During the cold days winter it's nice to get cozy by the fireplace or curl up under a warm blanket.. or in the summer you might find yourself standing in front of the air conditioner vents or a fan for a little relief from the heat. Is this because it's just not possible for your entire home to be comfortable? It may be because you are concerned with the energy use or $$ being spent to keep the home cool/warm OR it may be that certain areas of your home just never seem to be comfortable. If one or more rooms in your home seem to ALWAYS be outside your "comfort zone", Ecojay's SmartZone may be able to help. Directing airflow (heat/cool) to the rooms that you want, can make rooms in your home comfortable when you want them to be.
Installing zone control in your home allows you to add thermostats to several areas (rooms) so temperature can be controlled throughout the house. Most homes have only a single thermostat located in a "central" area. This means the temperature of the whole house is determined at this one spot. With zone control, temperature is measured and controlled in each zone for more comfort everywhere.
There are many reasons that zone control might be desirable (or even necessary).
- Homes with two stories where the upstairs is regularly warmer than downstairs during the winter can benefit from zone control.
- If a house has a fireplace that causes some areas of the home to get too cold when a fire is burning, zone control can help balance the temperature and keep those cold areas warm.
- Bonus rooms or unused bedrooms can be turned off with zone control when not in use.
- Computer rooms or grow areas that need to be a different (more consistent) temperature than the rest of the house.
Zone control can balance temperatures to create a comfortable living space throughout your home or create different temperatures throughout a building for varying needs.
CLICK HERE to find out more about how HVAC Zone Control works and if it will work for you.
So you've probably heard of someone refer to an air conditioner's size in terms of "TONS". Something like "I got a new 4 TON HVAC unit". This refers, not to physical size, but to the capacity (ability) of the equipment to generate heat. That's right, even air conditioning (cooling), is sized by it's ability to produce heat. In the case of air conditioning, the heat is being "pulled" from inside the house and dispersed outside. This is why there is always an outdoor component (the air conditioning compressor) when you have AC.
Back to TONs... most people thing of a TON as being 2000 lbs. but with regard to HVAC, a TON is a measurement of heat generation per day.
1 TON of air conditioning is a measure equivalent to the amount of heat necessary to melt 2000 lbs of ice (H20) in a 24 hour period.
But how did we get there? A BTU (British Thermal Unit) is the unit we use express heat energy. One BTU is equivalent to the amount of heat energy released when burning 1 match all the way. When rating an HVAC unit either for heating or cooling, the amount of BTUs per Hour is often sited. It has been measured that it takes 143 BTUs to melt 1 lb of ice. Since, 1 TON of ice is 2000lbs, It will take 2000 x 143 = 286,000 BTUs to melt 1 TON of ice. The ice could be melted by lighting 286,000 matches all at once or by lighting one at a time... In other words, BTUs only tells us how much heat energy is necessary but not over what time period. It could melt in 1 minute, 1 hour, or even 1 year depending on how the energy is generated. So, to rate the output of HVAC equipment, someone decided back in the early 1900s (probably someone at Carrier) that it should be done over a 24 HR peroid (1 day). This is how we get 286,000 BTUs / 24 hrs =~ 11,917 BTUs per hour or commonly know as 12K BTU/hr is equal to 1 TON.
This means that that 4 TON AC unit you have can melt 8,000 lbs of ICE per day or about the same size block of ice as a Suburban. That's a lot of heat energy!
An ADD-A-WIRE device can be used when upgrading to thermostats that need a "COMMON" wire from one that didn't have one... and there is no way to run the additional wire needed. This device, ranging from $15 to $40 can come in very handy especially in the case of zone control where one or more thermostat does not have enough wires to accomodate a modern thermostat such as a WiFi thermostat.
Be sure to follow the wiring diagram for the specific model of "ADD-A-WIRE" as well as the system type. Show here is the LUX Products LPB-WH Power Bridge wired to a GAS/ELECTRIC thermostat and SmartZone-4X controller, however, the basic principal is the same for any application.
All of the different ADD-A-WIRE models come with instructions, read them carefully and follow exactly and you won't have any problems.
