View in: Desktop
Copyright @2024 TigerDroppings.com. All rights reserved.
- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Posted by
Message
HVAC Help!
Posted by Neauxla on 10/30/19 at 9:06 pm00
I've gotten 3 quotes so far and all the systems are different.
Quote 1: two 4ton 20 seer single stage units
Quote 2: two 3ton 16.5 see two stage units
Quote 3: 1 5 ton 2 zone system
It's a 2 story house and I'm leaning towards 2 units over 1, but I don't know which setup would be better.
both system are American Standard. Prices are within 1k of each other. Thoughts?
Update:
1st floor: 1309 sq ft
2nd floor: 1147 sq ft
Forgot I will be adding a 200 sq ft (give or take) climate controlled storage room in the attic. (2 of them if I can make it work w/ the furnace and controllers)
Quote 1: two 4ton 20 seer single stage units
Quote 2: two 3ton 16.5 see two stage units
Quote 3: 1 5 ton 2 zone system
It's a 2 story house and I'm leaning towards 2 units over 1, but I don't know which setup would be better.
both system are American Standard. Prices are within 1k of each other. Thoughts?
Update:
1st floor: 1309 sq ft
2nd floor: 1147 sq ft
Forgot I will be adding a 200 sq ft (give or take) climate controlled storage room in the attic. (2 of them if I can make it work w/ the furnace and controllers)
This post was edited on 11/1 at 9:52 am
Are all the bedrooms on the 2nd floor? If so, I would opt for 2 units 16.5 SEER to do the job. That way you could program the downstairs unit to run more efficiently while keeping the bedrooms upstairs cool at night, and vice versa during the day when the downstairs is mostly being used.
I had a 2 story house with a single unit years ago and it just didn't do the job well in the upper floor.
I had a 2 story house with a single unit years ago and it just didn't do the job well in the upper floor.
re: HVAC Help!Posted by LSUgEEkish on 10/30/19 at 10:42 pm to Neauxla
Don't do the 2 zone system ... no one seems to know how to make them work. In BTR at least
You really need a Manual J cooling/heat load determined for your home to determine proper sizing of your HVAC unit (s). Here’s a bit of info to get you started as to why this is important LINK Based on the quotes you’ve obtained it appears none on the HVAC contractors conducted a manual J.
Based on the info you provided 2,400 sq ft, foam insulation in attic, standard fiberglass insulation in walls, new windows ... it appears to me that all 3 companies have likely quoted significantly over-sized systems for your home, particularly quote 1 - 8 tons total for 2,400 sq ft, or 300 sq ft per ton - that’s crazy. The 2, 3 ton units, at 400 sq ft per ton is probably significantly oversized.
My single story 2,400 sq ft home built in 93 is easily cooled and heated by a one single-stage 4-ton system, and a manual J calculation indicates I should have a 3.5 ton system. But that’s the purpose of the Manual J. Consider registering on this site HVAC Talk LINK and pose this same question to have your question answered by HVAC professionals.
I’d suggest you go with 2 units, one for each floor, and you’ll need a manual J conducted for each floor to properly size the unit for each floor. Good to have 2 units, when one invariably goes down, on the hottest day of the year and on a weekend, you’ll have a cool floor you can retreat to until repairs are made.
Also I’ve never heard of a single stage HVAC system with a SEER as high as 20 - you sure you have that right?
Based on the info you provided 2,400 sq ft, foam insulation in attic, standard fiberglass insulation in walls, new windows ... it appears to me that all 3 companies have likely quoted significantly over-sized systems for your home, particularly quote 1 - 8 tons total for 2,400 sq ft, or 300 sq ft per ton - that’s crazy. The 2, 3 ton units, at 400 sq ft per ton is probably significantly oversized.
My single story 2,400 sq ft home built in 93 is easily cooled and heated by a one single-stage 4-ton system, and a manual J calculation indicates I should have a 3.5 ton system. But that’s the purpose of the Manual J. Consider registering on this site HVAC Talk LINK and pose this same question to have your question answered by HVAC professionals.
I’d suggest you go with 2 units, one for each floor, and you’ll need a manual J conducted for each floor to properly size the unit for each floor. Good to have 2 units, when one invariably goes down, on the hottest day of the year and on a weekend, you’ll have a cool floor you can retreat to until repairs are made.
