Best approach for 19th century Greek revival house

Bob_Freeman

We have a 7 bedroom Greek revival farmhouse near Pittsfield, MA ca. 1840. The main house is mostly original: wood frame with lathe & plaster and clapboards. It’s got oil-fired steam heat. Ceiling heights are less than 8 feet.
There’s a more recent kitchen wing which we will remodel. The kitchen wing heating will be separate.
In the main house, we must upgrade plumbing, electrical and replace the boiler. The piping and radiators are serviceable (presumably). The entire house has been drained and shut down after Thanksgiving.
We want to make an HVAC plan for the whole house but these questions pertain mostly to the original main house:



Priorities:
• Keep it as original as possible (walls, windows, etc.)
• Provide year-round heat in at least some of rooms.
• Add A/C everywhere.
• Restore the steam system.
• Make it reasonably (not extremely) efficient.
Possibilities:
• Heat only some of the rooms and leave others at minimum temperature (if that’s possible without creating condensation/moisture problems)
• Use splits.
• Keep the steam system as a supplement or back-up.
• Rigid foam insulation under the shingles
• Upgrade the exterior storm windows.
• One contractor wants to create an interior separation barrier in the main house so there’d be a cold part and a warm part. He wants to use propane-fired forced air. It would require modifying the walls.
Questions:
• How to control the moisture problems when heating only some of the rooms?
• Does adding insulation create moisture problems?
• Are splits a practical choice? Are they too ugly or noisy?
• Are splits cheap to use with solar incentives?
• Is the steam system too expensive to restore?
• Should we use an oil or propane?

SuperTech

Stay away from propane and ducted heating and cooling. They will probably butcher the house installing ductwork. Use the steam boiler in the winter months and use mini splits the rest of the year.

Jamie Hall

A few comments here...

On moisture. Excess humidity is absolutely lethal to a lathe and plaster finish. It degrades the plaster, then the keys fail, then the ceiling comes down. Therefore... whatever you decide to do in terms of heat, if part of the house is to be used, you will have a problem with the plaster in the unused part of the house; it is almost impossible to keep the humid air from the used part of the house from getting into the unused part. If you can keep the unused part walls above the dewpoint, you should be alright on that -- but that really means keeping the unused part above 55. The contractor who wants a separation barrier and propane forced air is not someone you want working on your house.

The best way to get heat is to restore the steam system. Other than a new boiler, it probably won't need much work other than possibly new vents and traps, and may not even need that. However, that said -- get someone who knows steam and knows it well. I would highly recommend you get in touch with Charles Garrity ( @Charlie from wmass ) to look over the system and install the boiler and fix what needs fixing. The man is busy -- but worth waiting for. This will be your least expensive option for getting a nice warm house.

Oil or propane? You'll hear arguments both ways. They are more or less equally expensive over the long run -- some years one will be less, others the other way around.

Exterior storm windows. Are there existing storm windows? The old fashioned kind you take down, or triple track combinations? Triple tracks work pretty well, and you may not gain much, depending on the upgrade. There are several firms which make interior storm windows, such as Innerglass (http://stormwindows.com/) which are excellent -- if a bit pricey. Do not replace the main windows; a competent carpenter can adjust even really old (like 200 years) double hungs so they are remarkably tight.

Insulation on the outside -- just under the shingles -- won't create a moisture problem if its done properly. Put a vapour barrier next to the original sheathing, then your insulation, then your shingles. This approach is not inexpensive -- the insulation part is, but adjusting all the exterior trim on all the windows and doors is finicky to put it mildly.

So -- bottom lines here:
• How to control the moisture problems when heating only some of the rooms? Almost impossible and not recommended. The potential moisture damage will cost more than the extra fuel.
• Does adding insulation create moisture problems? Not if it's done right.
• Are splits a practical choice? Are they too ugly or noisy? Not only practical, but probably the only way to get A/C without tearing up walls and such for ductwork.
• Are splits cheap to use with solar incentives? no useful comment -- incentives vary by the minute and the local politics.
• Is the steam system too expensive to restore? It's your least expensive option to get heat -- and by far the best.
• Should we use an oil or propane? Up to you. There are advantages -- and disadvantages -- to each.

