Solutions for loadshedding

[Let's Ride]

and that just so that he can run his kettle

Not even.

[Vetplant]

I'm pondering actually to add another 1kw of solar dedicated to run a heating system for winter.  Basicly get element and run direct from solar. Heat up a stack of bricks and let it radiated during the night.

 

In theory brick takes about 4 hrs to transfer heat from one side to the other, so if you heat the stack of bricks  from center, by evening it should be hot outside...   

 

Wood is now so @#$# expensive here that solar might be cheaper . ....

Came across this resource for all things Solar DIY.

https://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm

Plenty of ideas and concepts to consider.

 

I do think going for a Passive system is safer, all things considered. Although your Hot Brick Stack is probably cheaper, having wires and thermal pads with high temperatures is a bit more risky than  a passive system with zero wiring.

 

Our biggest challenge is that our neighbour to the West has some massive trees, which essentially shades all our bedrooms from about 2PM. So I need to get my Thermal Mass warmed up before then.

[Karman de Lange]

Came across this resource for all things Solar DIY.

https://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm

Plenty of ideas and concepts to consider.

 

I do think going for a Passive system is safer, all things considered. Although your Hot Brick Stack is probably cheaper, having wires and thermal pads with high temperatures is a bit more risky than  a passive system with zero wiring.

 

Our biggest challenge is that our neighbour to the West has some massive trees, which essentially shades all our bedrooms from about 2PM. So I need to get my Thermal Mass warmed up before then.

 

 

Ja, seen that page a few times, the problem with that page is that it was written when PV panels was still expensive.  

 

There nothing dangerous about brick stack. The voltage is 12-60V depending on how you configure it.  Of course you run normal fuses/breakers for dead shorts.    Add safety thermostat and its less dangerous than chineese oil heater.  There is no high voltage involved, no electronics (maybe on/off switch). its fairly passive system actually. 

 

Other thing with PV is, if you need more, you just go to local shop, and buy another panel.  If don't work, you sell it again on gumtree.

 

The only other viable option for us is those tin can solar heating.. but we don't have enough wall space for enough surface area and also don't have enough space for massive thermal mass inside...   

 

With solar heating you need large mass storing low temperatures.  with PV heating system you can go very high heat, so low mass is fine....

 

guess its all a trade off at end of the day...

Edited April 15, 2021 by Karman de Lange

[Vetplant]

Something to consider:

 

Heating of anything with a resistive coil will only ever be 100% efficient, it cannot be more.

 

ie: A Coil that consumes 1000W of electricity will only ever heat a room at 1000W, nothing more. (Lets ignore losses just for a moment)

 

A heatpump on the other hand, like an air-conditioner. Can move more heat than the electricity it consumes.

 

My 14 000 BTU (roughly 4kW of heating or cooling) aircon consumes just north of 1kW of electricity. So I am currently running my house on a trial where I switch the Aircon on maximum heating as soon as my solar batteries are fully charged(around noon) until the solar supply dries up.

 

This way, I preheat my entire Bedroom section of the house before bedtime with about 4kw of heating for three hours.

 

Currently we are sleeping relatively cozy. But I do think we still have some opportunities to improve the insulation in the bedrooms to improve the retention of that heat through the night.

[Karman de Lange]

Something to consider:

 

Heating of anything with a resistive coil will only ever be 100% efficient, it cannot be more.

 

ie: A Coil that consumes 1000W of electricity will only ever heat a room at 1000W, nothing more. (Lets ignore losses just for a moment)

 

A heatpump on the other hand, like an air-conditioner. Can move more heat than the electricity it consumes.

 

My 14 000 BTU (roughly 4kW of heating or cooling) aircon consumes just north of 1kW of electricity. So I am currently running my house on a trial where I switch the Aircon on maximum heating as soon as my solar batteries are fully charged(around noon) until the solar supply dries up.

 

This way, I preheat my entire Bedroom section of the house before bedtime with about 4kw of heating for three hours.

 

Currently we are sleeping relatively cozy. But I do think we still have some opportunities to improve the insulation in the bedrooms to improve the retention of that heat through the night.

 

 

deleted

Edited May 4, 2021 by Karman de Lange

[Karman de Lange]

Something to consider:

 

Heating of anything with a resistive coil will only ever be 100% efficient, it cannot be more.

 

ie: A Coil that consumes 1000W of electricity will only ever heat a room at 1000W, nothing more. (Lets ignore losses just for a moment)

 

A heatpump on the other hand, like an air-conditioner. Can move more heat than the electricity it consumes.

 

My 14 000 BTU (roughly 4kW of heating or cooling) aircon consumes just north of 1kW of electricity. So I am currently running my house on a trial where I switch the Aircon on maximum heating as soon as my solar batteries are fully charged(around noon) until the solar supply dries up.

 

This way, I preheat my entire Bedroom section of the house before bedtime with about 4kw of heating for three hours.

 

Currently we are sleeping relatively cozy. But I do think we still have some opportunities to improve the insulation in the bedrooms to improve the retention of that heat through the night.

 

 

o, our 18000 btu inverter aircon only uses ~1.8kw at max power.   I think its chinese BTU's

[Eddy Gordo]

Something to consider:

 

Heating of anything with a resistive coil will only ever be 100% efficient, it cannot be more.

 

ie: A Coil that consumes 1000W of electricity will only ever heat a room at 1000W, nothing more. (Lets ignore losses just for a moment)

 

A heatpump on the other hand, like an air-conditioner. Can move more heat than the electricity it consumes.

 

My 14 000 BTU (roughly 4kW of heating or cooling) aircon consumes just north of 1kW of electricity. So I am currently running my house on a trial where I switch the Aircon on maximum heating as soon as my solar batteries are fully charged(around noon) until the solar supply dries up.

 

This way, I preheat my entire Bedroom section of the house before bedtime with about 4kw of heating for three hours.

 

Currently we are sleeping relatively cozy. But I do think we still have some opportunities to improve the insulation in the bedrooms to improve the retention of that heat through the night.

Do you have double glazed windows? Something I am looking at doing in our bedrooms. 

[Vetplant]

o, our 18000 btu inverter aircon only uses ~1.8kw at max power.   I think its chinese BTU's

   

 

Mine is Goldair, non-inverter. So most likely also just Chinese with a sticker on it.

 

But when it is running at full blast it really throws that Warmed Air. Way more than any of these resistive heaters could do for the same electricity consumption.

[Vetplant]

Do you have double glazed windows? Something I am looking at doing in our bedrooms. 

Nope.

 

Heard quotes of around R80k to do an "average sized" home.

 

No thanks, maybe just get the missus to buy nice thick curtains and put that old-school Curtain Box Pelmet on top of the curtains to make my own insulation box in front of the windows.

[Karman de Lange]

   

 

Mine is Goldair, non-inverter. So most likely also just Chinese with a sticker on it.

 

But when it is running at full blast it really throws that Warmed Air. Way more than any of these resistive heaters could do for the same electricity consumption.

Ja, dunno ... busy reading again how these stuffs works.. 

[Vetplant]

Ja, dunno ... busy reading again how these stuffs works.. 

http://www.airconco.co.za/Blog/Article-Detail-View/ArticleId/5/Why-you-should-be-using-your-Aircon-as-a-heater

 

 In terms of cost efficiency, Aircons are up to 300% more cost effective than standard electric heaters and up to 1,000% more cost effective than gas or paraffin heaters!

[Karman de Lange]

Do you have double glazed windows? Something I am looking at doing in our bedrooms. 

 

Curtains much cheaper ... That thin white curtain thing you put up for privacy when main curtains are open is amazing to keep room cold/warm. (for life me cannot remember technical name of it)

 

We loose most heat through the walls now.  have 150mm insulation in roof, 50mm below ~20% of floors (solid wood floors with cavity filled)  and just curtains/blinds on all windows.

 

edit:  Have to add ....   Make sure your windows are airtight .. we installed alu with that fluffy seals, made big difference to stop air movement.

Edited May 4, 2021 by Karman de Lange

[Karman de Lange]

http://www.airconco.co.za/Blog/Article-Detail-View/ArticleId/5/Why-you-should-be-using-your-Aircon-as-a-heater

 

 In terms of cost efficiency, Aircons are up to 300% more cost effective than standard electric heaters and up to 1,000% more cost effective than gas or paraffin heaters!

 

you know you just quoted a aircon seller?.......

 

I will forward you article I have.    Air to Air heat pumps are not very efficient, but seems to be better than electric heater if very well installed and used properly.

 

I guess one need to calculate how much aircon captical cost is, vs maintance , and then see if its cheaper in long term than electric coil

Edited May 4, 2021 by Karman de Lange

[Vetplant]

you know you just quoted a aircon seller?.......

 

I will forward you article I have.    Air to Air heat pumps are not very efficient, but seems to be better than electric heater if very well installed and used properly.

 

I guess one need to calculate how much aircon captical cost is, vs maintance , and then see if its cheaper in long term than electric coil

I thought that could come back to haunt me

 

If you don't own an aircon yet, then sure, capital outlay comes into play. But we already own an aircon. People forget that they can use their aircons for heating, and then instead they turn on these panel wall heaters, which is essentially 1/3rd as efficient as an aircon.

 

Air-to-air(which aircons are), are maybe not perfectly ideal heat exchangers, compared to other heat-pumps, but you are so far ahead in the game at 300% efficiency(or higher) that the resistive heating coils don't even come close.

 

Anyways, was just something to consider.

 

Don't let this put you off the coil in the bricks, I would love to hear how this works for you.

[Eddy Gordo]

Curtains much cheaper ... That thin white curtain thing you put up for privacy when main curtains are open is amazing to keep room cold/warm. (for life me cannot remember technical name of it)

 

We loose most heat through the walls now.  have 150mm insulation in roof, 50mm below ~20% of floors (solid wood floors with cavity filled)  and just curtains/blinds on all windows.

 

edit:  Have to add ....   Make sure your windows are airtight .. we installed alu with that fluffy seals, made big difference to stop air movement.

Yes, you talking of the net. Also block out lining helps alot, but doesnt let any light through.

I dont have issues with my floors. I installed that black rubber insulation when the wood was layed. I also did the insulation in the ceiling and that has made a huge difference. I have old wood wind frames. My bedroom and my sons bedroom have the problematic ones and I am gonna replace them soon. Hence why I am looking at double glazed. Not sure of prices, but I am gonna play the friend/family card at the time.

[The Ouzo]

I thought that could come back to haunt me

 

If you don't own an aircon yet, then sure, capital outlay comes into play. But we already own an aircon. People forget that they can use their aircons for heating, and then instead they turn on these panel wall heaters, which is essentially 1/3rd as efficient as an aircon.

 

Air-to-air(which aircons are), are maybe not perfectly ideal heat exchangers, compared to other heat-pumps, but you are so far ahead in the game at 300% efficiency(or higher) that the resistive heating coils don't even come close.

 

Anyways, was just something to consider.

 

Don't let this put you off the coil in the bricks, I would love to hear how this works for you.

I absolutely HATE those wall panel heaters. The only way they work as advertised is if you leave them on the entire day and never ever let a drop of cold air into that room.

Biggest scam under ever.