Freezer minimum temperature

Energy efficient construction methods and insulation
Post Reply
Djs63
Posts: 36
Joined: Mon Mar 07, 2022 3:49 pm
Location: NE England

Freezer minimum temperature

#1

Post by Djs63 »

Looking to replace freezer with better energy usage but:

They’ve changed the energy classification so that old A++ is now F, I think!, confusing.

And most seem to warn against siting in out buildings ‘cos they need a ambient temperature greater than 10C. In my simple mind, if it is colder outside the freezer surely it has less work to do?
Proven 6 kWh max turbine, PV 8 KW solar hot water (15 evacuated tubes). Kia eNiro and MG Z5 EV, triple glazing, ground source heat pump and wood stove , Solax PV 5.8 kWp and 17 kWh lithium battery, 5600 litres rainwater storage
Oliver90owner
Posts: 397
Joined: Wed Jun 16, 2021 3:48 pm

Re: Freezer minimum temperature

#2

Post by Oliver90owner »

It is all to do with how the thermostat works. They have a minimum temperature specified for proper operation.
Marcus
Posts: 261
Joined: Mon Nov 08, 2021 6:25 pm

Re: Freezer minimum temperature

#3

Post by Marcus »

There was a issue with some fridge-freezers which used a single compressor and thermostat (in the fridge) to control the temp of both parts: if they are placed in an ambient temp below fridge temp then they don't turn on and the freezer defrosts.

Fridges and freezers are nominally designed for a particilar climate- if you look on the back they will have a climate category: N, SN, T, ST - normal, subnormal, tropical, subtropical. Some freezers will show just one category,
some list all. Theoretically if you run a freezer in a temperature below that it is designed for the refrigerant and lubricant could run too cold and not do their jobs properly, reducing efficiency or damaging the freezer.

In practice they're normally fine in an outbuilding, but if in doubt you could contact the helpline of the manufacturer of the freezer you're considering and ask them directly. I did this the last time i bought a freezer as it arrived with a ST climate designation (in Wales! ) they said it woukd be fine in an outbuilding and, so far, it has been (3yrs).
450W hydro-electric
5110W pv
1.3kw Wt2 - not yet producing
6kWh lead acid - maybe 1kwh useable
LiMnCo battery made from 2nd hand hybrid car modules 3.6kwh nominal 24v.
300lt hot water tank and two storage heaters
ASHP Grant Aerona 3 10.5kw and UFH
Djs63
Posts: 36
Joined: Mon Mar 07, 2022 3:49 pm
Location: NE England

Re: Freezer minimum temperature

#4

Post by Djs63 »

Thank you, Marcus, I will try to find out more from the sales pitches. David
Proven 6 kWh max turbine, PV 8 KW solar hot water (15 evacuated tubes). Kia eNiro and MG Z5 EV, triple glazing, ground source heat pump and wood stove , Solax PV 5.8 kWp and 17 kWh lithium battery, 5600 litres rainwater storage
CrofterMannie
Posts: 101
Joined: Sun Jun 13, 2021 5:29 pm

Re: Freezer minimum temperature

#5

Post by CrofterMannie »

Some manufacturers specifically rate their freezers for use in outbuildings (so are rated to use to -15C).
From memory we bought Beko ones for that reason
8kw solar
ETA log boiler
5ha woodland
MG5EV
Post Reply