Guide Ventilation and Storage of Food (residential & commercial)


In old buildings without heat insulation potatoes, apples etc. can be kept for months in the cellar or a cool pantry. Warm, thermally insulated modern buildings require controlled ventilation systems to prevent excessive humidity in the stock room. This can be retrofitted even after the building has been finished.


Contents

  • Storage in the pantry
  • Humidification and dehumidification of the air
  • Temperature control by means of TDA fans
  • Pantries in modern buildings
  • Guidelines for industry and food processing

Storage in the pantry


Poisoning and illness caused by food (norovirus, salmonella) often trace back to poor cooling or excessive heating. Unfavourable temperatures are promoted by natural heat in the summer, heat buildup in the winter or heat emitted from electric appliances (e.g. refrigerator). The adjacent kitchen and other rooms such as the bathroom or laundry room release water vapour in the building which begins to condense on cold walls. Increased humidity is also caused by food that is heated up in the microwave or left on the table to cool down. More factors include cleaning the kitchen with a wet mop or cloth as well as fresh vegetables that exhales moisture.

Some edibles are loaded with microbes (bacteria) naturally due to their contact with soil (herbs), natural microorganisms (sprouts, seedlings) or their protein and water content (meat, fish). If the air stays hot and humid for extended periods of time, microorganisms and fungi quickly proliferate, their consumption can pose a risk to health. Larger organisms suchs as fruit flies are unhygienic as well, some fruit and vegetables from the supermarket might already contain larvae. Germ-transmitting insects can get into the pantry through windows for example. Apart from these microbiological factors, food is often contaminated with chemicals. Pesticides, preservatives and lacquers on the peel of fruit and vegetables exhale and worsen indoor air quality. Chemicals can also be of natural original. e.g. ethylene which is released by some root tubers and tropical fruits during ripening. Ethylene causes other food to ripen and overripe faster than normal. This can lead to decay and mould growth.

In old buildings natural ventilation in the pantry is easier done by windows or permanent openings (e.g. ventilation grilles, louvres). In contrast, the climate in modern (insulated) pantries is quite often less than ideal. Pantries that house electric devices or are warmed up by steam from the kitchen or solar irradiation need some sort of cooling. In the best case, the pantry is located on the shady side of the house with little contact with the sun. Ideally, there is a constant temperature and ventilation is provided in the evening/morning. The ideal case would be a pantry without any kind of heating at all or at the very least the temperature is lower than the rest of the house. Aim for about 5°C in winter and maximal 17°C in summer. Direkt solar irradiation through large windows, location on the sunny side of the building or passing heat pipes in the brickwork should be avoided. Furthermore, it is important to check for cleanliness and storage life of the goods on a regular basis. Smooth flooring such as linoleum and tiled walls are favourable choices because they are cleaned and sanitised quickly. The floor and shelves should be mopped and wiped regularly, however do not use too much water, otherwise humidity levels will be disturbed. The relative humidity should be around 70%. Regular ventilation prevents mould growth. Provided there is enough space, an additional ceiling fan ensures air circulation.


Ideal conditions in a domestic pantry:

  • dark, cool
  • consistent temperature and humidity levels
  • regular ventilation
  • no heating pipes
  • tightly shut door separates kitchen and pantry

Storage location

Conditions

Suitable for

Consider…

cellar, basement, 4 °C - 12 °C

Dark, cool, high humidity
Relative humidity about 80-90%
Location of deep freezer

Apples, potatoes, cabbage, onions, root vegetables, beverages, wine, boiled or pickled food, jams, bulbs and plants (overwinter survival)

Too far away for foodstuffs of daily use

Air out only in the morning/evening in summer to prevent damp air from causing condensation inside the pantry

Mouse and fly screens

Kitchen

High temperatures and humidity

Only foodstuffs that is packaged, dried or consumed quickly.
Lockable containers made from glass, metal, plastic.

Install extractor fan or fume hood

Insulated small room

Often next to warm, damp kitchen. Usually at room temperature, cooling requires energy input.

Packaged goods: flour, salt, sugar, cans, dried products, rice, pasta

No refrigerator due to heat emission (microwave causes humidity)

Pantry, no insulation or windows

Dark, chilled well

(Sprouting) onions and plants sensitive to light

Beverages

Extractor fan or ventilation duct with metal sheet cover,
Ventilation conduit etc.

Ensure shadow on the exterior wall

Pantry without insulation, with window

dark, cold, well-ventilated, slightly elevated humidity

Provisions insensitive to light, everyday consumables

Windows on the shady side of the house, flyscreen

Proper ventilation: windows not constantly open

Storage room, utility room, larder, 15 °C - 20 °C

Ensure air circulation with grids (be careful not to load too close to the floor)

Cleaning utensils, electric devices, personal belongings

Inline fan with backdraught flap
Ceiling fan or pedestal fan prevents stuffy air

Ventilation grille, door grille

Special refrigerator with different temperature zones

Cooler than storage room or cellar

Vitamines and minerals do not perish

Fresh fruit, vegetables, cheese, meat, fish

Store eggs separately

Pay attention to ethylene that is a byproduct of ripening (potatoes, tropical fruits)

Extended shelf life: What to do in addition to proper ventilation?