Solid_Fuel_Man

A high velocity like Unico system could provide you A/C with the least amount of destruction as possible. Do you have a full basement?

I've installed ducted splits. Then you dont have things hanging on the wall, also keep in mind that every split need to have a line set go to it. This is done either with slim duct either on the outside or inside of the house.

High velocity ducts are small insulated hoses which can be fished in walls provided you dont have obstructions which is anyone's guess, some investigations are in order.

I lived in Pittsfield in another life, loved traveling I90 through the Berkshires! Is the big GE plant still in Pittsfield?

Gordy

Ditto on a High velocity system. Mini splits certainly will do nothing for the looks inside, and out.

Jamie Hall

Yes, Unico type systems will work, and when they do work work well -- if they are very carefully engineered and installed. A number of museums and historic houses do use them. If the house really is mid to later 19th century and not post and beam (earlier) it might not be that much a hassle to get the small diameter ducts up through the walls, or at least some of the interior walls. Exterior walls can be problematic, depending on the foundation and sill construction.

I don't know of a competent designer and installer in western Massachusetts; you might contact the Trustees for Reservations of just go and visit Naumkeag (in Stockbridge) and see what they did, or Chesterwood, also in Stockbridge.

For @Solid_Fuel_Man -- the big buildings for GE are there, but GE isn't. The cost of site remediation for some environmental work which was being demanded was a lot more than the money they could make on the operation, so they closed it up. Left a lot of people out of work... not getting into the politics (which it was) of that one.

Bob_Freeman

Hi Jamie

Jamie Hall said:

A few comments here...

-If you can keep the unused part walls above the dewpoint, you should be alright on that -- but that really means keeping the unused part above 55.-

That sounds practical: keep some rooms at 72, others at 55. How much less oil do we use at 55? 1/2 or 1/3 less? Would we have to police people to make sure they're not using humidifiers of showering excessively? Can we let it go to 45 when we're not there?

Jamie Hall said:

-Exterior storm windows. Are there existing storm windows? The old fashioned kind you take down, or triple track combinations?-

There are existing track type exterior storms.

Jamie Hall said:

-Insulation on the outside -- just under the shingles -- won't create a moisture problem if its done properly.-

I described that incorrectly. I meant to say under the asphalt roof shingles. I'd rather keep the clap board sheathing original if possible. Some recommend adding foam to the gap between the lathe & plaster and the sheathing but I've heard there's problems with that.

Thank you, this is an amazing amount of valuable information, Bob

Bob_Freeman

Solid_Fuel_Man said:

A high velocity like Unico system could provide you A/C with the least amount of destruction as possible. Do you have a full basement?

Thanks SFM,
There's basement under 2/3 of the main house

Solid_Fuel_Man said:

I've installed ducted splits...This is done either with slim duct either on the outside or inside of the house.
High velocity ducts are small insulated hoses which can be fished in walls....

Much of the plumbing was retrofit and we're willing to keep it exposed so we might be able to use exposed ducting. We'll also have exposed conduit.
I assume the Unico would serve as a heat pump as well.

Solid_Fuel_Man said:

I lived in Pittsfield in another life, loved traveling I90 through the Berkshires! Is the big GE plant still in Pittsfield?

I don't know about the GE plant; we're actually closer to Lee. There's still some paper plants running.
I love the Berkshires. I grew up in Albany and my wife in CT. We have lots of family in the area.
Thanks, Bob

Jamie Hall

Do not add expanding foam to the gap between the lathe and plaster and the sheathing -- as it expands in place it stands a very good chance of popping the plaster off its keys, which you really don't want to have happen. However, you may be able to get a contractor who will blow dense pack cellulose insulation in there. I am of two minds about that -- I haven't done it for the places I care for, as I'm not really happy about moisture condensing in the wall space -- which it will, since you can't get a vapour barrier in there. On the other hand, it certainly would cut the draughts and help the heat loss...

If you have people in your colder rooms (say 55), you will have condensation problems. Best not. 60 to 62 will do. And certainly no showers or humidifiers! The fuel savings are there, but I doubt that it would be much more than a quarter; that depends a lot on the degree days -- but in the Pittsfield area, that would be my guess.

