Electric radiant floor

Gta

8024 kw used in a 30 day period 😔😔 this house is going to break me . At .89 c a kw my last bill is 800 , all in . I’m heating 2800 of living area and 1500 garage . The 23 kw boiler runs almost constantly, I’ve had multiple people look at this thing , now looking at a gas stove to mostly abandon this stupid radiant system , sigh I wish I had a furnace, but that’s not possible now as the entire thing is icf and the floors are stone/concrete 

Gta

Sadly this is the most inefficient giant mistake I’ve made , I’m at my wits end selling and moving Is now something we r looking at. 

Gta

Can a propane boiler be vented down ?
ive thought of changing it but the entire stupid house is concrete so I can’t get a vent out 

Jamie Hall

There are a few areas of the country and Canada where electric heat is competitive. Doesn't sound as though you are in one. Generally speaking, venting can go horizontal (more or less) or up -- but down may be quite problematic. Can you vent straight up through the roof somewhere? That would be the simplest.

However, that's not the end of it. With a boiler, you also have to put the boiler somewhere, and run the piping and radiators -- and that could get interesting in a house much of which is concrete.

One option, though, which sounds slightly insane but may not be is individual propane cabinet type heaters. They can vent straight through the wall behind them, and the opening required is not that large -- a core drill could do it quite easily, even through reinforced concrete. Depending on the heating load in the various rooms, and how they are arranged, you might find that a practical solution.

Steamhead

@Gta , where are you located?

Gta

Manitoba...

Gta

Sadly I can’t go up , radiant concrete floor above ... we’re I live there are no radiant experts, 

Zman

Why can't you core through the concrete radiant floor above? If you are just concerned about the tubes, they are pretty easy to avoid.
How are your slabs insulated? How is the boiler being controlled?
Your costs should not be that high, your electricity per KWH is pretty reasonable. Are you getting dinged with excessive demand charges? If you divide the total bill by consumed KWH, what is the gross cost?
What are your alternative fuels and what do they cost?

Gta

Slab is insulated well .. it’s controlled by rehau digital t stats .. 3 zones and 3 separate t stats , maybe I should try s nest or something. I hate these things.. they turn on when the air temp drops .1-.2 c

Jamie Hall

One other thing about radiant floors -- they respond very slowly. Therefore, you should strive to keep the house temperature as steady as possible. In particular, no setbacks. Set it and forget it.

Zman

Gta said:

Slab is insulated well .. it’s controlled by rehau digital t stats .. 3 zones and 3 separate t stats , maybe I should try s nest or something. I hate these things.. they turn on when the air temp drops .1-.2 c

I was not referring to the t-stats and certainly would not recommend a Nest for this application.
What is determining the the water temp leaving the boiler? Is outdoor temp being considered (outdoor reset)?
Sending water that is too hot to the floor can create a flywheel effect which wastes energy. Some utilities have a low base rate but penalize users for demand spikes during peak times. From the information you are providing, your monthly bills don't seem right.

More pictures of the boiler room would help as would copies of your electric bill...

Gta

Sure I can get pics

Gta

Temp set at 120f ang yes I do have a outdoor reset

Gta

Pumps are set to speed 1 and flows set to .5 gpm aprox ... 

Zman

That is a puzzler. Did you look for a demand charge on electric bill? Are the room temperatures stable with no big overshoots? Radiant should not use more energy than other heating system when properly installed

Gta

No over shoots ... yeah it’s heating 2000 ft main level all tile , 800 bonus room.. wood covered, and s 1500 ft attached garage at 12-14 c . I still think it should be much better than it is , I’m planning on installing a gas burning heat stove to try to save 

Jamie Hall

Maybe not. You need to compare the cost of energy from the electric vs the gas -- BTU for BTU -- before you do anything.

Robert_25

Gta said:

No over shoots ... yeah it’s heating 2000 ft main level all tile , 800 bonus room.. wood covered, and s 1500 ft attached garage at 12-14 c . I still think it should be much better than it is , I’m planning on installing a gas burning heat stove to try to save 

You are heating a large home in a cold climate with a somewhat expensive fuel source. I am not sure what you were expecting to pay, but your numbers don't seem out of line to me. Especially if the house has a lot of glass in it and you are keeping it at a cozy temperature. The boiler will run almost all the time due to way it operates, more or less elements will turn on depending on the load.

