Natural and Mechanical Cooling Methods for Farm and Homestead Storage Chris Chaisson Kirk Jones

Cooling Systems – Natural to Mechanical• Ground temperature

• Spring water

• Ice

• Outside Air

• Passive venting air exchange

• Active venting air exchange

• Commercial refrigeration

• Controllers

• Freeaire controller – active air/commercial refrigeration

• Coolbot controller – controlled window AC

• Callahan’s Farm Hack system

• myDTC – DIY active air

• myWebController – DIY active system

• Co gen/tri-gen – using heat to cool

• Future Systems/Future needs

Why Natural or Mechanical?

Seasonal Storage (cool seasons)

• Vents

• Fans

• Freeaire Polar Package

Year Round Storage

Ice

Compressor

walk-ins

Coolbot

Mix: Freeaire/conventional

vents and coolbots

Co/Trigeneration

absorption refrigeration

Which one is better? For whom?

• Wine- Cellar- mechanically controlled

• Cheese- Cellar- mechanically controlled

• Homestead – Small root cellar/Ice

• Farmstead – large root cellar/Ice

• Farm/CSA/Institution- Root Cellar/Walkin

• Small markets- Free aire/Compressor/Cellar

Important Post-Harvest Care

• Produce should be harvested

when cold

• Harvest as late in season

• Naturally seasoned

vegetables store longer and

better

• Brix content will be higher

• Remove field heat

– Hydro cooling

– Use mechanical systems

Field heat

Traditional In-Ground StorageCitrus fruit storage cave in Cappadocia, Turkey

Women culling lemons and repackaging for shipment

Spring House for Cold Storage Denning, Ulster County, New York

Community ice harvests

Ice in Colonial America

Thompson's Ice HouseSouth Bristol, Maine

Ice Options now

•Cutting and hauling• Forming in place

•Storage Designs• Below or above ground• Sawdust or wood shavings• Vents and drains• Gravel/permeable floor• Thermal mass stone/concrete walls

Rainbow Heritage

The cave construction 1

Cave construction 2

Cave construction 3

Cave Construction 4

Ice in Harvest

• Tapered plastic tubs

• -20F is ideal

Ice in theCarrot Cave

Ice thermal values•Thermal Conductivity, 2.2 W/m-K•Heat capacity, 2.1 kJ/kg-K•Heat of Fusion, 333.55 kJ/kg

Passive venting a root cellar•4-6” PVC S+D

•Warm air escape at

ceiling

•Cold air entry 6” above

floor

•Vent through existing

window w/ insulation

and plywood

•Hardware cloth and

screen against insects

and rodents

•Close in Winter

Adamah Adam

Venting details

120 CFMSimple in-line fan

and damper

Active Venting

Dampers and duct fans

Spring loaded 4” backdraft dampers, $20 each

4” In-line duct fan, $29 ea

Adamah Retreat Center

Mechanical cooling – refrigeration

• Compressor

• Absorption refrigeration

• Biogas, wood cogen (furnace, kiln), solar –solar during day and propane at night

• Modify and mix

• Coolbot - Cheaper situation that uses an air conditioner

• Freeaire

FreeAire System

FreeAire components

Web Interface

FreeAire Benefits

• Cooler Controller Capabilities – Year Round Savings– Controls Compressor run time: Reduces energy consumption & wear and tear. – Controls Evaporator Fan run time: Reduces energy consumption, reduces heat introduced

into cooled spaces & wear and tear. – Defrost Cycle Management (both air and electric defrost cycle): Reduces energy

consumption, reduces heat introduced into cooled spaces. – Data Logger: Keeps a downloadable record of system component runtime and energy

consumption & savings.

• Cooler Controller Capabilities – Year Round Savings with Optional Features– Monitors & Manages Door Heater Operation: Reduces energy consumption, reduces heat

introduced into cooled spaces. – Humidity Monitoring: Monitors and controls humidity levels in cooled spaces and ensures

that humidity levels stay within a user selected range. – CO2 Monitoring: Monitors CO2 levels and can cycle fresh outside air into a cooled space (with

Polar Power package).

• Cooler Controller Capabilities – Maximum Savings with Polar Power (In Winter)– Uses outside air for cooling when conditions allow (in conjunction with Polar Power

package): Turns off conventional mechanical refrigeration system components, reduces heat introduced into cooled spaces, system wear and tear & dramatically reduces energy consumption.

Chris Callahan (UVM AgExt)Outside Air Hack

Set the Temperature between 35 and 40F

Drumlin Farm Service Barn (MassAudubon)

Root cellar below, seed and squash storage above

Renovating main floor into classroom addition

Insulating South wall, with newer windows

Root CellarCold and Moist Chambers

Squash Room and Seed Storage

Drumlin Cellar Venting

Drumlin Cellar Electrical

Drumlin Attic Venting

Drumlin Attic Electrical

myDTC8

Powisset Barn Crop Storage

Powisset Crop Storage – Design Phase I

Powisset Barn – Trustees of Reservations

Powisset – Design Phase II

myWebController.comWebRelay-10

Coolbots

• More efficient above 35F if well insulated and doors stay closed

Cogeneration –Combined Heat and Power

Trigen systems

Absorption chillers

• Very Compact

• Few mechanical parts

• Low maintenance

• Runs on waste heat

• Reduces overall fuel use and electricity consumption

Traditional RV Schematic

Promising Technology

“Small-scale trigeneration system offers hope for refrigeration in developing world” Refrigeration and Air Conditioning Magazine, 2014

“All-in-one energy system offers greener power for off-grid homes, farms and businesses” Engineering and Physical Sciences Research Council, 2014

Thank You!!

Contact us:Chris@WholeFarmServices.com802-777-3537

KirkJ@WholeFarmServices.com510-697-7790