If the existing triple tracks are well installed and in good shape, they work pretty well. You might want to inspect all of them first, and make sure the frames are sealed to the trim and that they panels actually fit -- they don't always.

Bob_Freeman

Jamie Hall said:

...you might contact the Trustees for Reservations or just go and visit Naumkeag (in Stockbridge) and see what they did, or Chesterwood, also in Stockbridge.

Good tip. I was also thinking of talking to the folks at the shaker village. They do an amazing job keeping up their old buildings.
Bob

RayH

Definitely insulate real well even if you need to have it blown into the walls. Continue to use a good steam boiler. For domestic hot water, a Heat pump Hot Water Heater will help with moisture issues in the basement.

Phil_17

In 2005 we started with a very similar home in Central MA. ~1835 Greek revival, steam heat (12 or 13 radiators), original plaster, original electric and plumbing. Our attic was unfinished, and we have a full basement under about 2/3 of the original home. This provides lot's of options for renovation without ruining the fabric of your beautiful old home.

Steam works great!! Between a new boiler (MegaSteam on oil is terrific) and updated vents (make sure to add sufficient venting on the mains) you should have a great setup. My experience with closing off rooms or trying to avoid heating them didn't work well: banging pipes, short cycling the boiler, and didn't save much of anything on the fuel bill...

IMHO, the biggest risk to your plaster is the electrician, followed closely by the plumber (who just want to rip it all wide open to make their job of replacing the old systems easier for them). I gave up on finding an electrician who would take the time to do it in a plaster friendly manner and rewired the whole house myself. If you take the time to figure out how the original service was installed, you can follow their example when rewiring. In our case, they had carefully cut a few floorboards and ran the wiring that way, never touching the plaster.

Our exterior was in pretty rough shape, which provided an opportunity to insulate from the outside by removing a few clapboards around the perimeter and doing spray foam in the walls. Done by a competent contractor you can get good results without damaging the plaster. We did have one small area which bulged the wall, and a few places which leaked a bit around the baseboards, but it makes the house SO MUCH more comfortable.

We went with spray foam in the attic, under the roof. I would recommend doing a thin layer of closed foam to form a vapor barrier, covered by as much open cell as you want. It will sound expensive, but it makes the house super tight and more comfortable than you would believe possible.

If you do seal it up, you must install an ERV. You will have moisture, condensation, and mold without one. In our case, the moisture comes from the crawl-space and basement, the steam does not contribute anywhere as much as what just comes up out of the ground. You don't have to run to every room in the home, but if you have attic access you should be able to cover most rooms on the second floor which does more than enough to keep ours under control.

Finally, we also had a rear portion which was "newer" construction which was falling apart. We took that down and created some new space which was implemented in a way that most people cannot tell that it's not original. The entire renovation (and the renovated bathrooms in the original part) use radiant floor heating (warmboard, 2x6 construction, spray foam). People on this forum may say I'm crazy, but we are running the radiant off the steam boiler. It has taken some fiddling and a little creative plumbing to get everything to work well, but it can be done. If I were starting from scratch, I would use an indirect tank (40 gal) instead of the flat plate heat exchanger (still may do that), but the result is fantastic. The home is draft free, quiet, and so comfortable that you honestly cannot tell whether it's 40, or 10 below outside.

When we bought the home the oil company told us that the previous owners were using 2200-2400 gal per year - heating ~3100 sq ft. + hot water. After all is said and done we're now using about 1700 to heat more than 5200 sq ft., hot water for a family of 5, and 900 sq ft. of new basement (radiant) that is set to 60°

Handyman 242

I agree with the comments about restoring the steam system; should not be a big problem and I would use it as a backup. As far as the primary AC and heating system is concerned I would use a VRF (variable refrigerant flow) system. They are very efficient to operate both in heating and cooling mode. The indoor units can be either duct-ed or non duct-ed depending on location. It would supply both heating and cooling in each room and with every room having its own thermostat. With a VRF system you do not need a home run from every indoor unit to the outdoor units but it is more of a daisy chain type of connection. I have used large crown molding to hide the refrigeration lines running in the rooms and just snaking the walls where they drop. All VRF installers have to be certified by the manufacturer so looking at a manufacturer's web site would be a good place to find a competent contractor. I know Fujitsu has design software that will lay out the complete job with complete diagrams of all piping, wiring and bill of materials.

