Total cost of ownership

DanHolohan

Let's say you have a client who wants to build a large house. He asks you to design a heating system that would be very reliable (consider storms, power outages, and fuel availability) and have the lowest possible total cost of ownership over the next 50 years. What would you design?

Tom_133

Dan, are we handcuffed by upfront costs? Do we factor current incentives? Location of said house, changing possible heat losses and design of equipment? I have more but I assume you are just looking for best overall?

DanHolohan

Thanks, @Tom_133. No handcuffs. Consider cost of equipment and installation, fuel used over 50 years, and all maintenance. What sort of system would give your client the most reliability and economy over the next half-century?

RayWohlfarth

If I were designing it and didnt have to worry about decarbonization and fossil fuels, I would suggest a radiant heating system with a gas fired boiler. According to ASHRAE, the life expectancy for a boiler is 25-30 years.
If the power availability is questionable, I may choose a standard efficiency boiler and would only need 24 volts for the gas valve and power for the circulator. It will last forever
When I was first married with kids, we had a one pipe steam steam system with a power pile pilot. The power would often go out in the area and we always had heat because the system needed no power. The neighbors found out about this and would send their kids over to our place because they knew we were always warm
Respectfully
Ray

DanHolohan

I'm asking because a friend sent this and it made me think:

I have done a lot o designs and done a ton of service
and if I was building a mansion it would install a single pipe steam system
with an old fashioned millivolt gas valve (i don't even want the electric co involved)
and a mechanical float driven water feeder with a tank on the upper floor to with reverse osmosis and deionized water for gravity feeding

the header would of course be a drop header and then go all the way to the roof's ridgeline and feed across and downward so that steam and condensate travel in the same direction - talk about an "a" dimension, cant beat that!!!

my challenge is this: the 50years TCO(Total Cost of Ownership) that is install, fuel, maintenance after 50years, that system will have a TCO way less than anything else including radiant with geothermal heat pumps!!!

even stupid old fashioned water heaters are better than the new fangled tankless - i fix them also - i my house I have two high recovery 50's that's 130000btu in the water, i can stand in the shower all day, and i have redundancy - because water heaters seem to know exactly when the holidays are and promptly fail

its not just the TCO it's also the cost of aggravation - with a my system you can go on vacation and know that the house won't freeze and bust even if there is a power outage - you can't put a price on that kind peace of mind

i do lots of service and if you have to change a combustion fan in a modcon boiler - the gas savings of ten years is lost, kinda stupid... that's why my challenge is 50yr TCO

newtonkid88

Hard to predict the cost of fuels over a 50 year span. Right now, it can cost $1,000 to fill up a 275 gal oil tank.

In the history of ever, has electric element heat ever been cheaper than a fossil fuel heat?

How about a heat pump inverter type system like Mitsubishi? You get AC with that too

JakeCK

TCO would be largely dependent on how tight and efficient the house is, and not the heating system imo. Build a passive house where you can heat it with a candle at design and tell me the TCO. If I'm building a house from the ground up and budget isn't a concern that is the route I'm going. High upfront costs but energy and maintenance costs would never be a concern again. 

Just have to manage that pesky water vapor and condensation. 

Steamhead

ISTR we had a similar discussion in HH.com's early days, but it probably got lost in a software change.

It involved planning a heating system when electricity and maybe gas and oil supply were unreliable. The consensus was steam, since most of the system drains dry when the system shuts off. This would sharply limit if not eliminate freezing damage to the system.

If I were doing this, I'd build a Tudor system. Aside from the boiler itself and its controls, in a small house the system would only have two moving parts- air vents on the steam main and dry return.

DanHolohan said:

I'm asking because a friend sent this and it made me think:

I have done a lot o designs and done a ton of service
and if I was building a mansion it would install a single pipe steam system
with an old fashioned millivolt gas valve (i don't even want the electric co involved)
and a mechanical float driven water feeder with a tank on the upper floor to with reverse osmosis and deionized water for gravity feeding

the header would of course be a drop header and then go all the way to the roof's ridgeline and feed across and downward so that steam and condensate travel in the same direction - talk about an "a" dimension, cant beat that!!!

my challenge is this: the 50years TCO(Total Cost of Ownership) that is install, fuel, maintenance after 50years, that system will have a TCO way less than anything else including radiant with geothermal heat pumps!!!

even stupid old fashioned water heaters are better than the new fangled tankless - i fix them also - i my house I have two high recovery 50's that's 130000btu in the water, i can stand in the shower all day, and i have redundancy - because water heaters seem to know exactly when the holidays are and promptly fail

its not just the TCO it's also the cost of aggravation - with a my system you can go on vacation and know that the house won't freeze and bust even if there is a power outage - you can't put a price on that kind peace of mind

i do lots of service and if you have to change a combustion fan in a modcon boiler - the gas savings of ten years is lost, kinda stupid... that's why my challenge is 50yr TCO

STEVEusaPA

I can do it for free...if I built the mansion somewhere tropical.
Who doesn't love the steam idea? As long as they can still get a gas hook up. But B100 could also be better than natural gas, but no millivolt, so you'd need backup power for an outage.

ratio

I've been thinking that a two pipe naturally-induced vacuum steamer with a millivolt gas valve would be fun to have. Especially now that I know that someone else will end up with my electricity of we run short.