Use TDA, humidity and CO2 detector
If necessary, black out windows to prevent vegetables from sprouting
Install flyscreens
Consider best before dates
Get rid of spoiled and damaged food
Label pickled goods with the exact date
Use up old provisions, put new groceries in the back
Storage rack for improved air circulation
Airtight packaging against moths, flies, bugs…
Extraction hood in the kitchen
Separate clean and unclean areas
Clean earthy tubers and roots (they could harbour insects, mites, etc.)
Store prepared food in a cool and covered place, away from raw unprocessed foodstuffs
Do not keep transport boxes in the storage (bacteria)
Check humidity with a hygrostat
Keep microwave & refrigerator in the kitchen due to heat emission
Lime plaster/paint against mould

Humidification and dehumidification of the air


Fine dust is part of the breathing air when stocking flour (bakery, confectionery, commercial kitchen). These particles can irritate the lungs and trigger allergies. Controlled humidification can bind flour-dust and support cooling of meat for example. Automatic humidification with sensor technology ensures any desired pre-set humidity level. This protects inventory and employees against unnecessary pollution. Clean air and long service life of the technical device result in reduced expenses and fewer cases of illness among the staff in the long run. Another advantage: Dust-free appliances and tools require less cleaning and maintenance.

Drying: At home, pantries are often situated right next to the kitchen, often this room has a high amount of hot, humid air. If the connecting door is leaky or left open over extended periods of time, warm air from the kitchen will infiltrate the cooler pantry. Water vapour condenses and creates dew, supporting mould growth. If steam from hot food (microwave or cooked food in the process of cooling down) condenses, the pantry should be aired and dried additionally afterwards.

You can use electric dehumidifiers that collect water vapour in a catch tank. The filters inside modern appliances furthermore removes odour, small particulate matter in the air and partially even insects.

Temperature control by means of TDA fans


Due to heat in the summer and additional warmth from the heating system in the winter the temperature in the room can increase significantly.
Oftentimes, warm air will rise upwards where as cold air remains at ground level. This causes different layers of temperature in the room. Perishable eatables need constant temperatures though, the room should not heat up excessively in the summer. Opening the window (given the room even has one) might seem like a good idea at first, however there are drawbacks to it as well. On one hand opening a window does not give residents a possibility of controlling the temperature itself, furthermore residents need to be at home while the window is open. On the other hand, outdoor air can be humid or cause draught.

Most pantries however are not built facing the shady side of the house, do not have a window and are not heat-insulated. The solution is a fully automated temperature attenuation with TDA heat recovery. These device are activated by changes in temperature and maintain a constant indoor climate. They do this by preventing the aforementioned layers of warm and cold air because they circulate the air. This promotes shelf life and quality of stocked groceriers. In case there is some sort of heating device in the room, the emitted heat will be utilised more efficiently. In the end, this results in reduced heating costs. We recommend the TDA Nordik ceiling fan, it is available in different sizes and circulates air in small and spacious areas alike.

Pantries in modern buildings


In the past the cellar or pantry were the coldest rooms in the house. Modern, newly-constructed buildings with heat insulation are not designed to have cool spaces though. Even the cellar is often kept at room temperature. Nowadays, few people actively use pantries to their full capacities. With easily accessible supermarkets stocking goods at all times, groceries are taken home and stored in the refrigerator for a short time before being consumed. Once a new house has been erected, it is quite problematic to add a cool pantry due to present heat insulation. Nevertheless, architects are receiving more and more requests for undertakings of this kind. This is partially attributed to the current trend of DIY gardening, preserving and self-reliance. Some builders still have a desire for a pantry for nostalgic reasons or simply to keep the kitchen more organised. Random bottles, conserves and packages simply disturb the overall look of a modern kitchen.

Retrofitting a building with a pantry is possible, though a planner should be involved. If there already is a central ventilation system in the building it is important to consider all present air supply and extraction points. Determine what exactly you would like to store in the space. Should the small room be used as a storage room, e.g. for kitchen appliances, tableware or cleaning equipment that is used only on rare occasions? A refrigerator or other cooling appliance should not be kept in the pantry. These devices create heat of condensation that is passed on to the ambient air. If there is no other way and the refrigerator must be set up in the pantry, constant ventilation should be provided.
Sealed goods such as uncooked pasta and conserves can handle room temperature, but recently harvested eatibles from the garden must be stored in a cool and dark place. That is why implementing an additional room is not an easy project and requires careful planning. If the door is not airtight, hot and humid air from the kitchen might infiltrate the pantry. As a result, steam condenses inside the cool room. In turn, excessive moisture leads to mould. For the very same reason supply air to the pantry should not come from the kitchen.


The solution: Ventilation with heat recovery, for example from the Vents range.


Less invasive alternatives to a new pantry: Beverage crates and other tightly shut conserves can be kept in the basement, in the lower part of a shelf/larder without a back panel. Lockable larders in the house can be insulated from the inside to stay cold. If you are openly storing goods, try to ensure air circulation by leaving enough space between the items themselves and to the walls.
A garage or shed can also be used to stock groceries in the winter. However, the distance is too long for everday commodities.

Guidelines for industry and food processing


Guidelines such as HACCP and ISO 22000 regulate necessary equipment and conditions relating to ventilation and air conditioning in storage and shop facilities for unpackaged, perishable foodstuffs. Their aim is to preserve and protect edibles from contamination by microorganisms, odours and pollution due to dust during processing, transporation, storage and preparation in commercial and industrial environments.


The HACCP directive (Hazard Analysis Critical Control Point) requires control of food making, storage and sale. This protects consumers against microbiological, chemical and physical risks related to storage, post-treatment, packaging and distribution of groceries.



More information:
Ventilation in agriculture
Ventilation in greenhouse