For more information about the method of ADD-A-WIRE when there is no way to run an extra wire from your zone panel to your equipment, check out this post:
From an engineering perspective this is an elegant and simple solution. Without giving away trade secrets, the ones i have tested use the a half wave bridge using diodes at the thermostat and some simple relay logic plus the another half wave at the equipment (no micro necessary) to use only 1 wire for both Y and G signals.... brilliant.
For more information, or with any questions, please contact us.
So, maybe you have decided to upgrade to a Wifi thermostat, or even just a standard "programmable" thermostat... only, you come to discover that your old thermostat has one less wire connected to it than the new thermostat needs. This is usually the "24VAC Common" wire sometimes just called "C" or "24C". This means that your old thermostat was either mechanical, power stealing, or battery operated... which isn't a problem if you don't want a modern thermostat. MOST modern thermostats (especially WiFi) need a "C" wire from the 24V transformer to power the thermostat... this means getting a "C" wire to the thermostat.
This isn't a new problem, it started showing up in the 1980s with the first programmable thermostats... over the years, I have suggested and used several different methods to overcome this issue both with zoning and with typical single thermostat applications. Until recently, I couldn't really recommend anything other than running a new wire... and running a new wire isn't always possible.
METHODS to add "C" Wire
- Run another wire to the thermostat
The most straightforward and full-proof method is obvious: run another wire. If possible, this is ALWAYS your best solution.
- Power thermostat from separate transformer
Don't use this method... it is risky and not all thermostats support the ability to separate the "R" from the equipment transformer.
- Use the "G" wire for "C"
This method DOES work but it limits the functionality of your thermostat control. (ie. you will not be able to independently control fan from the thermostat) The reason this works, is that the equipment automatically turns the fan on during a heating or cooling call, so the "G" wire controlling the fan from the thermostat is only necessary to turn the fan on by itself. You will NOT be able to turn fan on from the thermostat by itself with this method.
NOTE: This works with MOST equipment, but you should check or test before employing this method. (#3)
- ADD-A-WIRE Device
It is the BEST method and really the only method I would use if a wire cannot be run. This is a relatively new concept to me... it has been around for a few years at least but we just started recommending it within the last 2 years. Several companies have started offering an "ADD-A-WIRE" device that allows the addition of a "COMMON" wire. These devices range from $15 - $40 and are very simple to wire (you have to be able to get to your equipment furnace/blower).
How an ADD-A-WIRE Device works:
It will come in 2 pieces, one is a small box with several connections labled "R", "C", "Y", "G", "W". You will follow the included wiring instructions to connect this box at your indoor HVAC equipment. The other piece that comes with the ADD-A-WIRE is a wiring connector with 3 leads, this connects at the back of your thermostat as shown in the wiring instructions.
Once these two pieces are wired properly you will have the "C" you need for any thermostat... it's almost like magic (electrical engineering magic).
NOTE: Make sure all wiring is done with the power to the HVAC equipment OFF at the breaker.
A few different models to choose from (prices on amazon at time of writing) There are many others available but they all do the same thing (NOTE: we are not compensated by any of these companies or any others for our opinions):
For more information about specific use with zoning and zone control systems such as SmartZone... contact us
Another thing to consider: The ecobee3 and ecobee3 LITE both come with an "ADD-A-WIRE" type device. So, if you are thinking about a WiFi thermostat and are afraid you will need to add a wire... keep the ecobee in mind. See our WiFi stat roundup for more info
We have discussed here the myths and facts about zone control and bypass. As the debate still continues, ecojay SmartZone has yet another innovative way to reduce or possibly eliminate pressure relief (bypass, dump zone, etc) in certain circumstances.
- Variable/Multi speed fan (DS/BK/DH* Terminal on equipment)
*DS/BK/DH energized = High speed fan
- Two (2) Zone systems only (although a 4 zone board can be used)
- One of the zones cannot be smaller than 30% of total airflow
This method will only allow high speed fan when BOTH zones are calling. If only one zone is calling, low speed fan will run. NOTE: The system, depending on duct sizes, may still require some method of pressure relief even if it is much less. Typically, a small amount of "leakage" into the largest zone when the smallest zone is calling will accomplish what (if any) pressure relief is needed. If using ecojay SmartZone dampers, they can be set easily to leak any amount of air necessary.
SPECIAL NOTE: This method is VERY similar to using zone 1 thermostat for controlling DE-humidification. For more about this see the article here.
