HVAC Zoning

[drozwood90]

Anyone use / heard of this company?

http://www.arzelzoning.com/

It seems like a great idea, and I'll e-bay my electric registers if I can get this system.

--Dan

 

[mustangcoupe]

Dan,

The problem with zoning now is that without proper design you could be hurting the operation of the system by adding zoning or dampers. I beleive there are numeruous threads around this board about adding dampers/zoning to forced hot air systems....

Now I am on Forced hot water and have multiple zones and I feel comfortable adding and changing the zones... (which I will be doing within a few years)

 

[Kevin L]

Todd's right. Having a properly zoned hot-air system is more than adding some dampers. You need ways to alleviate the backpressure, like bypasses. I have zoning in my home, Honeywell's Enviracom, but the system was designed with this in mind from the start.

Kevin

 

[drozwood90]

Todd's right. Having a properly zoned hot-air system is more than adding some dampers. You need ways to alleviate the backpressure, like bypasses. I have zoning in my home, Honeywell's Enviracom, but the system was designed with this in mind from the start.

Kevin

I agree, which is why I was looking at this "system"

It takes this into account. It is a secondary system that you hook temperature sensors into (the normal kind you get at Lowes...or in my case, the one I built). They "trip" as they normally would, which would turn on the furnace or AC.

This system then interprets these requests based on the rules (Heat / Cooling / Auto priority) you have setup.

Then, this system tells the furnace what to do, while configuring the dampers.

It also has a Bypass relief valve you hook into the system to feed the already heated "excess" air back into the return, which allows the gas to burn less (this is why they told me about this, as I was going to use electro-mechanical registers...but then needed to know how many I could close at once. Then the HVAC guys told me about the need for a Bypass Valve so I don't overload the furnace).

But you are both right, it is not just about adding dampers...it's a system that it needed.

I had asked my HVAC guys about automating my system...or adding zones (they came in for a 90 day inspection of my current system in my new house), they pointed me to this product.

Just wanted to know if anyone else used anything like this.

--Dan

 

[Kevin L]

Hi, Dan.

I'm glad you got good advice about the bypass. I looked at the link you supplied and it is similar to another system I looked at. Here's the link.

My HVAC contractor had experience with the Honeywell system, so that's why I went with it. I have a heat pump system, and I've been in the house for 11 months. I am extremely pleased with the system and it works as advertised.

Good luck.

Kevin

 

[aehusted]

adding zoning of some sort has been on my to-do list for a while, especially now that the basement is finished.
It would be great if you could share any pricing info you get from them. I did not see any pricing info on their site.

 

[Herdfan]

I have the arzel zoning system that you mention. It is awesome, but it was put in a system designed to be zoned. Plus, it took a while to get the pressures stabilized. Initially we had freezing problems because the cold return air was too cold due to the bypass being too close to the A-frame. So we moved it back and that fixed the freezing problem. Initally we had the mechanical bypass damper, but it did not seem to adjust well as zones opened and closed, so we went with the static air bypass damper and once the system got dial in, it has been rock solid.

One nice thing about the Arzel is that it uses regular stats. I have Crestron stats hooked to it, but any regular stat like the HAI or Aprilaire should work just fine.

 

[drozwood90]

If you don't mind sharing (as I'm waiting to hear on pricing), how many zones do you have, and how much was it?

--Dan

 

[keepersg]

Dan,

The problem with zoning now is that without proper design you could be hurting the operation of the system by adding zoning or dampers. I beleive there are numeruous threads around this board about adding dampers/zoning to forced hot air systems....

Now I am on Forced hot water and have multiple zones and I feel comfortable adding and changing the zones... (which I will be doing within a few years)

Todd, I have a forced hot water heating system. I'd be very interested in how you zoned yours.

George

 

[Herdfan]

If you don't mind sharing (as I'm waiting to hear on pricing), how many zones do you have, and how much was it?

--Dan

Don't know the exact price breakdown as it was part of a total system install. However, I did get a quote for a 2 zone system for the basement unit to be retrofitted and the quote was $2500, but included some duct work.

 

[mustangcoupe]

Todd, I have a forced hot water heating system. I'd be very interested in how you zoned yours.

George

not to steal this thread but it is zoned into 3 zones right now upstairs, basement, and hot water maker (40 gallon indirect super store tank) Each zone has it's own zone pump I know there are ways to do it with butterfly zone valves and one pump but I was not as confidant setting one of those up...

In the future I was thinkin of seperating the main living area from the bedrooms, but Im not sure if this would be worth it...

 

[pete]

Anyone use / heard of this company?

http://www.arzelzoning.com/

It seems like a great idea, and I'll e-bay my electric registers if I can get this system.

--Dan

a couple of quick pointers..

you should never (like is says in the arzel brochure) run just one zone (unless it's +60% of total air flow)

even with a by-pass if you direct return more than 40% of the air you risk overheating the unit (or feezing the A/C coil)

you mentioned that the system can modulate the furnace "which allows the gas to burn less"..I'd double check that claim..(but if true, you can disregard the previous item as this would prevent any overheating)

if you have more than one register per zone, and they are ducted seperately off the main, you'll need multiple dampers for that zone..

(quoted %'s aren't exact..but you get the idea)

Todd, I have a forced hot water heating system. I'd be very interested in how you zoned yours.