TAG

Go slow ......

I'm one of those serial remodelers of old buildings -- love them .. it's a sickness. My current project is from 1873.

The first thing is to get a very good understanding of the building -- what's in great shape -- what's going to need replacement. What's been done and how. Evaluate the spaces available to retrofit the system you want -- as well as the cost.

You have to be a doctor --- do no harm. Understand what attracted you to the house and go with it. Once you start ripping things apart -- there is no end to it. Most contractors don't get it and can do a lot of damage upgrading plumbing and electrical .. ductwork especially.

If there is unfinished attic and basement -- more possibilities.

Finding knowledgable people will be the issue ...everyone has a different idea based on what they know and have done. Loose insulation pumped into stud cavities is a tried and true system -- it works. I have fixed more old windows than I want to think about - - they take time (and paint remover) -- Inside storms can be a viable answer.

The key is to understand what you have .... If the heating system just needs a boiler it may be wise to get the system going and live with the house for a while. But, you don't want to spend a fortune getting it all back together only to find out you want an up and down Unico type system. The house dictates -- sometimes a bathroom remodel allows access for other services if it a total gut of the room.

The mistake people make is not understanding the time and cost -- it's an old house. Trying to do too much and still not finished after a 4 year project is not what you want.

I have seen quite a few big victorians utilize mini split systems -- the branch box type with 7 or so heads ... not cheap .. but, they work ... it's all about the installer and hiding the lines.

Have used multi-head and single heads in projects with great results.

Good luck

rmoore007ri

Have an 1830 Gambrel. Gas fired one pipe steam heat. Basically moved most of the radiators around until little ones were in little rooms etc. Managed to get to the second floor with 2 pipes up. I split these so there is a radiator in each room with almost no pipe showing . . . Some are pieces of art. Refinishing most as we went along. Went for massive venting back at the furnace. Still have one radiator at the end of the line which gives the occasional "bang" . . . I've got pretty much everything written starting with The Lost Art . . . And of course learned so much on this site.

BradHotNCold

1685 Home in Milford, CT. Massive center chimney, 5 fireplaces. Not trusting the chimney, we put a permanent slate cap on top. Heating was two pipe steam. Worked beautifully. loved the radiators. Ripped off the butt ugly aluminum siding and stripped original wood clapboards off down to the post & beam frame. Installed new clapboards and copper gutters and downspouts as well as copper roof above main front door entry. Came home one day to find moisture freezing on exterior clapboards outside one bedroom. Pulled some of the new (!) clapboards off to discover that a steam pipe had split. (Think it was steel, not cast iron, not sure.) Steam had been installed in 30’s.
After much debate, decided we could not trust steam system not to let go in other walls. Ripped out steam system and radiators (sobs!) and with full basement and full attic, installed gas-fired, hydro-air HVAC with two handlers, one in attic, one in basement. Very pleased but miss radiators and steam. But it worked well. New owners crazy about house and HVAC! Another approach to consider?

vballref

An option to consider for the heating and cooling system is a hybrid system. You can install a High Efficiency Unico System with a Variable Heat Pump. We recently assisted on a retrofit of a gravity hot water system. Another contractor installed a four zone Unico system with Hot Water Coils and Variable Heat Pumps. The supplemental heat, which we installed, is two Energy Kinetics Oil Fired Hydronic Boilers. Each boiler has two zones for the hot water coils. We also installed a 120 Gallon Domestic Hot Water Storage Tank off one of the boilers. The new system is working great!
This would give you the option of using different temperatures for different areas of the house to avoid humidity issues in the unused areas of the house.
This is not a cheap option, but it is extremely efficient and aesthetically better than mini-splits in a historic house.