Always find out more by contacting us at ZoningSupply.com about your application.
Although SmartZone does not have any built-in capabilities for controlling DE-humidification (DH) or Humidification, some applications are possible by using a thermostat on ZONE 1 that does have the capability to control DH.
Before we get to zoning, the equipment being used must have the capability to control humidity. This usually means it has a terminal (DH/BK/DS) that is energized or DE-energized by a thermostat to control fan speed of the equipment. Controlling fan speed allows the equipment to DE-humidify the air when the fan is running in low speed.
Back to zoning, using zone 1 thermostat to control DH is not as simple as wiring directly from the thermostat to the equipment. PLEASE DO NOT DO THIS. The equipment and the zone thermostats are running on different transformers and this will case problems and potentially damage to some components. You could isolate the output from the thermostat with a relay to get around this issue of different transformers but you would still have an issue with this method of wiring "around" the zone controller. The issue can arise when zone 1 calls for DH but the equipment is already running in heat, this mixed signal might just be ignored by the equipment but we cannot take that for granted... all equipment works differently.
The best way to control DH using SmartZone on single stage equipment is by using the method below. It may seem a little UN-orthidoxed but it is a valid APP note from the engineer at Ecojay (It's intended to work this way).
- Select a DH enabled thermostat of your choice
- Connect Y2/ECO on SmartZone Zone 1 to Zone 1 Thermostat DH/DS/BK
- Connect Y2 on SmartZone Equipment toEquipment DH/DS/BK
- Set Zone 1 "STAT TYPE" to G2
- Set DIP switch #4 to "LOCKOUT"
Zone 1 thermostat will now enable and disable DE-humidification any time the equipment is running in the cooling mode.
NOTE: When starting cooling from OFF state, 90 second delay will occur before HIGH speed fan will energize.
Using this method we are assuming that the equipment is expecting DS/BK/DH input terminal to be ENERGIZED for high speed fan and DE-ENERGIZED for low speed fan. This method should not be used for more than 3 zones or with multi-stage compressor equipment.
Typical wording for HVAC Mechanical drawings to include SmartZone Zone control (2 to 8 zones):
Just a few short years ago, WiFi thermostats were only made by a very few companies starting with Ecobee and RadioThermostat, followed by Nest. A couple of years pass and big names in the HVAC industry (Honeywell, Emerson, Venstar, etc) join the WiFi thermostat party. In 2017 we have more to chose from than can easily be kept up with. Note: All prices as of this article publish date.
All of the WiFi thermostats listed below will work with any SmartZone
I am sure there will be even more on the market in 2018, we will keep watching the WiFi thermostat bubble grow! More than 15 are listed here (and I know they are not all listed). If you know of any more, comment or tweet to us @zoning_supply
VALUE CHOICE #1
Lux PRO GEO - $ 115, Geofencing, Mount Vertical or Horizontal, Color: Black or White
Any information in this article should be verified with the manufacturer of each product listed. Specifications, prices & availability are all subject to change and will not be kept current on this post. Please email us if you have any questions.
ALSO NOTE: We (I) have not been paid or compensated in any way for this article by any of the manufacturers of these products. I have not even received any free product... anything reviewed has been purchased through retail outlets and tested with SmartZone zone control products for the use of ZoningSupply.com customers. This information is not intended to be exhaustive or claim expert knowledge about all of these thermostats. Thank you.
Some systems with many small ducts leading to each zone can require lots of dampers. The example below is a 2 zone system that requires 6 dampers per zone (12 total). If you look at the zoning guide, you will find that you should budget for at least 55VA for this system... but you only have 40 VA transformers. 75 and 100 VA transformers can get VERY expensive! Instead you can use two 40VA transformers, but not how you think. It can be dangerous and unreliable to connect transformers in parallel to create ~80VA. We recommend the method below that employs the use of a simple relay to separate half of the dampers to be powered from a second transformer and the other half being powered by the SmartZone and it's transformer.
See the SmartZone Install Guide to calculate required VA.
It is always necessary to verify that the PRIMARY side power is sufficient to power the transformer connected. A dedicated PRIMARY circuit is best but not always possible. If sharing the 110V or 220V circuit, make sure the total power required for all devices connected (including zoning transformers) doesn't exceed the capacity of the circuit (usually 15 or 20 AMPS).