George

guessing your talking hw baseboard, basically you'll need to add seperate suppy and return piping, a zone valve, and a t-stat for each zone you want to create..the first zone can use the existing piping for supply, then you would cut the existing and pipe it to the return, run a new supply, taken off the existing before any new zone valves to the start of the next zone..do the same for any inbetween zones..then the last zone can use existing pipe for return..depending on your existing layout and your desired zones this could be easy or a PITA..and, unfortunately, copper is very expensive lately..

Pete C

 

[Herdfan]

a couple of quick pointers..

you should never (like is says in the arzel brochure) run just one zone (unless it's +60% of total air flow)

even with a by-pass if you direct return more than 40% of the air you risk overheating the unit (or feezing the A/C coil).

As the final solution, we crafted a bypass that can do one of 2 things depending on how a manual damper is set. It can send the bypassed air 1) back into the return air duct. This is the summer solution as it hellps keep the air as cool as possible as my house has quite a heat load on it from 3pm on, or 2) it does into a dump zone in the garage. This allows extra bypass air to go into the garage and help keep it warmer. (Yes I know you are not really supposed to have vents in the garage).

 

[pete]

a couple of quick pointers..

you should never (like is says in the arzel brochure) run just one zone (unless it's +60% of total air flow)

even with a by-pass if you direct return more than 40% of the air you risk overheating the unit (or feezing the A/C coil).

As the final solution, we crafted a bypass that can do one of 2 things depending on how a manual damper is set. It can send the bypassed air 1) back into the return air duct. This is the summer solution as it hellps keep the air as cool as possible as my house has quite a heat load on it from 3pm on, or 2) it does into a dump zone in the garage. This allows extra bypass air to go into the garage and help keep it warmer. (Yes I know you are not really supposed to have vents in the garage).

my garage is insulated the same as the rest of the house, it's heated, on it's own zone (no A/C though)..parking a snow and salt covered car in a garage that will keep it in a slush state (ie:not evaporate the water in a short time), will only make any corrosion happen faster..

..a dump zone is a viable option..when you have a good place to dump to..the dump zone will provide a 'buffer'..you'll loose less heat from the actively heated areas..a crawl space can be a good spot as well..

..alternatively, as long as there is not a huge difference in loads, instead of closing zones (most dampers are not 100% shut off anyway) that are not calling for heat, you can take it down 60% or so, keeps the heat in the house, but provides the comfort factor (and some energy savings) your looking for..


Pete C

 

[drozwood90]

Pete C,

...::==Assuming the 60% is MIN loading ==::...

That's what I was thinking. If I have 10 zones, and one calls for heat, let it get down 1 deg. before calling for heat for ONLY that one zone. However, if it needs heat and a few other zones need it, then kick the heat on.

Depending on the AIR load that is required in my system, I was going to take the other rooms that are not in "need" and PWM air to them during the period that the room that needed air, well needs it. The PWM would be a rotational thing...

For temperature, I was going to use something like if 1deg. difference, the room is in dire need of heat, so heat gets turned on for that room and the 6 lowest temperature rooms. Then PWM the heat around the house's zones keeping 70% loading (if this value is correct) to heat the lowest temp rooms. If after a few minutes some rooms that are NOT in need to heat and were NOT the lowest in temp. become the lowest, then the system rolls through the rooms to make all the other zones uniform in temperature.

If the temperature of 70% of the load's worth of zones is between -.1 and -.99deg low, then for those rooms turn the heat on and PWM the heat through the rooms until they are all up to temperature.

----------------------

Say 4 rooms need air, 6 do not.

Then the 6 that do not would (depending on loading information that I am waiting on from the Installer) turn on 3 at a time or 4 at a time, rotating through say, every 2 minutes. This gives me at least 70% open (again, all assumed values right now). This is assuming that 4 need heat, and the other 6 are the SAME temperature. If they are not, the PWM is adjusted to give MORE time to the rooms that require more heat to make them all uniform.

So start:
Zones 1-4 need heat, they open
Zones 5-10 do not.

Zones 5,6,7 open, 8,9,10 stay shut

2 Minutes pass (depending on how long I have to heat the zones that need it...for the minute assume 10 minutes to make math easy)

Zones 1-4 stay open
Zone 8 opens, 5 closes
Open:
1-4
6,7,8
Closed:
5,9,10

2 minutes

Zones 1-4 stay open
Zone 9 opens, 6 closes
Open:
1-4
7,8,9
Closed:
5,6,10

If one of the original 4 gets to temperature, it will fall into the PWM group, until it gets to some hysteresis point above the setpoint (.1deg...? .5deg..? My installer told me that the thermostat they gave me can be set for .1, .5, 1 deg hysteresis...so I don't know what I'll use yet...)


ETC...etc...

This way the entire house gets heat, so there is a possibility that some zones will not ever call for heat just because they are getting "free" heat to keep the loading down, while other zones require it.

The same would work with AC, and also allow the system to react "better" to thermal loading from the outside during summer.

It's also possible with some sort of hysteresis, I would be able to use the fan ONLY as an option. To take the hottest rooms and mix their temperature with the coolest rooms (or the opposite in summer with AC), before turning on the heat / AC to see if I can prolong the need to use the entire power hungry system (9A starting surge, 6.2A constant run + gas for the heater).

Did any of this make sense?

--Dan