Underdog

Jamie Hall said:

you may be able to get a contractor who will blow dense pack cellulose insulation in there. I am of two minds about that -- I haven't done it for the places I care for, as I'm not really happy about moisture condensing in the wall space -- which it will, since you can't get a vapour barrier in there. On the other hand, it certainly would cut the draughts and help the heat loss...

If you have people in your colder rooms (say 55), you will have condensation problems. Best not. 60 to 62 will do. And certainly no showers or humidifiers! The fuel savings are there, but I doubt that it would be much more than a quarter; that depends a lot on the degree days -- but in the Pittsfield area, that would be my guess.
.

Managing moisture with any changes to to the house's insulation could be the biggest challenge. In older house there are many potential sources of water. You will always have leaks, ice dams, chimney flashing leaks, combustion exhaust, green firewood, ground moisture migration, mechanical systems leakage, wind pressure, stack-effect pressures and water intrusion via capillary action from the foundation. Ideally, the house should dry to both the interior and exterior (in heating climates like Pittsfield, primarily drying to the exterior). " When the rate of wetting exceeds the rate of drying, accumulation occurs and when the quantity of accumulated moisture exceeds the storage capacity of the material, problems occur."
The way the things stand now, your plaster walls and exterior clapboards are doing a fantastic job of managing moisture. As you add insulation the drying potential of the walls decreases (and increases with the rate of air flow). You challenge is to find the right balance. Air sealing the big leaks in the foundation, tighten up the windows, and slowing the stack-effect is cost effective without unexpected consequences. A dehumidifier in the basement can make a big difference.

brandonf

The cellulose insulation might be okay on an older house without a vapor barrier because the old-growth lumber that the house was built with is much more resistant to mold and rot. Just my two pennies.

Jamie Hall

Regarding the comments by @brandonf and @Underdog just above -- this is exactly why, in a very clearly stated way, I have not insulated the walls of the places I care for-- with, I might add, the full agreement of the trustees and vestries who pay the various bills for the heat -- and any needed repairs.

brandonf

I was considering cellulose in my place. Just because I've always been taught that insulation is good no matter what. 🤔 I guess sometimes people value efficiency over the best interests of the actual structure. Does anybody know how accurate the heat loss calculation software is? Id hate to waste money on insulation that won't get me much of an roi when it's my boiler that needs the most attention. #LimitedFunds

Jamie Hall

Insulation is good. Not saying it isn't. But -- and this is a huge but -- only if you can also install a tight (no holes for the electrical outlets!) vapour barrier on the inside, or use closed cell foam. The vapour barrier is a killer on any existing structure, unless you plan to completely remove the inside wall covering -- a non-starter on an historic plaster and lathe structure, to retain any semblance of authenticity. Closed cell foam is good, with the provision that it is very likely to pop some of either the interior wall covering (not a problem with sheetrock -- just rip the old out and smack some new up and hope no one notices) or the exterior sheathing, depending on which got nailed on better.

Heat loss calculation software varies. Some of it is better than others. Any of the better ones, though, are good to use for comparison purposes -- that is, run through the calculations with walls or windows or whatever in one condition, and then with them in another condition. This can get you a very good feel of the fractional improvement -- that is to say, will this change save 10% of my fuel? 40%? which you can then apply to your known, real world fuel usage to come up with some idea of cost/benefit.

psb75

"Good no matter what" is not a great philosophical maxim to hold.
You can have the best boiler in the world, and to what end if you cannot contain the BTU's? You'll have expensively created BTU's going to the great outdoors. Ancient sunlight going back to The Source.
The accuracy of heat-loss software is directly related to the accuracy and completeness of the DATA YOU PUT into it.

TAG

We had am old home that was cavity filled in the mid 50's -- it had to be gutted in the late 80's (fire) . I was in school at the time and was around when they ripped out all of the old lath and plaster. My parents had it done from the outside and then replaced the cedar shingles. It was big old coastal house. Whoever did it --- did a great job -- was amazed how filled everything was and we had no rot anyplace. It was some type of white fluffy insulation -- not asbestos. It was tight ..but not the wet cellulose type of tight. It really worked and I encountered it on other projects.

The goal is to get a product that still allows some air movement -- but not enough to have drafts. This way there is a natural drying depending on the season.

