Is Steam Inefficient?

Gordy

Hot Water is more flexible as in emitter types, and water temps to drive those different types of emitters. Alternative energy to drive the heat source. Mainly solar being more feasible.

Charlie from wmass

Electricity will take over in a couple decades. Fossil fuel heating will be as extinct in 50 years as it's source material.

Jamie Hall

Charlie from wmass said:

Electricity will take over in a couple decades. Fossil fuel heating will be as extinct in 50 years as it's source material.

Now you've been listening to the "Green New Deal"! Maybe -- but it's going to take a pretty terrific investment in the grid, never mind the power generation and storage... a steam electric boiler to replace Cedric (they exist) would draw 120 KW...

Charlie from wmass

@Jamie Hall eco rad would simply electrify each radiator for you like in Quebec. No boiler and room by room temp control PC field out back and you should be all set

Voyager

Charlie from wmass said:

Electricity will take over in a couple decades. Fossil fuel heating will be as extinct in 50 years as it's source material.

Well, if we build enough new nuclear plants...

Charlie from wmass

@Voyager nice big fusion generator we circle once a year will provide most of what we need. Battery tech will even out the flow.

Charlie from wmass

Boy I can get off topic. Steam can be efficient enough to negate any return on investment versus conversion to hot water or forced air. The Sticky Wicket is having a competent contractor work on your system without acting as if they are an artisan.

Jamie Hall

Charlie from wmass said:

@Jamie Hall eco rad would simply electrify each radiator for you like in Quebec. No boiler and room by room temp control PC field out back and you should be all set

I don't own enough land to provide the power required ... 54 acres more or less.

Charlie from wmass

Current technology is 453 kw per acre

Jamie Hall

Yeah. I misplaced a decimal point. I'd need 5 and half acres. Still, that's all of my tillable land...

Voyager

Charlie from wmass said:

@Voyager nice big fusion generator we circle once a year will provide most of what we need. Battery tech will even out the flow.

Have you calculated how much battery storage you would need to heat a house overnight on a 14 hour long winter night in the northeast?

ChrisJ

Voyager said:

Charlie from wmass said:

@Voyager nice big fusion generator we circle once a year will provide most of what we need. Battery tech will even out the flow.

Have you calculated how much battery storage you would need to heat a house overnight on a 14 hour long winter night in the northeast?

Doesn't that depend on the house?

A 2000 sqft house with 6" walls filled with spray foam, very few, but high quality windows and R38 or better in the attic I'm betting can get by with very little.

Can someone do a heatloss on that real quick?

Jamie Hall

It does depend on the house, of course -- and also a lot of assumptions about the weather, assuming one is talking about local (on-site) storage. Also, as always, what do you want? Do you want to be able (talking New England here) to ride out a nor'easter? Then you're looking at 3 days (72 hours) of no sun at all, near design temperatures, and wind. That's a lot of battery, even for a small house. For Cedric, though, it would be almost 10 megawatt hours. Scribbling on the back of the envelope without my coffee yet...

Voyager

ChrisJ said:

Doesn't that depend on the house?

A 2000 sqft house with 6" walls filled with spray foam, very few, but high quality windows and R38 or better in the attic I'm betting can get by with very little.

Can someone do a heatloss on that real quick?

Of course. We are talking a typical steam heated house here, correct? I am guessing it doesn’t have R38 anywhere. LOL.

You give me the heat loss you think is reasonable and I will do the electricall calculations. Good practice for this retired EE. 😁

Jamie Hall

While you're at it on @ChrisJ 's house, @Voyager , you can double check my calculations -- I'm figuring on a 120 KW input electric steam boiler, and 3 days (72 hours) without power (we've had worse) and no sun and wind and near design day (we've had worse than that, too...).

The questions and discussion isn't irrelevant, though it is political -- there are some very high profile politicians currently calling for everything in the US to go to renewable electric in the next 11 years...

ChrisJ

I can tell you exactly what my heatloss is, but I thought we were going with a theoretical future house?


My actual heatloss at -8F was 72,000 btu/h input I believe, going from memory. That's as per what the Ecosteam required to maintain temperature. It could've been 71,849 or 72,100, but it was approximately 72K. That's for a 1600sqft house built in the 1860s. It's pre-steam in my opinion as it was originally heated by coal stoves.

Voyager

We can go with any conditions you like, but if the comparison is to a steam boiler, then it needs to be realistic. If you have a house that is super insulated and super tight and loses only 20,000 BTUH, can you even get a steam boiler small enough to make such an installation practical?

ChrisJ

Voyager said:

We can go with any conditions you like, but if the comparison is to a steam boiler, then it needs to be realistic. If you have a house that is super insulated and super tight and loses only 20,000 BTUH, can you even get a steam boiler small enough to make such an installation practical?

Oddly enough I thought we were now talking about electric heat and batteries from solar.........

Jamie Hall

I just want to know if my calculations are in the ballpark... the places I care for are all steam, and being historic structures/museums the odds on converting to anything else are between slim and none. So if I have to go with an electric steam boiler, what kind of battery backup would I need to take the place of the oil tank?

Charlie from wmass

But I am not proposing electric steam boilers. I am saying direct heating of each radiator with electric elements in a heat transfer fluid.

ChrisJ

Charlie from wmass said:

But I am not proposing electric steam boilers. I am saying direct heating of each radiator with electric elements in a heat transfer fluid.