Also I’ve never heard of a single stage HVAC system with a SEER as high as 20 - you sure you have that right?
re: HVAC Help!Posted by East Coast Band on 10/30/19 at 11:17 pm to Neauxla
quote:
Quote 1: two 4ton 20 seer single stage units
So, 8 tons total for a 2400 sf house? Seems WAY too much.
Maybe you meant to say 2 units/ total of 4 tons.
The old general rule of thumb was 1 ton/ 600 sf. Things have altered this some, in both directions. On one side, insulation and the SEER ratings, etc. have gotten better. On the other side, homes typically have higher ceilings now, more/larger windows, more open spaces (no hallways, or at least they need to be kept cool, just like the bedrooms)
This post was edited on 10/30 at 11:21 pm
re: HVAC Help!Posted by CrawDude on 10/30/19 at 11:19 pm to LSUgEEkish
quote:
Don't do the 2 zone system ... no one seems to know how to make them work. In BTR at least
On professional HVAC forums I’ve followed over the past year most HVAC techs say the same thing, very difficult to find HVAC professionals that can can do a zoned system correctly, and they’ll almost alway recommend 2 units, over a single zoned unit, for a two-story home.
TD SponsorTD Fan
USA
Member since 2001
USA
Member since 2001
Thank you for supporting our sponsors Posted by Site Sponsor to Everyone
Advertisement
re: HVAC Help!Posted by notsince98 on 10/31/19 at 8:13 am to Neauxla
My first suggestion is do not purchase oversized equipment. If you need 3 tons for each system and you buy 4 tons for each, you will waste money and electricity and you will have worse humidity control.
2 systems is a nice luxury to have but it seems odd to me to see them both the same size. Usually the downstairs system can be smaller for AC. I would be looking at quote 1 and 2 but get them to properly size units. You might be able to get quote 1 down to a 3 ton for upstairs and 2 ton for downstairs. You'd get 20 SEER, better humidity control and save $$$.
2 systems is a nice luxury to have but it seems odd to me to see them both the same size. Usually the downstairs system can be smaller for AC. I would be looking at quote 1 and 2 but get them to properly size units. You might be able to get quote 1 down to a 3 ton for upstairs and 2 ton for downstairs. You'd get 20 SEER, better humidity control and save $$$.
re: HVAC Help!Posted by notsince98 on 10/31/19 at 8:14 am to gumbo2176
quote:
I had a 2 story house with a single unit years ago and it just didn't do the job well in the upper floor.
Zoning works very well for 2-story homes and is more affordable. It provides all the comfort and efficiency of a 2 system setup.
2 systems is nice just so that you still have a comfortable place somewhere inside if an AC goes down in the summer.
re: HVAC Help!Posted by notsince98 on 10/31/19 at 8:18 am to CrawDude
quote:
On professional HVAC forums I’ve followed over the past year most HVAC techs say the same thing, very difficult to find HVAC professionals that can can do a zoned system correctly, and they’ll almost alway recommend 2 units, over a single zoned unit, for a two-story home.
Zoning equipment is super simple in and of itself. The issue is the ductwork. Not many places know how to properly size the ductwork for zoning systems or how to properly reduce the static pressure the system sees with undersized ductwork. Zoning essentially has to be the focus when the house and ductwork are first built. Retrofitting on a 2 story would be risky.
re: HVAC Help!Posted by Neauxla on 10/31/19 at 12:04 pm to notsince98
Option 1 in detail:
1 AUD1C080A9H41 80,000 BTU 4 TON American Standard 80% EMC Motor High Efficiency Blower 20 Years Heating Chambers 5 Years Parts
1 4TXCC007DS 4 Ton HI-EFF Aluminum Multi Position A Coil 20 Seer
1 4A7A6048 4 Ton 16 SEER R410A Condenser Unit
1 Tstattot Thermostat
1 HCC20-28 Merv 10 Air Quality
Option 2 in detail:
2 16.5 Seer #4A7A7036A
Variable Speed furnace # AUD2B060ACV3
Coil Model 4TXCB004DS
1 AUD1C080A9H41 80,000 BTU 4 TON American Standard 80% EMC Motor High Efficiency Blower 20 Years Heating Chambers 5 Years Parts
1 4TXCC007DS 4 Ton HI-EFF Aluminum Multi Position A Coil 20 Seer
1 4A7A6048 4 Ton 16 SEER R410A Condenser Unit
1 Tstattot Thermostat
1 HCC20-28 Merv 10 Air Quality
Option 2 in detail:
2 16.5 Seer #4A7A7036A
Variable Speed furnace # AUD2B060ACV3
Coil Model 4TXCB004DS
re: HVAC Help!Posted by notsince98 on 10/31/19 at 1:40 pm to Neauxla
Does your house have significantly more square footage on the first floor than the 2nd floor?