Mid January to mid February is the coldest time of the year, and your house averaged 8-9 btu's per sq foot of living space (depends how much of your electric is used for things other than space heating). For comparison, my house is a similar size, and located about an hour South of Montreal - during the same time period my house averaged 11 btu's per sq foot of living space.

You have two choices. Reduce the heat load of the house, or find a cheaper fuel source.

Jamie Hall said:

Maybe not. You need to compare the cost of energy from the electric vs the gas -- BTU for BTU -- before you do anything.

Good advice from Jamie - before you make any changes see what your local pricing is for other fuel sources.

Gta

Hi , thx for the reply yeah lots of glass , big windows, glass doors...  I can get propane delivered to me for .60 c s litre . 

It’d at a reduced price as I run a grain farm and use ag propane that is currently priced at this . But I am not sure how long that price will last as residential propane is .85-90 locally . 

If anything the heat stove would add a nice look and can use it in the -40 weather we had

Robert_25

At $0.60 per liter for propane that is even more expensive than your electric on a $/btu basis. With that said, if the propane stove allows you to keep one room warm and reduce the temperature of other parts of the house, it might help with the overall bill.

If you can find a gas stove that works without electrical power, that would certainly be a benefit in the event of a power outage. Even if it does require a small amount of electrical power, you could use it with a small generator - which is not the case for your electric boiler.

TAG

In the states using gallons -- the simple formula is 27 x electric rate. My rates always pushed .20 at my weekend place in PA for years so I'm at $5.40 gallon. Now -- my rates have dropped at bit. Even at .18 ...I'm at $4.86 propane.

My three fills this winter have been $1.59 (800g) -- $1.69 (600g) two weeks ago $2.02 (500g). 5000sf house w/ 95% and 1600sf outbuilding at 80%.

I'm under the typical target of .10 for electric KW -- that's when most say to switch. Heat pumps have changed this as now you can get 3 COP when cold. These are rough numbers -- propane can jump around .. and you are not getting 100% out of the fuel

NG would be a fraction of the cost .... My suburban house in NJ is about the same size (no outbuilding) .. 1/4 to 1/3 the cost with NG

Maybe add a mini-split in the biggest area user

Gta

Update: I have decided to upgrade my electric lion boiler from 23 kw to 28 kw .

I have always struggled to get the water temp to 120-130 f leaving the boiler .. I honestly think this lil guy is just working too hard to heat 2800 sq ft of living area and 1500 of garage in our extreme climate.  I will let you know if it saved me energy. It’s a minimal cost to try and at this point it looks like a option I’m willing to try . 

hot_rod

Are there check valves in all those circulators? You could be moving heat around zones when they are not calling with that piping. Put your hand a few feet away from the pumps and see if the piping is warm when the pump is not running. Over shooting the thermostat setting would be another indication of ghost flow.

What temperature are you keeping the garage. If it has overhead doors, that can be a big load and $$ space to keep warm.

Gta

Yes , check valves in place ... no ghost flow , yes the garage has big overhead doors one is 18 ft and the other is small single car 8 or 9 ft . I keep garage at bout 12-14 c as it’s finished completely same as house . 

hot_rod

well, you are heating 4300 sq ft of home and garage... so. Do you have a heat load calc for the home, room by room/ The 23K boiler will get you 78,000BTU/hr. 4300/78,000= 18 BTU/ft. A reasonable number if it is well constructed and tightly insulated.

What supply water temperature is needed? If you can cover the load with 120F or less on design day, an air to water heat pump could get you around a 2 COP at 0° outdoor. Essentially dropping you bill by 1/2.

If you plan on staying and plan on using electricity it may be an option to consider. Plenty of Canadian A2WHP brands that specialize in cold climate.