Essentially, a $60 oil filled radiator.

Gsmith

on a strictly mathematical basis using @ChrisJ's 72,000 btu/hr input at say (arbitrarily) 85% boiler efficiency yields 61,200 btu/hr heat released to the conditioned space of the house. At 1 kW=3,412 btu/hr that heat supply needs 17.9 kW at 100% electric wire to heat efficiency, times 24 hours times 3 days, for @Jamie Hall's nor'easter coverage, means if I did the multiplication right, an energy storage battery of 1,288 kw-hr. And, if it was stored in conventional 12 volt auto batteries, that 1,288 kW would be 1,288 x 1,000 watt-hours / 12 volts = 107,000 amp-hours. or about 180 12-volt 600 amp-hour auto batteries if you could discharge them from completely full to completely empty, which probably won't work but once, so more batteries than that are needed, but you have, I think, the order of magnitude.... several hundred conventional 12-volt batteries (ignoring losses in converting to AC current). Didn't double check the math, but perhaps some one could.

ChrisJ

Gary Smith said:

on a strictly mathematical basis using @ChrisJ's 72,000 btu/hr input at say (arbitrarily) 85% boiler efficiency yields 61,200 btu/hr heat released to the conditioned space of the house. At 1 kW=3,412 btu/hr that heat supply needs 17.9 kW at 100% electric wire to heat efficiency, times 24 hours times 3 days, for @Jamie Hall's nor'easter coverage, means if I did the multiplication right, an energy storage battery of 1,288 kw-hr. And, if it was stored in conventional 12 volt auto batteries, that 1,288 kW would be 1,288 x 1,000 watt-hours / 12 volts = 107,000 amp-hours. or about 180 12-volt 600 amp-hour auto batteries if you could discharge them from completely full to completely empty, which probably won't work but once, so more batteries than that are needed, but you have, I think, the order of magnitude.... several hundred conventional 12-volt batteries (ignoring losses in converting to AC current). Didn't double check the math, but perhaps some one could.

Actually I made a typo.....
That was output btu/h not input.

Charlie from wmass

Does anyone have access to the Tesla battery information? Also effective efficiency would not be that low as no combustion is occurring. Also no loss to a chimney.

Charlie from wmass

www.chromalox.com/en/catalog/industrial-heaters-and-systems/electric-steam-boilers/electric-steam-and-hot-water-boilers?application=com

Gsmith

@chrisj: no worries, if i calculated correctly the difference is only 15%, still order of magnitude.

Jamie Hall

Yeah -- the smallest of the CHS series would work. Now to get a new line from the road and building switchgear to handle the 600 amperes needed...

Voyager

Gary’s calculations look OK to me at first blush. Using Jamie’s 3 day armageddon scenario, you would need 1288 kWh/13.5 kWh = 95.4 Tesla Powerwall storage units.

According to the web site below, two powerwall units plus associated hardware are $14,500. So, the 96 units needed would only cost $696,000. Assuming, as Gary said, that my calculations are correct.

The reality is that cost-effective electrical energy storage is still not available. Maybe it will be in 10 years or 50 as postulated earlier, but I doubt it. I think modular nukes are the long range answer to baseload electric generation, but the political climate is currently too much against nuclear power. Although, Bill Gates did come out in support of it recently...

https://www.tesla.com/powerwall

SuperJ

If electric heat and battery storage are being considered together, than some sort of heat pump should be part of the mix. Conservatively you can cut your kwh by a factor of at least 3 with a heat pump versus electric resistance heating.

The exception might be dumping extra PV capacity to a hot water tank with a DC heater.

Gsmith

yes, but 200 or 300 auto batteries at $100 each would only be about $20,000 to $30,000. Isn't that why fuel oil currently has a big advantage in energy density, and natural gas provided by a utilty system has good reliability even when the power lines are down. MIght be a while before electricity takes over, probably needs a technology breakthrough.

ChrisJ

Since it was brought up, you could in theory build heat pumps using water as refrigerant. Which, in that case would be considered steam heat, technically.............No?

And those heat pumps would pretty much destroy any equivalent electric hot water system in regards to efficiency. No?

Steve Minnich

In my perfect home, I'd have at least two heating systems.

One with low temperature radiant floors paired with a modulating condensing boiler.

The other, a new steam system.

As many bell and whistles as I could possibly add to each.

It would be like a laboratory environment where I could compile solid data comparing comfort and efficiency in the same envelope.

No. My wife wouldn't mind.

Voyager

My perfect house would have a high efficiently water heater that would be used to warm the basement slab through pex and be used under the floor of the bathrooms in the upper stories. This would be used mainly to have warm floors.

I would then have a well designed forced air system for fast response to outside temp changes, for humidification, for high efficiency air filtering, for fresh air via HRV and for AC.

I have this now except for whole house humiliation and inslab and underfloor hydronic. If I had those, it would be near perfection.

Intplm.

I had a fortunate up bringing. Steam heat in my house as a child. I still miss it to this day.
An old one pipe steam system. A steam boiler from Sears & Roebock no less .Was great to hear each and every one of those radiators come up to temp. with the quiet sound of the vents shutting off one by one in each room at each radiator.
The first steam boiler I ever replaced was that boiler with a new steam boiler at the age of 17.
Folks who have had it wish they still did. Those who have it and it's correct, do not want to change it.
Steam is efficient.
Thanks @RayWohlfarth for the topic. Keep it coming.