Where to get a relay?
Any 24V relay with a DPST or DPDT configuration will work. The one pictured in the above diagram is available at ZoningSupply.com (see below). If you are chosing your own relay, the "Contact" current rating will determine how many dampers can be connected. (For example: A 10 Amp relay can handle up to 10 power open, power closed dampers)
If you have a small office or commercial building that has multiple rooms & different people using these rooms, you have probably experienced that some rooms or areas can be comfortable while others are not. Temperature can fluctuate throughout a building depending on the time of day, time of year, activity or usage. Sophisticated and complex systems for LARGE commercial buildings use sensors placed throughout and computer-controlled equipment at adjust capacity of cooling or heating when needed. Smaller commercial buildings, however, use basically a "residential" type thermostat control with just larger equipment than you would find on a home. (Side note: Residential HVAC equipment up to 5 ton, "Light" Commercial HVAC equipment can be up to 20 ton as long as it uses standard 24VAC control)
In "light" commercial applications like:
- Shared office spaces
- Doctors offices
- Small to medium office buildings
- Massage / Salon
- Many more!
SmartZone can be added to give control in each different area of the office. Occupants of different offices might simply have different comfort preferences or some rooms might have specific needs for temperature control such as an IT / computer room. Also, rooms that are occasionally used (conference room) can be turned off when not in use to reduce HVAC equipment run time and help keep the rest of the building comfortable.
Having a thermostat for control in each room has obvious advantages in many applications, additionally, SmartZone offers an ECO-mode feature that is especially useful for commercial/business applications. The ECO-mode feature allows the building manager to put the entire system (up to 20 zones) into "setback" either on a schedule with a timer OR with a basic switch. You can even tie the ECO mode to most security systems so that, when it's armed, the SmartZone goes into "setback." ECO mode will prevent thermostats from running the equipment unless ZONE 1 is running. It can be a hassle to make sure that all your thermostats have been turned off at the end of every day, with SmartZone, you can turn them all off in one place.
Universal 4-Zone Controller
BEST ZONE CONTROL AVAILABLE!
Replace almost any brand existing zone control ... use with any thermostats (even WiFi like nest and ecobee).
Control heating and cooling comfort room by room.
- EASY INSTALLATION - no screwdriver or voltmeter required
- UNIVERSAL COMPATIBILITY - drop in replacement for many models (see list in Additional Info)
- BEST FEATURES - built in Fresh Air Control, expansion port up to 20 Zones
- SUPPLY AIR TEMP SENSOR - included for Smart-Staging & equipment protection
- DESIGNED & ASSEMBLED IN THE USA
SmartZone is simple to install and setup & it can be used with virtually any equipment (Gas, Electric, Heat Pump, Fossil Fuel, Dual Fuel, Up to 2 stages cool, 3 stage heat). Many applications call for different types thermostats and SmartZone works with all of them, giving the building owner the flexibility to purchase any thermostat that suits their needs. WiFi thermostats are a popular option and SmartZone is the perfect match for Nest, Ecobee, LuxPro, RadioThermostat, etc. Literally any thermostat you choose!
Tired of flimsy residential-grade rectangular dampers that easily bend and bind and, worse yet, stop working prematurely. We, at ZoningSupply, are too! And, we have the answer with this commercial-grade, super-duty rectangular damper. Like all of our power dampers, it includes the best motor in the industry (Belimo) and now is constructed with heavy guage aluminim for rigidity and long-life.
8" X 8" thru 24" X 24"
New & Improved Heavy-Duty
Aluminum rectangular damper w/ Ecojay by Belimo motor
Built to stand up to use and abuse
SHIPPING TIME: 2 Weeks
(because they are made to order)
RETURNS for rectangular dampers require 35% restocking fee because they are custom made to order... make sure you order the correct size.
NOTE: Order "Height" for the side with the motor.
No other rectangle zone damper on the market is as sturdy or reliable. Simplicity of design and precision manufacturing in the USA (Ohio & Texas) make for the BEST rectangular damper that has ever been available to the residential zone control market. Try it for yourself today.
