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 06-05-2012, 07:40 PM   #1
Member
 
Join Date: Aug 2005
Location: Portland, OR
Posts: 31
Share |
Default

Zone Existing System?


We are going to be putting a small addition on the back of our 2 story house. While we have some walls opened up, I would like to fix our HVAC system.

During both the summer and winter, our upstairs is about 5-10 degrees warmer than our downstairs. I thought that zoning the system into two zones would help. But then I read that properly sized ductwork should solve the problem. I can fairly easily access the upstairs ductwork (attic), but the downstairs ductwork is not very accessible (very small crawlspace). But if I increase the duct size to the 2nd floor, wouldn't that put more heat to the 2nd floor in the winter?

Any opinions on the best way to fix this problem?

Thanks!

handyman923 is offline   Reply With Quote
Old 06-05-2012, 08:19 PM   #2
Member
 
Join Date: Jun 2012
Location: I live at heatpumpmechanic@gmail.com
Posts: 65
Default

Zone Existing System?


You are right, if you enlarge the duct to the top floor, it will get more air in the winter also, which will overheat the upstairs. Dampers in the ductwork will direct the majority of the air to the area that needs it. This can be done manually, but the Spring and Fall can be problematic (one day hot, the next cold...). A zoning system will adjust the dampers automatically for you.
I would recommend a system with proportional dampers, as opposed to a system with two-position dampers. Two-position dampers are either open or closed, while proportional dampers can be partially opened. A system that uses two-position dampers will wear out your system faster, because it will turn your equipment on & off much more than the proportional type. I would be happy to explain why if you are interested.
An example of a proportional system is Carrier's Comfortzone II. There are not many proportional systems out there.
While zoning is a great option, it is not as good as having two separate systems (one for the top floor, one for the bottom). The only reason to choose zoning over two sparate systems is the price.

TopTechnician is offline   Reply With Quote
Old 06-05-2012, 08:46 PM   #3
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,778
Default

Zone Existing System?


Zone it. Honeywell has their Envirozone communicating system which works good for 2 story homes. Its an auto mastering system. In the winter your second floor won't be able to start the heating system, it will only get heat when it needs it and the first floor zone is calling for heat. In the summer, the second floor will become the master zone, and the first floor will only get cooling when it needs it and the second floor is calling for cooling. Anytime the master zone is calling for cooling or heating, it looks at the set temp of the other zone, and what the actual temp is. then opens that damper to allow some conditioned air to go to it if it is cooler or warmer by X tenth of a degree.

It is not a proportional zoning system, the dampers are either open or closed, but it eliminates short cycling caused by many other zone systems.
beenthere is online now   Reply With Quote
Old 06-05-2012, 09:48 PM   #4
Member
 
Join Date: Aug 2005
Location: Portland, OR
Posts: 31
Default

Zone Existing System?


Thanks for the replies. Just a few followup questions:

- Since we are adding about 350 sq ft to the upstairs of a 3000 sq ft house, should I bother resizing the upstairs ductwork if I install a zoning system?

- Is the Honeywell Envirazone a DIY install? I have installed plenty of ductwork in th past, but I am not sure how technical this would be.

- Do I need a bypass damper? Does it matter if you install the bypass damper on the lower ductwork or the upper ductwork?

Thanks!
handyman923 is offline   Reply With Quote
Old 06-05-2012, 10:04 PM   #5
Member
 
Join Date: Jun 2012
Location: I live at heatpumpmechanic@gmail.com
Posts: 65
Default

Zone Existing System?


While I am not familiar with the Honeywell zoning product, most zoning system manufacturers recommend slightly oversizing the trunklines to help keep the airflow up when some (or one) zones zones are closed. So, I would say yes, you should increase the size of your ductwork. Do you know for sure that your existing system will handle the additional load?
I can't really comment on whether or not the Envirazone is a good candidate for DIY. Honeywell is not known for its well-written installation instructions (though Carrier isn't either). You should be able to download a copy of the installation instructions and read through them so you could decide for yourself.
I'm sure it will require a bypass damper. It needs to come off of the main trunkline BEFORE the zone dampers, and then connect back into the return duct as far from the furnace as possible. Alternatively, the bypass can discharge into an area (room) where the temperature is unimportant, as long as this area communicates with the conditioned space.
TopTechnician is offline   Reply With Quote
Old 06-06-2012, 04:23 AM   #6
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,778
Default

Zone Existing System?


Quote:
Originally Posted by TopTechnician View Post
While I am not familiar with the Honeywell zoning product, most zoning system manufacturers recommend slightly oversizing the trunklines to help keep the airflow up when some (or one) zones zones are closed. So, I would say yes, you should increase the size of your ductwork. Do you know for sure that your existing system will handle the additional load?
I can't really comment on whether or not the Envirazone is a good candidate for DIY.


Honeywell is not known for its well-written installation instructions
You can say that again.


(though Carrier isn't either). You should be able to download a copy of the installation instructions and read through them so you could decide for yourself.
I'm sure it will require a bypass damper. It needs to come off of the main trunkline BEFORE the zone dampers, and then connect back into the return duct as far from the furnace as possible. Alternatively, the bypass can discharge into an area (room) where the temperature is unimportant, as long as this area communicates with the conditioned space.
The Envirozone can be done DIY, at least one member here has installed one himself.

A bypass will be needed. I prefer to connect it so as to give the air in the return time to mix with it.

The duct for the upstairs should be made 25% larger then the area would call for if it wasn't a zoned system.
beenthere is online now   Reply With Quote
Old 06-06-2012, 09:54 AM   #7
Member
 
Join Date: Aug 2005
Location: Portland, OR
Posts: 31
Default

Zone Existing System?


Do you have any recommendations as for they type of Honeywell dampers to use?

Also, can I put two dampers on the downstairs zone? Two ducts come off of the downstairs plenum.

Thanks!

Last edited by handyman923; 06-06-2012 at 11:04 AM.
handyman923 is offline   Reply With Quote
Old 06-06-2012, 04:30 PM   #8
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,778
Default

Zone Existing System?


Yes, 2 dampers can be daisy chained to work together. Honeywell ZD for rectangular/square dampers.
beenthere is online now   Reply With Quote
Old 01-14-2013, 08:44 PM   #9
Member
 
Join Date: Aug 2005
Location: Portland, OR
Posts: 31
Default

Zone Existing System?


I am getting ready to move forward with my zoning project and I am trying to pick out a control panel. I have a couple of questions regarding the Honeywell Envirazone system if anybody is able to help:

1) With a networked system, how does it prevent short cycling? Does it just prevent the secondary zone from coming on by itself when it only needs a little bit of heat?
2) If I was to manually adjust the themostat on the secondary zone, would the system not come on (at least until the primary zone comes on)?
3) I know this system requires a Honeywell VisionPRO IAQ thermostat. Do they have any compatible thermostats that are WIFI enabled?

Thanks for any advice.

handyman923 is offline   Reply With Quote
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
Boiler System Repair slamseven Plumbing 12 10-10-2011 09:47 PM
Modifying the PVC piping on the existing radon mitigation system bjmarchini Building & Construction 4 10-10-2011 12:57 AM
Adding new zone makapacs HVAC 0 11-26-2009 12:35 PM
need some help sorting out my new heating zone please wombosi Plumbing 3 04-23-2009 04:54 PM
Replace furnace, coil and duct system sps123 HVAC 2 01-07-2006 10:56 AM




Top of Page | View New Posts

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