Jamie Hall

Is this a build from scratch house? Then I'd start out right at square one to make as much use of passive solar techniques as possible. Could I make it 100% passive? Very likely not. By which I mean that it is almost always (not quite always) easier to set up the interior spaces and heat store to use a single low power circulating fan. But that's where I'd start.

Can this be done? Yes, at least in New England (there are at least half a dozen such I've been involved with, and I know of a number of others). Depending on how fanatical one is -- and how good one's builder is -- one can get to essentially zero fuel cost. The first capital cost is greater than "regular" construction; experience suggests around 10% premium.

JUGHNE

I agree with Jamie on the passive solar heated house.

But also point out passive cooling, that is not needing the AC until we hit the 90's.

Simply having south windows and doors with corresponding north openings allows the wind to pass thru, (something we are seldom short of in Nebr.)

Of course you need some land to do this, we have a 2 acre lot in town and get plenty of breeze passing thru the house.

gerry gill

I think I would do a millivolt gravity hot water job.

GW

If Client wants AC, we’re probably talking Geothermal. If he she wants a nice new big house, I’m sure s-he wants to be cool too

Larry Weingarten

Hi, I agree with Jamie and JakeCK; start with a good shell. I like SIPS. Energy prices don't go down, so plan on the shell being effective even towards the end of its life. I built my place with 8" walls, 10" floors and 12" roof, all SIPS, and people told me I was crazy. Not so much these days. My energy use is about 10% of normal and construction cost me less than half the going rate in dollars per square foot at the time. I faced the house North even though I'm in a mild heating climate, Keeping things simple helps make them durable, so I don't have a lot of high tech or complex equipment in the house. I designed it for minimal upkeep and very low energy needs. Anyway, those are some basic guidelines I'd work with for my hypothetical client.

Yours, Larry

EdTheHeaterMan

There is a house in the New Jersey Pinelands that has a well that reaches a methane pocket. There was about 2"WC pressure coming from that well over 80 years ago. I think it is down to about 1.2" WC now. I wonder what that gas pressure will be down to in 50 years? I know they use it for cooking and heating. There is your lowest cost of ownership. Drilling for water and get Natural gas by accident.

That and a millivolt gas valve on a gravity water or @DanHolohan's steam system might be all you need for the next 50 years. Just keep enlarging the gas burner orifices every 10 years as needed!

Hot_water_fan

A huge part of TCO is resale because plans change. Insulation, air sealing with a hybrid furnace/air source heat pump gets the AC future buyers want with the fuel flexibility. Tight and insulated should let you ride out short outages, while the furnace can run with minor power. 

ChrisJ

Very reliable and able to run easily during storms and power outages.

Either steam or gravity hot water with cast iron radiators and a simple atmospheric cast iron boiler.

Millivolt would be preferred and is technically possible if doing your own work. If someone made a DC gas valve both systems could easily be run for weeks on battery power. Worse case. both can be run by battery using an inverter. Probably depends on your location too though, can you use LPG in areas that see -40F?

On a similar note I'd love to know what the original cost of the 80% 120K input Mueller Climatrol furnace that was in the house I grew up in. Even though I can't stand forced air, that furnace ran basically untouched other than filters for 45 years and even then just needed a new gas valve. Something tells me that blower and cast iron heat exchanger wasn't exactly cheap. If it was affordable, that might be the bottom of total cost of ownership.

george_42

I did this at my house 4 years ago. Foan insulation with dround sourse geothermal . 3500 sq ft home takes about 80 dollars a month with 11 cents per kw

ChrisJ

george_42 said:

I did this at my house 4 years ago. Foan insulation with dround sourse geothermal . 3500 sq ft home takes about 80 dollars a month with 11 cents per kw

Where are you located and what's the design temp?

JUGHNE

ChrisJ, FWIW, I did see some gas valves rated for 24 VAC/12 VDC on furnaces from 50's-early 60's.
Standing pilot with standard thermcouple.

I believe the intent of these was battery operation for power failure. Burner could cycle on high limit.
Blower door removal could permit some gravity air flow......not safe to do.....

And LPG is in use in the Dakotas and Minnesota.
Often the tank is buried to keep the it slightly warmer than ambient.

ChrisJ

JUGHNE said:

ChrisJ, FWIW, I did see some gas valves rated for 24 VAC/12 VDC on furnaces from 50's-early 60's.
Standing pilot with standard thermcouple.

