Deep freezer: units per month in Pakistan
Short answer. A chest deep freezer drawing about 250 watts with the compressor on for around 14 hours of a summer day uses roughly 3.5 units daily and 105 units a month. Upright freezers of the same capacity run noticeably more, because cold air falls out of the cabinet every time the door opens.
Power draw
- Low: 150 W
- Typical: 250 W — the figure used in every calculation below
- High: 450 W
Chest freezers sit lower in the band than upright ones of the same capacity, and both draw a large starting surge.
Units and cost by usage pattern
Each row is 250 W × the hours shown ÷ 1,000, over 30 days. The three cost columns exist because the rupee cost of a unit depends entirely on which slab your month lands in — the same consumption costs a light user and a heavy summer household very different amounts. Rates are illustrative and not a substitute for the tariff table printed on your own bill.
| Usage pattern | Units / day | Units / month | At Rs 12.5/unit | At Rs 27.5/unit | At Rs 36/unit |
|---|---|---|---|---|---|
| Chest freezer, winter (compressor on ~9 hours) | 2.25 | 67.5 | Rs 844 | Rs 1,856 | Rs 2,430 |
| Chest freezer, summer (compressor on ~14 hours) | 3.5 | 105 | Rs 1,313 | Rs 2,888 | Rs 3,780 |
| Upright freezer, summer (compressor on ~17 hours) | 4.25 | 127.5 | Rs 1,594 | Rs 3,506 | Rs 4,590 |
Rate bands: Rs 12.5 — light user, protected (≈150 units/month); Rs 27.5 — average household (≈250 units/month); Rs 36 — heavy summer month (700+ units). This appliance is seasonal — the usage patterns above assume 6 months of the year at most, so the annual figure is lower than twelve times the monthly one.
Chest versus upright
Cold air is dense. In a chest freezer it sits in the box when the lid opens; in an upright freezer it pours out of the door and is replaced by warm room air that then has to be cooled again.
That single physical fact accounts for most of the difference in running cost between the two designs, and it is why shops running an upright display freezer pay so much more than a household with a chest.
What frost costs
Frost is an insulator on the inside of the very surface that is supposed to absorb heat. A centimetre of build-up measurably lengthens compressor run time, and several centimetres can raise consumption by a quarter.
Manual-defrost freezers are more efficient than frost-free ones in principle, because frost-free models run a heater periodically to clear the evaporator. That advantage disappears entirely if the manual one is never defrosted.
Load shedding and thermal mass
A full chest freezer holds safe temperature for well over a day without power. A half-empty one loses temperature far faster, because air holds almost no thermal energy compared with frozen food.
Filling empty space with sealed bottles of water is a genuinely effective measure in a load-shedding environment, and it also reduces cycling in normal operation.
How to use less
- Defrost when frost reaches about a centimetre — twice a season is usually enough.
- Fill empty space with water bottles; it costs nothing and reduces both cycling and outage losses.
- Site it in the coolest room you have, never in a sun-facing verandah or beside a cooker.
- Check the lid seal the same way as a fridge gasket, with a currency note.
Frequently asked questions
Is it cheaper to run one large freezer or two small ones?
One larger unit, almost always. Surface area per litre falls as capacity rises, so a single big freezer loses less heat than two small ones holding the same volume, and there is only one compressor to run.
Should I unplug the freezer when going away for a month?
If it is empty, yes, and leave the lid ajar to prevent mould. If it is full, emptying it to save perhaps 100 units is rarely the better trade.
Compare with
- Refrigerator — 160 W typical
- UPS / home inverter — 180 W typical
Filed under refrigeration in the full appliance index. Add your own hours in the consumption calculator, or open your actual bill with the reference number lookup.