Tinman

I would suggest going with two high velocity split systems. One for the first floor and the other for the second.

This accomplishes a few things -

You won't have to worry about fishing the supply ducts down walls or in closets and the repairs and chases that will follow.

You're guaranteed of having a common return on each floor. This is big.

The first and second floors of single family homes have distinct heat gain characteristics. They usually are used differently over the course of 24 hours. It only makes sense to split the load to independently control each level.

Yes, keep the steam. Like Jamie said, Charlie would be a great choice.

Tinman

One more thing. I would not install mini-splits in that home. There is too much really old, character in that house and it would just kill the aesthetics.

Gordy

Listen to Stephen on the HV AC Good approach.

Gordy

About insulation.

If you are going to open up wallls either from the inside, or the outside then by all means you may as well insulate. I’d use dense pack cellulose. Never fiberglass, but that’s just me. You could do a combination of a thin layer of spray foam, and finish it off with cellulose.

I wouldn’t attempt injecting spray foam in contained wallls. One of two things will happen. They’ll be concerned with damaging the plaster, and the foam will not find its way to all the nooks, and crevices,. Or they’ll blow the plaster off the walls.


It costs money, and it’s the gift that keeps on giving. When done correctly it will last the life of the structure. While ROI is a concern, I find it different than a ROI for something that has a life cycle. Like a boiler, etc.

You could do your heat loss with the existing wall detail. Then do a heat loss with a wall detail with insulation. The heat loss difference would be how much less btus the structure will eat in a season. Projecting that fuel savings, the weather is the kicker going forward no one knows what the cost will be, let alone the weather. So ROI is a floating number.

Bob_Freeman

Phil_17 said:

In 2005 we started with a very similar home in Central MA. ~1835 Greek revival, steam heat (12 or 13 radiators), original plaster, original electric and plumbing. Our attic was unfinished, and we have a full basement under about 2/3 of the original home....

Thank you Phil,
This is full of wonderful information. My wife loves warm floors so we'll be using that for the new part also.
Can you recommend contractors? You're not too far away.
The warnings about the plaster are taken. We're thinking of keeping some of the plumbing and conduit exposed.
Thanks of for the great information about insulation and the ERV's
Bob

Bob_Freeman

Handyman 242 said:

I agree with the comments about restoring the steam system; should not be a big problem and I would use it as a backup. As far as the primary AC and heating system is concerned I would use a VRF (variable refrigerant flow) system...
With a VRF system you do not need a home run from every indoor unit to the outdoor units but it is more of a daisy chain type of connection
...looking at a manufacturer's web site would be a good place to find a competent contractor. I know Fujitsu has design software that will lay out the complete job with complete diagrams of all piping, wiring and bill of materials.

Thank you 242, This sounds like a good plan since much of the ducting will be exposed, we hope to keep it to a minimum.
Do you have other brand recommendations?
Bob

The Steam Whisperer

Regarding a vapor barrier.... most old oil based paints were pretty good at reducing moisture movement into wall....especially with mulitple layers. There are vapor barrier primers that are also available to help too (Graham paint makes one). In northern climates the key it to be sure moisture vapor can move to the outside faster than it enters the wall from the inside. Using spray foam, caulk, etc to seal all interior wall penetrations such as around outlets, windows, doors and at the joint between the floor and wall help enormously to reduce air leakage into the wall. The last location to deal with is the joist bay between finished floors, which is often open to the exterior wall (especially in balloon framing) this may require opening the floor or ceiling to install a fireblock, sealing, and vapor retarder. Sealing this area in an old basement can do wonders too. It keeps out the moist air in the summer, and then a dehumidifier can keep the basement dry (and make the whole building more comfortable. Basement stays much warmer too.

Jon_blaney

Don't forget to consider low tech solutions. Ceiling fans can make a warm day comfortable. A bedroom open window and a fans can make for nice sleeping. Your house screams stoves. Nothing like sitting by the stove in your tee shirt watching the snow blow by. Window a/c units are much improved. They weigh much less than the old ones and are not ugly like they were. You can look at the min-split head all year or a window unit for three months. Much lower maintenance and much less expensive. Zoning made easy.