Many homes these days have such tight seals around doors, windows, and even closed-cell foam insulation... they are almost air-tight. You can think of an old house like an antique metal or wooden ice box where modern homes are more like Yeti coolers. While this is great for keeping temperatures steady inside the home, it also can trap moisture and toxic gases inside. Fresh air ventilation is necessary to keep a healthy and efficient home.
But how much fresh air is needed? If you bring in too much, you will make your HVAC equipment work too hard and loose efficiency. If not enough fresh air is brought into the home, the air can become humid and allow mold growth or VOCs and other toxins can build up. Luckily, the national organization ASHRAE has a specific recommendation for the amount of air based on occupancy and square footage of the home. See table below.
However, this table should not be taken as gospel. Just like other HVAC calculations and estimations, many factors are not really being taken into account with this rough estimate based on # of bedrooms (occupancy) and square footage. Some adjustments may be needed based on factors such as climate, ceiling height, other air-leakage, etc. To comply with 62-2 is the baseline & adjustments can be made in the field by setting run-time.
Learn more about how SmartZone-4X can control fresh air more efficiently than a separate fresh-air controller in the Install Guide
We have explained in other posts on ZoningSupply.com, when it comes to HVAC zoning, each application must be evaluated individually. Situations vary widely from building to building, but, in all cases HVAC Zone Control puts the user (homeowner, building manager, etc) in control of comfort.
Let's rewind, what is zoning? Homes and buildings that have "central" heating and air conditioning typically have 1 thermostat that controls the whole house temperature. With zoning, multiple thermostats can be placed throughout the house to better control temperature throughout. SmartZone connects to all of the thermostats & automatically controls dampers (air valves) installed in the air ducts. These air ducts direct air from the heating & cooling equipment to the different areas or "zones" of the home/building. The dampers allow SmartZone to direct air only where needed.
Once a SmartZone has been installed, you will have the ability to set each of the zone thermostats to whatever temperature or settings you desire. SmartZone will, within reason, keep each zone at the correct temperature by running the equipment and directing hot or cold air into the zones only when necessary. This achieves the purpose of comfort control to manage hot or cold areas of your home.
As for energy savings, if some of the zones are rarely used and can stay off for a sufficient amount of time, the equipment will run for a shorter time to heat or cool the rest of the building. This and other applications that allow the user to turn off or set-back one or more of the zones can, in some cases, result in energy savings. Some sources have published % energy savings possible with zoning, however, this is too arbitrary to have any real meaning. Like stated at the beginning, every application is different & the real possibility of energy savings is in the hands of the user and how the thermostats are set.
Zoning is an amazing solution to comfort issues and gives the user ultimate control over comfort throughout the home or building. However, zone control is NOT a magic bullet for energy savings. HVAC Zoning only puts more control in the hands of the user & it is ultimately the thermostats and how they are set that determines potential energy savings.
The reality is that in a normal home with one thermostat, the only way to get more "comfort" is to spend more energy (ie run the AC or heat). With zoning, you can stay more comfortable in some areas while reducing run-time by not heating/cooling other areas.
SmartZone is the best hvac zone control for upgrades or new-installs. Order today and install yourself of call any HVAC contractor in your area for installation.
There are many reasons that distributors should take a look at stocking SmartZone, but basically because they can make more money & have a higher customer satisfaction with a very low up-front investment.
- Only 2 models needed to cover all applications.
A lot of manufacturers require stocking 5,6... even dozens of different products to get the best price. With SmartZone, you only need the SmartZone-2 and the SmartZone-4X. That's right, only 2 models will cover everything from 2 zones to 20 zones, single & multi-stage, gas/electric & heat pump (including dual fuel). As a bonus, the SmartZone-4X has built-in Fresh-Air control.
- Best wholesale pricing.
Options for small and large volume distributors with 30 day NET terms pending credit approval. Start with a small order or only 10 zone controllers. Contact ECOJAY (www.smartzoning.com) for details.
- Documentation & training.
Ecojay is committed to supporting distributors with documentation, signs, marketing materials, phone & online support. Ecojay will even do an in-person training for contractors at new distributor locations (minimum order required for free training - normal price for training $500)
- Increase zone control profits & sales.
SmartZone has allowed many of our distributors to increase sales of zoning because it is so much easier for contractors to use & install... they buy more. Distributors of SmartZone also have increased margins on the higher-end controllers because SmartZone-4X can do everything the Honeywell HZ432 can do at a much lower price.
