Heating a tiny shed

[copytmpmzl]

I have a wooden garden shed about 6m x 4m with walls and ceiling reasonably well insulated. I use it for several purposes – seed house, vegetable production, 8 stacking wormeries, wine cellar and some general storage. It is quite full, so little empty air space, or spare floor space.

I presently use a permanently switched on 1.5kW fan heater at floor level on a very low setting and it is sufficient to maintain 14º to 15ºC (just below 60F) most of the time. It operates only infrequently during the day. The temperature does drop on cold nights (only very slight frosts now and again), but a max/min shows it has not gone below 12.3º in over a year at distance from the heater. That is acceptable for everything in there. Daytime requirements will be less than the 1.5kW.

I am in the process of switching electricity tariffs so that I have a reduced rate from 00.30 to 7.30 a.m. My idea is to continue using the fan heater during the lower rate electricity time as well as making use of this time for my LED grow lights. I want the fan in use because it blows warmer air around the wormeries when on and this raises their temperature above the ambient air temperature in the shed and they are doing OK.

I wondered whether it would be feasible to charge a battery for the 7hrs when electric costs are lower, then use that stored power for an oil filled radiator even for part of the remaining time. This is the only question I want to be answered, and I ask it because I have no experience of using battery storage. Just think cents instead of pence, and the prices are 16p and 33p/kWh. I would need to buy an inverter and battery, but have a radiator that I could use.

I have posted the foregoing information on dedicated sites, but nobody has answered the question, they just want to tell me all sorts of things I did not ask and make suggestions for alternative heating methods – all of which I either cannot have or do not want epoxy garage floor Atlanta. If it is not feasible then I will just stay with what I use at present and experiment with the radiator on a low setting and time switch for during the day.

Please do not waste your time on giving me other ideas. What I have and do does not warrant capital expenditure. The shed is organised in such a way that fixed storage heaters, fires, stoves, heat pumps etc. cannot be used. It needs to be small and mobile, hence the radiator idea.

I'm planning to convert a 12x16 ft shed into a weekend 'hunter's cabin' for when I spend time on my wooded property. Winters get pretty cold (and summers hot) here in middle Georgia so I need to get an off grid option for heating the shed. The options I'm thinking of include: either propane wall-mounted heater or a small wood burning stove. The propane heater seems easy and propane can also power a small refrigerator if I decide to get one. The wood stove means paying for installation and keeping it stoked but firewood is plentiful. Any one know what labor costs could be to get a small stove installed? Any recommendations on which would be better choice.

 

[LouNY]

Firewood is "inexpensive" it seems but then remembering to get the chimney cleaned and if you use the triple wall pipe through the building and up it adds up the cost quite rapidly.
A infrared propane requires no venting.

 

[Jstpssng]

Propane isn't cheap either and if you are planning on one of those unvented heaters, I would not want it in a well insulated building where I am going to be sleeping. A chimney is going to cost you about as much as the heater and tank, and it doesn't take much effort to run a brush through it every couple of months.

For comparison I just have a small 12x32' building I am living in until I get money to pour a foundation and build... I burn >2 cds per year and heat it with a small oil filled radiator when I'm away. That heater is on a thermostat and costs me about 10-20$ per month through the winter.

 

[dstig1]

This is the only question I want to be answered, and I ask it because I have no experience of using battery storage. Just think cents instead of pence, and the prices are 16p and 33p/kWh. I would need to buy an inverter and battery, but have a radiator that I could use.

I have posted the foregoing information on dedicated sites, but nobody has answered the question, they just want to tell me all sorts of things I did not ask and make suggestions for alternative heating methods

Thank you for the good LOL!

But seriously now - I will have you know that this request violates TBN Statute 126.34.2 "Mandatory thread drift process" and Statute 293.6.2 "Disallowance for Respondents actually reading the OP". Since this appears to be your first offense, the fine will likely be reduced. Please report to TBN court for your hearing next Monday.

 

[OldMcDonald]

Armed with the practical experience and theoretical knowledge of responders from several countries on different forums, I have reached the conclusion that my idea is feasible. Whether it is economic is a question that needs a great deal more thought.

Given all the uses of the shed, the most important is maintaining the temperature of the wormeries and containers for seeds and seedlings, each individual ideal being different.

Thinking about the problem, I suddenly recalled Fourier and his Law regarding heat (or cooling) conduction from the ground to the air above it. Many people will know of Fourier from “the greenhouse effect” which keeps earth at a liveable temperature. From farming around the world for longer than many people live I was well aware of this conduction and have used the principle, but had foolishly forgotten about it. In practical terms I can accept a lower air temperature without affecting the plants.

There is a lot of bulk in the shed – maybe two thousand litres of moist “soil”, with a fair bit of the rest of the interior being timber staging and shelves for the plants; storage boxes full of various materials; tools and equipment; water for the plants and soaking corrugated cardboard – large quantities are used in the wormeries and garden. All in all a lot of material that could lose some temperature without doing any harm.

The decomposition of organic materials added to the wormeries (vegetable waste and cardboard) means the temperature of the contents is higher than the air, and this temperature differential is further increased with warm air blowing onto the wormeries from the fan heater. There is some conduction from them when the heater is not on. I need to do some experimentation to see the effect on the soil temperatures of the wormeries and plant containers. I have 1.5kW and 3kW available on the fan heater and 750W, 1250W and 2kW on the radiator so a few combinations that can be tried on low and standard tariffs. This will take time.

The economics of battery storage will be determined by how much electricity I could save. Heat is needed for about 30 weeks a year, so a saving of even £1 a day on electricity costs is worthwhile, but it might not be possible.