Gordy

You all may find this interesting in reference to blowing insulation into walls with out the vapor barrier. There is a reason it works.

https://www.buildingscience.com/documents/insights/bsi-043-dont-be-dense

Jack M

Gordy said:

https://www.buildingscience.com/documents/insights/bsi-043-dont-be-dense

Those are impressive dense pack statistics for retrofits. Just make sure the leaks are under control
And Jon Blaney's window AC is win (may only be 2 months out of the year in the Berkshires).

Lance

Beautiful house, best not to divide in different zones. Best left as one environment, like a museum even temps and humidity control is a must resulting in less problems with uneven expansion or shrinkage. Was not a good idea to leave heat off all winter. But the bones are dry and may not have been a problem. Overall many of the comments are great. If the steam system uses air vents on radiators it will assist in winter humidity. Get a hygrometer and measure to see if need more in winter or not. If needed, add a humidifier; steam with R/O water or a fan assisted evaporative humidifier. AC: Unico is a good system, I have two of these. Critical to spend the money on extra branch ducts to keep it quiet. It is a high pressure, velocity system. It also runs the air drier in summer. Very comfortable at 78F. Usually makes the air around 40-45% RH. Traditional Ac keeps air at 45-55% RH. Museums like 50% RH on average, some exhibits require own environment. Ductless splits are great but hard to accommodate historic rules. Best energy saving bang for buck is spray foam all penetrations through the attic plane, at the basement walls and bas ceiling and any outside wall on the inside surface. It is better than adding 16" in attic, or extra storm windows. High hat lights on top floor ceilings are big air leakers. If a house leaks air the infiltration will be controlled by the wind. Most old house leak lots of air. Keep any air ducts and heat pipe inside the building envelope. Keep ducting out of outside walls. I often use inside corners of walls and cant the corner with gypsum or molding. Does a great job, uses unused space and actually makes the walls look better, "in my opinion".
I am a master plumber, HVAC, gasfitter, steam fitter, control specialist, generator tech, master builder, Yeh, I built houses in the 70's; "standards back then were poor", Building analyst for air tightness and overall evaluation. I may not know everything, but I know this, I am not wanting to know much more. Solar, pellet, wood fueled equipment, Geothermal. I am still learning new stuff. I wish things would quit changing so much! Best luck to your great project! Mind the chimney flues! If not maintained could leak!

Canucker

> @Lance said:
> If the steam system uses air vents on radiators it will assist in winter humidity.

I'm not sure how well this will work if the system and vents are functioning properly

Lance

I based it on what I see everyday in homes at least two vents are leaking somewhere. But you are right. A humidifier may still be needed.

Canucker

The steam system isn't working properly then. If it's leaking enough to affect the humidity to a measurable level, it's on a countdown to its very early demise and needs to be fixed

KC_Jones

Lance said:

I based it on what I see everyday in homes at least two vents are leaking somewhere. But you are right. A humidifier may still be needed.

This is extraordinarily bad and should be pointed out to whomever owns the home. Also no way will a couple of leaking vents effect the humidity at a meaningful level.

Gordy

For a house that was built in the 1840’s, and made it this far in the fantastic shape it appears to be in. With out all the abilities to control its inner environment like everyone is suggesting for the last 179 years or so. I think we can get a bit carried away......I’m quite sure that house has seen a rougher life than can ever be imagined.

I’m quite sure all the rooms were not identical temperatures, and humidity levels were uncontrolled. Going from 12% to probably 100% through the course of the seasons. Most certainly lacked AC.

It’s when you mix in modern technology you have to be careful on the approach.

Solid_Fuel_Man

I really think that with a historic house you really have to weigh energy efficiency against the historic part. Unless the interior or the exterior is going to be gutted/removed there is only so far you can or should go. Spray foam is a good way to seal up many areas which are unseen, but keep in mind critters will eat it up if the house isn't tight anyway.

I grew up in a roaring 1920s baloon framed Victorian. I built my own house in 2009 with slightly more square footage than my parents Victorian. I keep my place at 68 and burn less than 1/4 the fuel they use to keep their house 62. We are two towns away. But we live in vastly different houses.