough to induce rattles? I dunno but a couple of these really make a racket. Maybe the cold air/sound transfer, too, although in this case we are talking just 10-30 feet away.

Quote:
Originally Posted by yuri View Post
louder in Winter why??

because air is denser when it is colder out and sound travels further.

especially in the Great White North. I can hear your dog barking in mid December
__________________
Live long and prosper.
raylo32 is offline   Reply With Quote
Old 07-25-2013, 11:16 AM   #54
Experienced HVAC Tech
 
HVAC1000's Avatar
 
Join Date: Dec 2012
Location: Northern Colorado
Posts: 357
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by raylo32
I don't know why... maybe the reversing valves? Or maybe the cold affects the case and access panel clearances enough to induce rattles? I dunno but a couple of these really make a racket. Maybe the cold air/sound transfer, too, although in this case we are talking just 10-30 feet away.
We don't have many heat pumps here so someone tell me if I am wrong, but what I learned in school is that they are much louder when they go into defrost mode. I'm not really sure though so ya.
HVAC1000 is offline   Reply With Quote
Old 07-27-2013, 11:29 PM   #55
DIYer
 
Join Date: Apr 2011
Location: Northern VA
Posts: 175
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


Had another guy come out today and survey to give me a quote. We discussed the differences between the 80% furnace and the newer condensing furnaces. He was nice enough to explain the details so I understood and what would have to be done to upgrade. I also read a bunch online about the differences. I was a little worried about using PVC for a furnace exhaust initially but after reading the details it makes much more sense. I had no idea the exhaust was so cool.
The location of the vent is now a major consideration regarding the distance to the windows, soffits, etc. So much to consider...
mystic_cobra is offline   Reply With Quote
Old 10-02-2013, 10:23 AM   #56
DIYer
 
Join Date: Apr 2011
Location: Northern VA
Posts: 175
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


I am back at this now that fall is here. I'm evaluating my options and I am looking for some clarification...
My current system uses 3" round metal pipe from the furnace and the HWH and they merge at a Y and then go through the wall into the chimney. I'm assuming that the metal pipes don't go all the way up. From the top, you can see the two red square "pottery pipes" like this: http://www.bandbrenovationsandchimne...ney%20Caps.jpg

Is it correct that if I go with an 80% furnace I will need a metal chimney liner (or two)?
And that if I go with a 95% furnace, I won't need a liner but will have to run the set of PVC pipes outside? Does the HWH still need a liner if I go with a 95% furnace?

I'm trying to figure out the difference in cost for the ancilliaries associated with each choice.

Last edited by mystic_cobra; 10-02-2013 at 12:13 PM.
mystic_cobra is offline   Reply With Quote
Old 10-02-2013, 12:40 PM   #57
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,411
Rewards Points: 0
Default

Is NOW a good time to replace my 1986 AC?


we call that a clay tile liner. where I am the gas code states that you HAVE to have a liner and you got away with it due to the grandfather/ as is clause. once you update any wiring or gas appliances then you must update to the new code. you will need a liner for the water heater unless your code does not require it. you will need a smaller B vent insulated liner as there is not enough heat coming out of a water heater to warm up the chimney and it could condense and freeze it up. where I am all new homes have a high eff furnace, no chimney and use a elec water heater or thru the wall type. you lose LOTS of air/heat/$$ up chimneys so getting rid of it is a good idea to save NRG/$$.

any reputable contractor should know the gas code and tell U what U need.

__________________
"Cut it twice and it is still too short".

Last edited by yuri; 10-02-2013 at 12:48 PM.
yuri is online now   Reply With Quote
The Following User Says Thank You to yuri For This Useful Post:
Mikhail (11-06-2013)
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
toilet backing up, random bubbling in sink. this can't be good. wkd Plumbing 2 05-17-2013 10:25 PM
re: replace asphalt driveway. best method?? gramps416 Building & Construction 12 05-24-2011 11:50 AM
Replace or sister floor joists WillK Building & Construction 6 03-09-2011 08:55 PM
Time to replace roof? ken123 Roofing/Siding 6 03-25-2010 12:33 PM
replace galvanized pipe below kitchen sink? Jeremy Hillary Boob, PhD Plumbing 3 04-03-2009 08:39 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.