AVI Hood Features

Why the AVI Hood Saves You Money
How the AVI Hood Saves You Money
How the System Works
AVI Hood Operational Functions
The AVI Hood as a System
Makeup Air (MUA)
Possible Downside
Likely Ordering Scenario
Third-Party Results

Why the AVI Hood Saves You Money

Since the AVI Hood operates at full capture and containment at such low exhaust rates, operators get very quick paybacks. The first cost of the AVI Hood may be higher than some exhaust-only hoods in the market; and lower than many of the compensating or short circuit hoods available today.

Beyond the first cost and obvious savings, there are unseen benefits that many operators now understand. Using the AVI Hood system with proper MUA, kitchen spaces will remain comfortable to the benefit of all employees. Kitchens, and especially pizza kitchens, have been known to be extremely hot and uncomfortable to work in. The AVI Hood system captures all the heat from the oven, except for small amounts of radiant heat, and effectively ventilates it.

Another cost-savings benefit of the AVI Hood is no more yellow ceiling tiles. It’s clear when looking at ceilings around pizza ovens if a hood is working properly. With the AVI Hood’s unique full-panel design surrounding the ends of the ovens, all the grease and heat is captured and removed from the operating space.

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How the AVI Hood Saves You Money

It’s important to understand that there are many variables in calculating cost and potential savings. Things like actual weather conditions at location, how many windows and which direction they face, building construction, how many people are working, how much equipment is operating, and a host of other factors will affect payback and operating costs.

The largest savings is related to the lower CFMs at which AVI Hoods can operate. National estimates for the cost of heating and cooling 1 CFM of air annually range from $1-$2 per year depending on location. The other savings come from downsized equipment, ductwork, smaller fans, and lower install costs.

The AVI hood over a double stack of XLT ovens is UL listed to need only 828 CFM of exhaust air. Other hood designs range from 1628 to a high of 2200 to remove all the heat from the same ovens. By using the AVI Hood system, there is approximately an 800 CFM reduction.

Actual savings will depend on variables listed above. The bottom line is that a new AVI Hood will save money in the long run, but more importantly, will help keep operator’s pizza shops cool in the summer and just right in the winter. Lastly, the hard to calculate savings are listed below.

1.    With no yellow ceiling tiles to clean, hundreds of hours and dollars in labor are saved a year
2.    Less employee turn-over as the store is comfortable to work in
3.    Less food spoilage and dough loss
4.    Less noise with the AVI Hood’s smaller exhaust fan
5.    Quieter oven by shrouding the oven ends and using XLT’s Quiet Fire burner

Click here to contact your AVI salesmen

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How the System Works

The AVI Hood is a Type I hood with grease filters built to the UL710 standard. It is used over a conveyor pizza oven, which is classified as a medium-duty appliance. By code, using this AVI Hood, operators will most likely need a fire suppression system and MUA - makeup air - that matches the exhaust rate.

The interpretation of these codes is often different from community to community. It is up to the end user to check with local code officials to determine rules and regulations.
XLT, manufacture of the AVI Hood, is an authorized installer and seller of Ansul fire suppression products. With XLT, operators can save money by ordering known fire suppressions with an order of AVI Hoods.

XLT will install the piping, nozzles and other items needed. When the system is on-site, a local Ansul installer will finish the job by mounting the system box, checking the remote pulls and gas shut off, and starting and checking the system. If operators wait until ovens and AVI Hoods are on-site they risk paying much more and having an installer who may not know the best way to pipe the system.

The Food Service Technology Center (FSTC), in conjunction with Fisher Nichol Consulting, offers industry-leading advice on many foodservice equipment issues. Below is the link to three excellent design papers that every operator, designer and builder should read.

http://www.fishnick.com/equipment/ckv/designguides/

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AVI Hood Operational Functions

The AVI Hood has been designed to accommodate every pizza operation. By simply building the panels to each customer’s specifications, owners can load and unload in any way needed. When ordering a new AVI Hood, just let XLT know what type of configuration is desired, and XLT will build it that way. If the system is moved at a later date, the panels can be re-configured in the field.

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The AVI Hood as a System

The AVI Hood and XLT ovens are listed together for UL compliance. This makes official code more streamlined as the oven and hood are listed together as an approved system.

In the past, pizza ovens have been considered a bakery appliance and in many places exempt from Type 1 hoods and fire suppression. Today, the codes have been combined and pizza ovens have been reclassified. The best way to know what type of hood or fire suppression system is required is to ask your local code officials, fire department and/or building department. Make sure to ask these questions before ordering ovens and hoods.

What code officials may read:

American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE)

ASHRAE Standard 154: Lists conveyor pizza ovens as a medium-duty appliance.

International Code Council (ICC): Building codes distinguish between cooking processes that create smoke and grease and those that produce only heat and moisture. Essentially two types of hoods are available.

Type I Hood: Needed for cooking that produces smoke and grease. Requires liquid tight construction with built in fire suppression system.
Type II Hood: Needed for operations that produce only heat and moisture, do not require liquid tight construction or fire suppression system.

International Mechanical Code (IMC):

Section 507
Commercial Kitchen Hoods
507.1 General.
Commercial kitchen exhaust hoods shall comply with the requirements of this section. Hoods shall be Type I or II and shall be designed to capture and confine cooking vapors and residues. Commercial kitchen exhaust hood systems shall operate during the cooking operations.
507.2.1 Type I Hoods. Type I hoods shall be installed where cooking appliances produce grease or smoke. Type I hoods shall be installed over medium-duty, heavy-duty and extra heavy duty cooking appliances. Type I hoods shall be installed over light-duty cooking appliances that produce grease or smoke.

