AGROTOP Poultry Construction Published by AGROTOP Marketing Department

Presented by Stanley Kaye Dropped Ceiling House and the Use of Attic Inlets Part 2. Ventilating thru the attic. . Presented by Stanley Kaye www.poultryconsultancy.com stanley@agrotop.co.il

Company Profile Specializing in agriculture turnkey projects, for poultry and livestock market, since 1989 Extensive experience with international poultry and livestock sector Erecting thousands of square meters of houses each year Cooperates with world's leading poultry and livestock equipment suppliers

The principle Uninsulated roof Layer of insulation

Attic Inlets

The principle 15 ° C Uninsulated roof Layer of insulation On a cold but sunny day the air in the attic will heat up.

Air in the attic is heated by sun Graph shows the temperature in the attic as opposed to outside over a week. This is a house with attic ventilation running- if the air had not been utilised but left to stand then the difference would have been greater.

Air in the attic is heated by sun .

The Principle Air in the attic is heated by the sun. In attic we have warmer drier air than outside Air from attic pulled into house thru ceiling inlets.

The advantages Saving in energy. As we are pulling in warmer air it is cheaper to heat that air (if needed) to temperature required in shed. Saving in We can ventilate more. This leads to better air quality, lower humidity and better litter. Better Results!!!!!!!!!!!!! Better Results = more

How much can be saved? Depends where and when:- Night no saving. Cloudy day little saving. Hot day no saving . Ideal savings- on coldish but bright day

How much can be saved? Study by Mike Czarick in Georgia. Compared 2 houses with attic inlets to regular. 6 sheds against 6 sheds. Experiment done in winter- outside temperatures from -15°C to 24 °C Findings:- Energy savings of 25% for inlet houses. The attic inlet houses were better ventilated during the day thus humidity was lower. Even during night humidity was lower- the drier litter in attic houses kept humidity lower and ammonia lower even at night.

Relative Humidity Comparison Relative humidity During the day was between 5 and 20% lower. At night the relative humidity was typicality 5% lower

Relative Humidity Comparison The farmer could “smell” the difference

Suitability dependent on the amount of usable sun For US maps exist of available solar energy for each month.

Suitability dependent on amount of usable sun

Suitability dependent on amount of usable sun The value of attic vents will vary according to area but it appears that in almost all of Australia there will be positive benefit.

Tips for good attic ventilation.

Control System To get the best out of attic inlets (and maybe to avoid damage) the shed needs to be well controlled. Modern Controllers such as the Rotem Platinum have ability to optimize use of attic inlets. Inlets should be operated thru the control system (i.e. attached to motor). Can be closed when not needed (eg tunnel ventilation and at night).

Which inlets- 2 or 4 way? In principle the 4 way inlet would be superior BUT To date there is no “controllable” 4 way inlet. Thus at moment the advantage is with 2 way controllable inlets.

2 way attic inlet

4 way attic inlet

How many fans? 2- 36 inch fans are normally enough to attic ventilate a 2500 sqm shed. When more ventilation is needed then the sidewall inlets are opened. Do not try to do all the minimum ventilation thru roof- we just want to ventilate thru roof enough to utilise the warm air.

Static pressure. Static pressure required when ventilating thru attic is low. (maybe half of that needed for sidewall ventilation. Air enters high up so no need to pull it far. The sidewall ventilation and the distribution fans are responsible for circulating the air, The attic system just has to bring the warmer air into house. When only 2 fans work the static pressure will open the attic inlets As more fans are added the static pressure will rise thus opening the sidewall inlets.

Tightness of house. Attic ventilation does not work in loose houses. When the fan tries to pull air from the attic it also pulls cold air from outside. This will cause more drafts- wet spots etc, So if your house is loose (if you turn on 2 36 inch fans with everything closed and you get static pressure less than 4MM water (40 Pascal or 0.16 inches water) then first make the house tight before you invest in attic ventilation.

Angle of inlets Very important not to create drafts. The inlet should be angled so air flows along ceiling and not down on birds. The higher the static pressure themo This is wrong. The air is being pushed down. The red deflectors should be removed or aimed along ceiling.

Suggested layout The roof inlets should not be pointed towards the sidewall inlets or this can cause dumping- ie the air is pushed downwards causing drafts and maybe cooling. The simplest way is that the inlets should be pointed along the length of the shed.

Temperature sensor in the attic Having a temperature sensor in the attic Is the key to control. The sensor should be shielded from radiant heat from the roof. If the temperature of the air in the attic is warmer than the air outside then the controller will increase ventilation. If the temperature of the air in the attic is above target temperature then ventilation can be constant. A simple and cheap shield made out of ping pong ball

Some useful control features The Rotem Platinum has some features that make controlling the attic ventilation very easy.

Final word The technology of attic inlets is relatively in its infancy. Tunnel ventilated houses have been widely available for about 25-30 years. Attic ventilated houses are still a minority and have been around for about 8-10 years. We can be sure that there will be many improvements in the future.

Final Final Word (: BUT!!!! There are real significant benefits that can be achieved today. Most of the cost of the system is in installing the ceiling. This will be necessary for any future system of attic ventilation.

Further information: Contact: stanley@agrotop.co.il www.poultryconsultancy.com www.poultryventilation.com www.poultryhouse.com

E-mail: agro@agrotop.co.il P.O.B. 150 Moshav Timmorim D.N. Shikmim Israel 79860 Tel. +(972)8-8611600, Fax +(972)8-8611601 E-mail: agro@agrotop.co.il www.agrotop.co.il