Nordic is a brand out of Petitcodiac, NB, they know your climate and challenges. nordicghp.com
https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

Gta

Yeah it’s all icf construction.. no basement just a crawl space ... it’s ok I guess , the thing just runs a lot ... I’m going to try a bigger boiler . I’m hoping that hotter inlet water temps will keep the house warmer and keep the boiler off for longer 🤞🤞🤞

bburd

If you keep the house at the same temperature, a bigger electric boiler running less time will use the same amount of power as what you have now. All electric resistance boilers are 100% efficient, and there is no getting around the laws of physics.

The only exception I can think of is if the slab is not insulated, the subslab conditions are unusual, and you need higher water temperatures to get the heat into the house.

psb75

There is a company in Manitoba that makes a cold climate A2W heat pump. Its name is Arctic. Those folks must know something about radiant heating. I have purchased and installed several and they work fine in Vermont--in the right application. This was over a year ago--before tariffs and Covid. Now they are not so easy to get or as affordable in the U.S.

ethicalpaul

Is a ground-source water-to-water heat pump possible?

Gta

Hi yes I’m aware of the artic heat pumps . And yes geo is available but the cost of those at the moment to me is just not something I can do .

hot_rod

it's all in the number crunching. IF you could drop that $800 bill to 1/2, what would the payback be? And resale value.

The home (building) dictates your energy bill, really no other way to put it.
Lower the load, reduce the energy cost, use the energy as efficiently as possible, best any of us can offer.

What is the R-value of all your glass? I doubt it is anywhere close to you ICF value
Insulated window coverings could maybe help lower that large "loss" area. Helps in the cooling season also.

Gta

Yes thx .. I do have a almost entire wall of glass .. it’s a triple pane gas filled but yes I know it’s a huge heat loss area , I do have blinds that are insulating ... trouble is when they r closed I get lots and lots of ice build up ... for now I’m going to just try the bigger boiler , I’ve s as I’ve always thought and been told it’s undersized for s home this big , other than that it is what it is and it takes so many btu to warm that area

hot_rod

Unless the home is cold or does not keep up to the thermostat on your coldest day, the only thing upsizing the boiler will do it take more $$ out of your wallet.

OR that money could go towards your electric bill

If you must, check with the boiler manufacturer first, some times you can just replace the elements in a boiler to upgrade to a higher output, no need to start over with a new one.

Gta

That’s exactly what we r doing ... I have 2 unused ports that will be outfitted with elements... it’s a easy change that I can try

hot_rod

Gta said:

That’s exactly what we r doing ... I have 2 unused ports that will be outfitted with elements... it’s a easy change that I can try

As long as the circuit suppling it, wire and breaker size, can handle the extra current draw you will be adding.
5KW on a 240V circuit will pull a bit over 20 amp, so you need an additional 30A capacity in the service.

Gta

Yes  it’s a wire change.. my currently one is not big enough to carry the additional load.      




   

Gta

Yes  it’s a wire change.. my currently one is not big enough to carry the additional load.      




   

Gta

Here is the current and not big enough supply wire

skipt

psb75 said:

There is a company in Manitoba that makes a cold climate A2W heat pump. Its name is Arctic. Those folks must know something about radiant heating. I have purchased and installed several and they work fine in Vermont--in the right application. This was over a year ago--before tariffs and Covid. Now they are not so easy to get or as affordable in the U.S.

Hi @psb75 can you comment more on your experience with Arctic A2W heat pumps? I am looking at the 050ZA for my new house as its specs seem to fit well, and it seems quite a bit cheaper than a similar-spec SpacePak. The names Arctic, Nordic, SpacePak are are new to me so it feels like a crap-shoot when it comes to reliability, longevity, service. In your experience, what do you see as the positive and negative aspects of the Arctic HP's? MANY thanks for your comments.

And sorry to drag up an old thread... especially one titled electric radiant!

psb75

The only Arctic unit I have installed was carefully chosen to fit the newly constructed small residence (1500 sqft.) The building is tight and well insulated with an ERV system. Ground floor is a properly done radiant slab. The Arctic has a 30 gal. buffer tank and a Rinnai 60kw LP boiler for back-up. This system includes a 40 gal. indirect DHW tank. It is the smallest system that Arctic sells. It was installed 6 or 7 years ago. It is working very well. The hydronic system has 40% glycol in it. It is in north central Vermont.