Zoning Forced Air for Houses

[wundumguy]

Are forced air systems for residential, like a 2,000 sqft house, ever zoned? In Vancouver, it's always one thermostat - one zone. It's nothing like the hydronic systems.

Is it just around here, or is it pretty much standard practice in North America to not zone forced air heating in a house?

[pstu]

I am in TX and most of the 2-story houses have 2 separate systems. That is a simple form of zoning. I believe the more complex form of zoning is regarded as rather exotic and rarely used where I live. I'm a homeowner but don't think that disqualifies me from answering the question.

Regards -- Pstu

[ckr74]

I might be wrong but most 2 story homes = one zone around here anyway. Lots cheaper that way. I zoned my home and it works perfect. Didn't trust anyone else to do it because it's not the standard the to do around here. Not cheap to do either.

[beenthere]

If people are willing ot pay the price to zone a house. Then its done.
If not, then it isn't.

[im4snow2000]

If people are willing ot pay the price to zone a house. Then its done.
If not, then it isn't.

Lets assume a 2 story home on basement in a heating dominate climate. Forced air heat and A/C. Assume total house load is 4 tons cooling.

If you put the furnace/coil/and trunks in basement, and wish to zone the first and second floor seperately, how do you get around the issue of basically being way oversized (4 ton) when only one zone calls for cooling, for example?

One of my collegues suggests to definately have variable spd furnace, and size the zone dampers such that there's some bypass (say 10%). Also, in an ideal world I guess you'd have a two stage compressor.

But in reality, by the time you add up the var spd furnace, 2 stage compressor, AND zoning....the price starts to get quite crazy.

Opinions welcome on this subject.

[beenthere]

I don't let air bypass the zone dampers. Tends to over shoot temp in the opposite zone.

A bypass damper is used. Or a dump zone(won't get into the pros/cons of bypass or dump zone in this thread).

Next. there is at least one manufacturer that makes a modulating after market zoning system. That will open other zones up to prevent short cycling. And keep static pressure down.

Honeywell has the Envirozone system. Its communicating. So the stats constantly talk to the panel. And when the master zone is calling. It determines what other zones to open up and allow conditioning. So that they don't have to call for conditioning themselves 5 minutes later(still requires a bypass or dump zone).

These can be used on regular single furnaces and air conditioners.


Snow. There are several threads about zoning in the pro tech forums. Do a search.

[Wheelbaron]

We zone all the time around here. 2500 to 4000 foot home single story with finished basement with 3, 4 ,and 5 zones is not uncommon here.

[clokwork76]

i am in CT and i do a considerable amount of zoning with much success. is anyone farmiliar with EWC equipment? i use one of their panels that incorporates a supply air sensor with high and low limits... of course proper duct design is the most important factor.

[edbrown]

Check out Arzel - I think its Arzelzoning.com

Great systems - all pneumatic with modulating bypass dampers and lots of parameters that you can set - to get the performance that you need/want.

very easy to install in existing systems too!

[dfelt]

One thing to consider w/zoning is placement of bypass damper whether it,s modulating via feedback info.or barometric type is to attempt to get as much mix w/bldg return air as possible otherwise delta T is affected.Usually more w/heat mode rather than cooling.Have seen a couple jobs where high limit tripping has occured.

[wahoo]

We do a lot of zoning in new construction with good success. Presently installing two GSHP units with zoning. Need to pay attention to duct sizing, but overall work well with very little "over-run". Have done a couple of Arzel systems, however their costs ends up fairly high, but can't beat them for retrofitting an existing house!!

[ga-hvac-tech]

Do some zoning also. It is expensive, and has its own issues... however it also solves some other issues nicely.

Not all HVAC guys understand zoning, be careful who you hire...

[wahoo]

Totally agree, never hire the inexperienced HVAC person to design and install your zoned system! Sadly, we've had other competitors tell our customers the zone system they've had working fine for years in their home would never work. And most will then admit they really don't know anything about zoning because they just put numerous systems in all their homes rather than learn. Sadly, ignorance is no excuse however if you don't know then keep your ignorant "opinions" to yourself rather than open mouth and remove all doubt. Just keep on putting in multiple systems and leave the truly happy folks to contactors like us!! A while back we put a seven zone system in for a banker who wanted to "zone" each bedroom in his house along with the main living area, kitchen and basement. Works great, but it did take a little "figuring" first (along with bypass damper and additional controls).:couch: