Anybody else using an electric storage heater?

[arizona98tj]

Yesterday, we just finished the installation of our 2nd electric storage heater. This one went into my wife's new 520 sq ft sewing studio....aka, her she shed.

As wired, the heater runs on off-peak power. When "charging" and using both heating elements, it draws 7.5 KW. The heat generated by the elements is stored in 400 pounds of brick that takes up the majority of the heater's internal space. An onboard controller determines the speed of the blower fan so as to push room air through the bricks and out into the room in order to maintain the desired temperature. An outside temp sensor keeps the controller updated to help it more efficiently determine how much "heat charge" it may need to store during the next cycle. I'm sure the control algorithm is more complex than that but that's basically how it works.

Our electric co-op has two periods each day wherein the storage heater can be charged as needed via the onboard controller. There is also a special relay that is tied into the regular breaker panel. This relay receives control info from the load management center at the co-op which is how the off-peak power is made available. The relay uses a low voltage control circuit tied into the storage heater's controller to complete the control loop.

So last night was the first night of use and the first time after being installed that off-peak power was available. When I got up this morning, a quick trip to the sewing studio showed everything working perfectly. The 2nd photo shows "P 64" which means the off-peak power is not available and the ambient room temp is 64 degrees. The 3rd photo shows "O-31" which means the outside temp was -31F. The 1st photo shows the storage heater as installed in the studio. The 4th photo is of the sewing studio. The 5th photo shows the 400 pounds of bricks before they were installed in the heater.

We'll be putting in a new wood stove in a week or two. When my wife is working in the studio, she'll light a fire in the woodstove. The intended purpose for the storage heater is to maintain a constant temp in the building so that her sewing machines and other items don't experience the winter temp swings that northern Minnesota would otherwise cause.

We have another one of these storage heaters in our 1000 sq ft ICF basement. It keeps the basement very comfortable without really trying all that hard.

During the heating season, we don't pay sales tax on off-peak power and it is about 60% of the cost of normal power. As such, the off-peak rate is it is reasonable and not subject to the fluctuations seen by some that use propane. The co-op has already announced our 2022 electric rates which are the same as the 2021 rates.

We also have a wood stove in the house which we use for heating the main floor. We also have an air-source heat pump, a 15KW plenum heater, and a propane furnace all tied together. We had these installed when we built our house a few years ago. I hope to be cutting firewood for at least another 10 years or more.

A nicety we enjoy that isn't directly related to the storage heater is that should there be a problem or breakdown with the heater, a call to the co-op results in their tech doing the labor for free and we pay for parts if it is out of warranty. That is also true for our other electric heating systems.

So that is the story behind our storage heaters. Anyone else using them?

 

[oosik]

Hmmm - Sounds like an efficient system. There are some terms you use that I'm not familiar with.

# - off-peak power - is this a time when electricity is cheaper

# - sales tax on off-peak power - I've never heard of electric power consumption being taxed

# - charging the storage heater

 

[Jstpssng]

That's interesting, and sounds like it works well for you. Some solar storage systems work on a similar concept, but the heat source is somewhat less predictable... especially on those wintry days when we seem to get snow every three days.

 

[LittleBill21]

can you link whatever this thing is? i have never seen this before

 

[arizona98tj]

# - off-peak power - is this a time when electricity is cheaper

# - sales tax on off-peak power - I've never heard of electric power consumption being taxed

# - charging the storage heater

Yes, off-peak power is cheaper. In our co-op, regular power is about 12 cents a KWH and off-peak is about 7 cents a KWH.

It is a Minnesota tax thing....last time I looked, Minnesota was the 5th highest taxed state in the U.S.

Charging the storage heater.....ie., making power available to it to heat the bricks.

 

[arizona98tj]

can you link whatever this thing is? i have never seen this before

Here you go: https://www.steffes.com/electric-thermal-storage/room-units/

 

[LittleBill21]

thats interesting, what does one of those units cost?

 

[arizona98tj]

thats interesting, what does one of those units cost?

Mine will be around $1500 after the rebate from the co-op. They discount the price more than a for-profit dealer would.

 

[Doofy]

Our Co-Op does nothing for us but raise the rates for every imaginable nuance. We are up to around $0.36 per KWH and rising. Our community is slowly dying, due in part to the exorbitant electrical rates. Businesses have closed and people are leaving. Our local REAA (school district) covered 25,000 square miles and consisted of 9 schools. We are down to 3 schools and 2 of those are becoming iffy. Affordable electrical power is essential for growth of any kind to flourish and I applaud any of you that improve you and your families comfort levels and power use. Wish I had your co-op.

 

[SARG]

Just to mention ......Digital Thermometers with 1,2 or 3 remotes provide the luxury of knowing the "out buildings" are heated. I now have three separate units.

 

[arizona98tj]

Just to mention ......Digital Thermometers with 1,2 or 3 remotes provide the luxury of knowing the "out buildings" are heated. I now have three separate units.

That is a very good idea. I just found one online that has a built-in sensor and 3 external sensors for $65. I could put one in her new building and another in the root cellar.

 

[SARG]

Here's a couple I've purchased for much less and they've worked well for a couple years so far.

https://www.amazon.com/dp/B07D3T8MM4/?coliid=I3QJ576DE6YQ4B&colid=29B4DMFMGZMNA&psc=1&ref_=lv_ov_lig_dp_it

https://www.amazon.com/gp/product/B07HP127L6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[jyoutz]

Yesterday, we just finished the installation of our 2nd electric storage heater. This one went into my wife's new 520 sq ft sewing studio....aka, her she shed.

As wired, the heater runs on off-peak power. When "charging" and using both heating elements, it draws 7.5 KW. The heat generated by the elements is stored in 400 pounds of brick that takes up the majority of the heater's internal space. An onboard controller determines the speed of the blower fan so as to push room air through the bricks and out into the room in order to maintain the desired temperature. An outside temp sensor keeps the controller updated to help it more efficiently determine how much "heat charge" it may need to store during the next cycle. I'm sure the control algorithm is more complex than that but that's basically how it works.

Our electric co-op has two periods each day wherein the storage heater can be charged as needed via the onboard controller. There is also a special relay that is tied into the regular breaker panel. This relay receives control info from the load management center at the co-op which is how the off-peak power is made available. The relay uses a low voltage control circuit tied into the storage heater's controller to complete the control loop.

So last night was the first night of use and the first time after being installed that off-peak power was available. When I got up this morning, a quick trip to the sewing studio showed everything working perfectly. The 2nd photo shows "P 64" which means the off-peak power is not available and the ambient room temp is 64 degrees. The 3rd photo shows "O-31" which means the outside temp was -31F. The 1st photo shows the storage heater as installed in the studio. The 4th photo is of the sewing studio. The 5th photo shows the 400 pounds of bricks before they were installed in the heater.

We'll be putting in a new wood stove in a week or two. When my wife is working in the studio, she'll light a fire in the woodstove. The intended purpose for the storage heater is to maintain a constant temp in the building so that her sewing machines and other items don't experience the winter temp swings that northern Minnesota would otherwise cause.

We have another one of these storage heaters in our 1000 sq ft ICF basement. It keeps the basement very comfortable without really trying all that hard.

During the heating season, we don't pay sales tax on off-peak power and it is about 60% of the cost of normal power. As such, the off-peak rate is it is reasonable and not subject to the fluctuations seen by some that use propane. The co-op has already announced our 2022 electric rates which are the same as the 2021 rates.

We also have a wood stove in the house which we use for heating the main floor. We also have an air-source heat pump, a 15KW plenum heater, and a propane furnace all tied together. We had these installed when we built our house a few years ago. I hope to be cutting firewood for at least another 10 years or more.

A nicety we enjoy that isn't directly related to the storage heater is that should there be a problem or breakdown with the heater, a call to the co-op results in their tech doing the labor for free and we pay for parts if it is out of warranty. That is also true for our other electric heating systems.

So that is the story behind our storage heaters. Anyone else using them?

Sounds like a sweet system. Do you know what the monthly electric bill is for that heater?

 

[arizona98tj]

Sounds like a sweet system. Do you know what the monthly electric bill is for that heater?

As I said, it was just installed a couple of days ago so we're going to have to go a few more weeks before I get a bill. Obviously, it will depend on what we set the temperature to and also how cold it is outside.

If others wish to consider it as a heating option, they will need to take into consideration how energy efficient their building is. My wife's studio doesn't have the flooring installed yet, that is how new it is. It is very well insulated too with 6" walls, 1" hard foam between the OSB walls and the wood siding, with about 16" of blown-in insulation in the attic. The floating slab has 1" foam under it and 1.5" foam around it. Lastly, the windows are quite good and have excellent solar gain for the larger windows via their south-facing placement.

That all being said, I'm guessing my heating bill will rise about $50~$60 a month during the coldest winter months....but that is just an educated guess. I won't know until later in February. Also, the building will have a nice wood stove in it so the days my wife is working in her studio, she'll have a fire going which will greatly reduce what the storage heater needs to supply to maintain the desired temp. In fact, with it's thermostat set to a lesser room temp than what the wood stove is maintaining,the storage heater's variable speed blower will shut down and conserve the stored heat in the bricks.

I know what the bill is for the identical storage heater I have in my basement, but comparing the two would be apples and oranges since the basement is twice the size of this new building, and....well, it's an ICF basement vs. an above-ground building. Regardless, I just looked at last year's June and January electric bills for the house....there was a difference of $46. The major difference for the winter months is that I run the storage heater in the basement and we use more lights because of the much shorter days. Also remember that the house (less the basement) is heated by wood all winter. Things like hot water, drying clothes, TV, kitchen appliances, etc. would pretty much be a constant regardless of which month you look at. And another data point....right now, my root cellar, which is an unheated 10'x12' section of ICF basement that adjoins the rest of the basement via an insulated door, is sitting at 36 degrees F. Based on that, I would say that the rest of my basement would also be at that temp if I were to turn off the storage heater. That gives you somewhat of an idea of how well that storage heater does in the basement.