Same sized systems would be an odd setup. Both quotes seem oversized.
Same sized systems would be an odd setup. Both quotes seem oversized.
I’d seriously consider quote 2 with the 2-stage systems, particularly considering the price differential compared to the single-stage units. However, unless there is something extremely unusual regarding your house the the tonnage is very likely over-sized. Be aware that two-stage HVACs usually come in “whole” ton sizes (2, 3, 4, 5) whereas single stage units can be obtained in 1/2 ton sizes (2, 2.5, 3, 3.5. ...5).
HVAC techs on the forums I read say the most common problem they deal with in trying to resolve issues of homeowners with HVAC comfort issues is over-sized tonnage and under-sized duct work.
HVAC techs on the forums I read say the most common problem they deal with in trying to resolve issues of homeowners with HVAC comfort issues is over-sized tonnage and under-sized duct work.
Some decent advice given here so far. I'd echo that the first quote is ridiculous. I'd go so far as not only losing their number but also telling friends to lose their number. 8 tons for a ~2500sqft is a setup for disaster. Maybe if you had no insulation anywhere and a wall made of windows facing West then it would be plausible.
3rd quote isn't great as unless they are going to re-do the ductwork. Zoning works well but really needs to be designed when duct is installed. Maybe your house is the exception though.
2nd quote is the most favorable. But I'd ask them about why they feel you need two three ton instead of a 2 and a 3 or even 2 2s.
Assuming you're in the south then high humidity (latent load) is going to be an even bigger issue than actual temperature (sensible heat).
All the money to be made in residential HVAC is unfortunately in selling units. Just the way the industry has gone. A company would go out of business only doing repairs and preventative maintenance. This is to say be careful of the pushy salesman.
3rd quote isn't great as unless they are going to re-do the ductwork. Zoning works well but really needs to be designed when duct is installed. Maybe your house is the exception though.
2nd quote is the most favorable. But I'd ask them about why they feel you need two three ton instead of a 2 and a 3 or even 2 2s.
Assuming you're in the south then high humidity (latent load) is going to be an even bigger issue than actual temperature (sensible heat).
All the money to be made in residential HVAC is unfortunately in selling units. Just the way the industry has gone. A company would go out of business only doing repairs and preventative maintenance. This is to say be careful of the pushy salesman.
re: HVAC Help!Posted by Neauxla on 11/1/19 at 9:46 am to notsince98
quote:Significantly? No. Probably about 200 square feet. Not sure on the exact unless I dig around to find my floor plan/appraisal
Does your house have significantly more square footage on the first floor than the 2nd floor?
Update:
1st floor: 1309 sq ft
2nd floor: 1147 sq ft
This post was edited on 11/1 at 9:52 am
quote:
Update: 1st floor: 1309 sq ft 2nd floor: 1147 sq ft
I’d be willing to bet two, 2-ton, 2-stage units is likely what you require based on your square footage per floor, and the insulation you have in your home based on your previous post. How about your crawl space - is your bottom floor under the house insulated? I assume you’ll have new duct work? Ducts must match the tonnage for optimal performance.
By the way, what size system(s) do you currently have on your home?
Here a free DYI manual J calculator you can use to get you close as to what size HVAC tonnage you need for your home. LINK. I used it to estimate my tonnage need on my 2,465 sq ft conditioned house - manual J said I needed a 3.5 ton unit, I have a 4-ton which works fine but I do think I get some short-cycling b/c it’s slightly over-sized. Got 1 estimate last summer on a replacement unit - HVAC sales person wanted to sell me a 5-ton unit. He was using the old 1 ton per 500 sq ft rule of thumb, not a manual J which considers insulation, leakage, energy efficient windows, house orientation. etc.
quote:Not at the moment. Will do that down the road after my kitchen renovation etc.
How about your crawl space - is your bottom floor under the house insulated?
quote:5 ton single unit which performs like crap.
By the way, what size system(s) do you currently have on your home?
quote:
Here a free DYI manual J calculator you can use to get you close as to what size HVAC tonnage you need for your home. LINK
Back to top
Follow TigerDroppings for LSU Football News