- Contractors will love you for it.
Even contractors that "don't do zoning" occasionally come across a system that needs it or a customer that wants it. SmartZone is the best the the occasional zoning contractor or the contractor that does it every day. Most contractors that try it, don't want to use anything else.
Right now, only about 25-35% of the US has physical distribution of ECOJAY products, specifically SmartZone. This is a HUGE missed opportunity. Online distribution reaches nationwide, but even this is in it's infancy. SmartZone deserves to be on the shelf of your local distributor and contractors deserve to have access to it. Right now it is available on Amazon.com, Ebay, ZoningSupply.com for contractors in the US & Canada to have in a couple of days shipping time.
It would be great if some of the large online supply houses like ... Supplyhouse.com or AlpineAir.com would stock SmartZone so it could be purchased and shipped along with systems. Or some of the national-chain distributors like Johnstone would also carry SmartZone for the sake of availability and exposure to SmartZone style zoning.
SmartZone is not a new gimmic in zoning, it is simply the BEST traditional forced-air zone control board that is available. SmartZone has been designed with the HVAC contractor in mind and it shows with the feedback that is received over and over again from contractors. SmartZone has been shipping since 2004 and has had rave reviews from the beginning.
Contractors that never liked zoning before even love SmartZone. Many of the problems that people had 10 or 15 years ago with zoning such as freezing coils or short cycling have been solved by more sophisticated zone controls but SmartZone made it simple. Using Ecojay SmartZone makes zoning simple.
First of all, if you are not familiar with HVAC Zoning (Zone control) for your home you can click here and learn more about how it works.
Sometimes, zoning is pitched as a device that can be added to your current HVAC system that will "save you energy" because you are able to turn "off" heating and cooling to areas that are not being used. Sounds good, right? Well...there a "but." This as actually a highly debated or more aptly put... highly contested claim among HVAC professionals.
The simple fact is that it isn't a simple answer but the simplest version is: HVAC Zoning CAN save energy in some applications.
Not all applications of zoning are intended to save energy, some are set up to optimize comfort. In these situations, energy savings may not the top priority but it can still be set up to help save energy when the comfort is not in demand.
Zoning puts the control in the hands of the user (homeowner) via the thermostats. These thermostats can be set to optimize energy savings or comfort... or, most likely, somewhere in between.
Some believe the primary purpose of zoning is comfort & I would agree, but, SmartZone can be used in some applications to save energy by reducing necessary run-time.
As far as I have found there have been very few and NO independent studies on the energy savings capabilities of hvac zone control but I have personally been in the industry for 14 years and I believe I know why. Every test I have seen is try to prove some % of energy savings and yet there is a flaw with even the question that is being asked. The problem with this question is that it is looking for an automatic percentage saving when zoning is installed. I think this gets to the heart of why the professionals that dispute zone control's ability to "save energy" do so.
This is an IMPORTANT NOTE: HVAC Zone Control by itself will NOT save energy. However, it CAN be used to save energy.
A proper study to prove that zone control CAN save energy would be straight-forward. Two identical houses with identical hvac systems, one with a 2 zone system & the other with a single thermostat. On the house with zoning, set one thermostat to OFF 12 hours per day and the other thermostat to run a normal 24hr / 7 day schedule. The thermostat schedule should be the same as the 24hr / 7 day schedule in the house with only one thermostat. This study would show that zoning can save energy if used in certain ways.
SmartZone has been around since 2004 and we have over 200,000 installed in the field. We have seen direct feedback that empirically shows energy savings, not just in isolated cases but in extremely high volume. First hand, real-world experience shows that it can be done, but it also shows that in cases where comfort is the priority... energy savings isn't a guarantee with zone control.
Check out SmartZone at ZoningSupply.com
There has been a lot of buzz around eliminating bypass more so lately, but it has been talked about for 20+ years. Some states have even mandated that all new Zoning systems be installed without bypass in certain types of buildings. Others have argued against bypass for many years but only recently have HVAC zone control manufacturers offered products specifically designed to eliminate bypass. Although these products are new, the principals they employ are NOT. The different products on the market are just elaborate ways of "leaking" air into zones or areas that are not calling for it.