Section 508
Commercial Kitchen Makeup Air
508.1 Makeup air.
Makeup air shall be supplied during the operation of the commercial kitchen exhaust systems that are provided for commercial cooking appliances. The amount of makeup air supplied to the building from all sources shall be approximately equal to the amount of the exhaust air for all exhaust systems in the building. The makeup air shall not reduce the effectiveness of the exhaust system. Makeup air shall be provided by gravity or mechanical means or both. Mechanical makeup air systems shall be automatically controlled to start and operate simultaneously with the exhaust system. Makeup air intake openings shall comply with section 401.4.

508.1.1 Makeup air temperature.
The temperature differential between makeup air and the air in the conditioned space shall not exceed 10o F except where the added heating and cooling loads of the makeup air do not exceed the capacity of the HVAC system.

Section 509
Fire Suppression Systems
509.1 Where Required.
Commercial cooking equipment appliances required under Section 507.2.1 to have Type I hood shall be provided with an approved automatic fire suppression system complying with the International Building Code and the International Fire Code.

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MUA – Makeup Air

Lastly MUA - makeup air - needs to be addressed and designed for. Per the International Mechanical Code rules, operators need to have MUA within 10oF of the conditioned space air. XLT recommends two methods to achieve this.

Preferred MUA method

Take full MUA needed from new or existing roof top mounted packaged HVAC unit. The unit will require an out side air economizer that can be set to bring in the correct amount of out side MUA. This air will be treated by the HVAC unit and be of comfortable temperature. The HVAC contractor can advise on how to accomplish this and meet the local community codes.

Issues

The HVAC unit will always have to be on when the hood is on, so MUA can always be provided. A fixed outside air damper or a motorized economizer will be needed to allow the correct CFM airflow of outside air. There will be times when HVAC may not be needed as the outside temperature is already comfortable, yet the unit will still have to be on. The good thing is the heating or cooling portion will not be needed, just the fan portion to bring in MUA. During closed hours the HVAC unit can be operated by set point only. The HVAC package unit may have to be interlocked to the hood controls per the local code. This ensures that when the exhaust fan is turned on, the MUA must be turned on. The oven function will, in most cases, also have to be interlocked to the exhaust fan. This means when turning on the ovens, the exhaust fan also turns on automatically.

Alternative MUA method

Provide a dedicated MUA unit with cooling and heating that uses 100% outside air and matches it to the exhaust fan rates. The unit is going to be interlocked with the exhaust fan, so when turned on, the MUA unit is also on. This is the most expensive way to bring in MUA, yet in the long run, can be the most efficient method. The units are only on when the hood is on and the air they bring back is a comfortable temperature. Most states require heated air. Operators can purchase the systems without the air conditioning coil, but it is not recommended. As with the packaged HVAC unit, the ovens may be required to be interlocked to the exhaust fan operation. This means when the ovens are turned on, the exhaust fan also turns on automatically.

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Possible Downside

These units and associated installation will add 8-12K of added first-time cost to the operator. In practice, the operating costs are generally less than the HVAC method. The upside is that the kitchen will always be comfortable no matter the outside conditions or how many ovens are operating. It’s very common with an HVAC packaged unit that a repairman may close the outside air dampers down to make the unit work better. On a dedicated MUA unit there are no dampers to close or set.

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Likely Ordering Scenario

The AVI Hood has two major parts. The top hood portion, hung during build out, and the hanging skirts or panels, installed when XLT ovens are delivered and installed.

The top portion of the AVI Hood will need to ship to the job site earlier in the build out. Any fans, curbs, or MUA units will also need to ship or be installed early at the site. Once the building site is ready for the ovens and hood panels, this can be scheduled with the XLT out-bound transportation department.

Hoods should be ordered in advance of ordering ovens.

Main top portion of the AVI hood is drop shipped in during the build out. It is crucial that it be hung exactly 69 5/8th inches above the finished floor.

Roof curb and exhaust fan installed on the roof prior to your ovens being delivered.

When your store is ready for the ovens and the hanging panel your delivery can be scheduled with the factory. Ovens will be installed under the already installed hood.

Once the oven is correctly positioned the hanging panels will be installed.

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Third-party Results

The AVI Hood has been third-party tested and proven to be the best operating exhaust-only hood for conveyor pizza ovens - in the world!

Below are the exhaust rates for each hood system:

The AVI hood was tested by a third party at the Commercial Kitchen Ventilation (CKV) Lab in suburban Chicago for performance. The hood was also tested by ETL for compliance to UL 710. Below is the summary conclusion from the final report from the CKV Lab and a link to the complete report.

XLT Ovens’ 3255-TS conveyor pizza oven and hood system performed well under the rigorous conditions of the ASTM F-1704-05 Standard Test Method for the Capture and Containment Performance of Commercial Kitchen Exhaust Ventilation Systems. When optimized with integrated panels and improved food take away trays, the required ventilation rate was as low as 200 cfm for the top deck operation. With all three decks in operation, the required exhaust rate was 1100 cfm.

The optimization of the hood and appliance as a system significantly reduced the required exhaust rate. Without the optimization of the integral panels, 2400 cfm was needed for proper ventilation of two-deck operation. With the panels installed and the food take-away trays removed, the exhaust rate was reduced to 700 cfm, which is a reduction of 1700 cfm, or 71%. The combination of an excellent conveyor pizza oven, close-coupled eyebrow hood, and carefully engineered integration of the two devices has resulted in an efficient system that can deliver a high quantity of pizza while operating with a very low quantity of exhaust.

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AVI Hood Spec Sheet
Click here to download AVI Hood Spec Sheet.