I believe the intent of these was battery operation for power failure. Burner could cycle on high limit.
Blower door removal could permit some gravity air flow......not safe to do.....

And LPG is in use in the Dakotas and Minnesota.
Often the tank is buried to keep the it slightly warmer than ambient.

I was thinking battery operation with steam or gravity HW obviously not forced hot air.
I guess you could also do it with gravity air (Is that what the octopus duct systems are called?) if there's any of them left.

george_42

I am in central pa with geothermal and keep house in the 60`s summer and 70`s winter

hot_rod

Would you design just a heating system in this day and age? Or make the buyer aware of the bigger picture, a comfort system. A system that heats, cools, adds or removes humidity and filters the air.

 It the home is tightly constructed, then ventilation recovery would also be part of the system. A system that follows ASHRAE guidelines perhaps.




Or just a simple wood stove centrally located for the other end of the spectrum😉

TAG

Having built and rebuilt a number of houses and odd building I don't see how anything can match the cost of a duel fuel ducted system with modern construction.

Insulate properly w/ good windows. Add zoning -- I always zone and the new VS equipment is perfect for zoning.

My last odd project was a church and I had some challenges with ductwork -- since I planned on owning it for a long time and only had one shot to get it all right -- I did full radiant as well as ducted. The radiant was about 3x the cost of the ducted. That blew the total cost of ownership.

I'm in the mid-atlantic. My beach house is on the water with a lot of glass and my primary is an historic stone structure from the 1870's that I rebuilt and updated w/ foam and good windows. Both get close to having too low a heat load ...

People did hot water for comfort in big old leaky houses

ChrisJ

hot_rod said:

Would you design just a heating system in this day and age? Or make the buyer aware of the bigger picture, a comfort system. A system that heats, cools, adds or removes humidity and filters the air.

 It the home is tightly constructed, then ventilation recovery would also be part of the system. A system that follows ASHRAE guidelines perhaps.




Or just a simple wood stove centrally located for the other end of the spectrum😉

Well.
If I was building a house for my self, yes, I would do cast iron radiators and probably steam and then a ducted system for cooling and a dehumidification. Filtering the air doesn't seem to do anything really as far as dust removal at least that's been my experience.



However,
Dan's question was "He asks you to design a heating system"
So what I would do, or anyone else here for that matter isn't relevant.

I remember some school tests where that would've been a fail because you didn't follow instructions.

But the wood stove......
Build a two story house with a large open center and a 2nd floor that wraps around the center over looking everything and put a wood / coal stove in the center. That's probably by far the cheapest and most reliable and most certainly works during storms. I think you win on that one.

Hot_water_fan

Having built and rebuilt a number of houses and odd building I don't see how anything can match the cost of a duel fuel ducted system with modern construction. 

Agreed - and the market reflects this. If steam/geothermal/passive solar/solar thermal/hamsters/whatever added value, new homes would have it. Since the vast majority do not, we can safely assume on day one the additional costs will not be recouped at sale. That really sinks TCO! 

hot_rod

ChrisJ said:

hot_rod said:

Would you design just a heating system in this day and age? Or make the buyer aware of the bigger picture, a comfort system. A system that heats, cools, adds or removes humidity and filters the air.

 It the home is tightly constructed, then ventilation recovery would also be part of the system. A system that follows ASHRAE guidelines perhaps.




Or just a simple wood stove centrally located for the other end of the spectrum😉

Well.
If I was building a house for my self, yes, I would do cast iron radiators and probably steam and then a ducted system for cooling and a dehumidification. Filtering the air doesn't seem to do anything really as far as dust removal at least that's been my experience.



However,
Dan's question was "He asks you to design a heating system"
So what I would do, or anyone else here for that matter isn't relevant.

I remember some school tests where that would've been a fail because you didn't follow instructions.

But the wood stove......
Build a two story house with a large open center and a 2nd floor that wraps around the center over looking everything and put a wood / coal stove in the center. That's probably by far the cheapest and most reliable and most certainly works during storms. I think you win on that one.

I'd say no thanks, especially not knowing where the home was to be built

leonz

If I were to do this, I would have a top fed gravity hot water system with an open to air steel expansion tank and cast iron radiators.
The boiler would be plugged into a 110-volt electrical outlet and the boiler could be powered by a small generator if there was a black out and natural gas, propane, oil or stoker coal was the fuel source.

tim smith

If no a/c then I would go with cast iron radiators , thermostatic radiator valves, std efficiency cast iron boiler, od reset. Sizing for as low of temp as I could get away with. Solar pv on roof with Battery storage and small emergency generator for heating system and other mandatory loads.
I love high efficiency boilers but I see the 10-12 yr tco washing good portion of the savings pretty much. Sometimes there is plus savings but I do track maintenance/repair costs vs savings and its what I am seeing. With that said, I still promote high efficiency for the ecological reasons and when energy prices do rise then the benefit will be there more so.