At ZoningSupply.com we rely on more than 2 decades of HVAC Zoning experience to come up with our recommendations and with regard to eliminating bypass, we do have some suggestions of applications with SmartZone that have worked well.
First of all, how many zones do you have? The more zones you have the more difficulty you will have operating without a bypass. It becomes more challenging because the amount of surplus air and air pressure in your duct work increases when (worst case scenario) your smallest zone is the only zone calling and all other zone dampers are closed. A zone system with more than 4 zones needs bypass almost certainly.
Secondly, how large are your zones ducts? Are they capable of handling the excess CFM of air that will be generated when other zones close? Most duct can handle much more airflow than it is designed for but only up to a point. Make sure that the smallest zone is capable of handling most or all of the airflow when the other zones are closed. If the smallest zone is NOT capable of handling ALL of the airflow then there are at least a couple of options of techniques that can be used to possibly still eliminate bypass.
Airflow management techniques that can be used in conjunction with each other to reduce or eliminate the need for bypass on a zoning system:
- Over-sized ducts - increase the size of ducts and dampers beyond normal spec.
- Leak into zones - adjust the dampers stop screws so the dampers "leak" a fixed amount of air into some or all zones (no more than 25% recommended into each zone).
- Dump zone - a room or rooms where the duct does not have a damper and will receive air flow any time the hvac system is running.
- Managed dump zone - use a "bypass" damper connected to "dump" duct into any or all zones. Adjust the bypass damper to stabilize the static pressure when the smallest zone only is calling. This is much preferable to the other "Dump Zone" because you are not dumping air when it isn't necessary which can affect air speed.
Multi-stage HVAC equipment - If your current hvac system has multi-stage (2 or more speeds) SmartZone can select the appropriate speed based on the number of zones calling (if set to 2nd-Stage Lock). This capability can significantly reduce the amount of surplus air volume and pressure that would normally be bypassed because when only 1 zone is calling, the equipment will be in low speed.
Even with all of these techniques there are some systems and applications that just must have a bypass & for that we recommend the static pressure controlled version. You can find more about why this is best in another blog post on ZoningSupply.com.
When it comes down to it, with Bypass or any other type of pressure relief on a zoning system, there is a balancing act between air velocity/noise. You want to relieve or bypass as little air as possible to maintain efficiency of the HVAC system, however, with zoning it is inevitable that the air velocity will be come too high when only one zone is calling and that is why some combination of the techniques discussed should be used with any zone control system.
We are proud to announce the continuation of our damper product line here at ZoningSupply.com with the "Insert-able" damper.
Some applications call for dampers that can be "slipped" into round duct that is spiral or other hard pipe style duct. This is not intended for use with flex-duct but can be used with any other type of hard duct. Simply cut a slit in the duct, insert the damper and screw it down.
4", 5", 6", 7", 8", 9", 10", 12" ROUND Diameter Dampers
Industry-leading quality & highest reliability, Belimo Motor, Full-seal gasket blade, makes mounting in any round duct easy with these super-heavy duty retro-fit slip-in dampers
NOTE: All dampers subject to a 10% restocking fee.
With warmer weather approaching, upstairs or certain areas of your home can become uncomfortably warm without SmartZone. HVAC zone control can make the entire home more comfortable in the hottest Summer months.
Most homes with a single thermostat have some issues with keeping everyone, everywhere in the house comfortable. With SmartZone, thermostats are places throughout the home to achieve comfort everywhere... and if you choose to turn off some of the areas (zones), you can even save energy. Most importantly, however, SmartZone can make your home more comfortable than it is now. See the slides below for how it works.
How it works...
- SmartZone is connected to several Thermostats placed in "zones" throughout the home or building.
- SmartZone is connected to the Air Conditioning (AC) and Heating equipment.
- Dampers (air valves) are installed in the existing ducts that connect to room vents in the "zones."
- SmartZone controls the AC & Heating equipment AND opens/closes dampers to control air to the zones based on the thermostats.
There is obviously a lot more to HVAC Zone control than the above bullet points. Bypass & static pressure, duct sizing & damper leakage, thermostat & equipment types, equipment modes & changeover, compressor staging, emergency & auxiliary heat... and much more. The good news is that SmartZone takes the guess work out of the potential complications of zoning. Check out more about why SmartZone is the best choice here.