1920s brick veneer Tudor
Good morning. I bought a 3400 sqft Tudor home built in 1927. As is normal with many homes this old, their are many idiosyncrasies (to say the least). My biggest issue at the moment is comfortability. This is a 3 story house where the attic was finished into the master bedroom (3rd floor) and the second floor has all of the other bedrooms. The house has two cast iron boilers and two Ac systems. There are lots of issues with the heating zones. When they created the addition they added all copper fin baseboard heat. However, the left the original cast iron radiators in the second floor bedrooms and on the first floor. The second floor also has a 1000sqft great room with all baseboard heat. The boiler that controls the first floor radiators also controls the second floor bedroom radiators. The second boiler controls the baseboard radiators in the kitchen on he first floor as well as the second floor greatroom and the 3rd floor master. This created issues with having to run both boiler to effectively and evenly heat certain areas of the house.
A solution would be to properly zone everything but with the mishmash of copper fin and cast iron radiators, chattering relays and I’m convinced that the boilers are oversized, so a system overhaul is likely needed. I have read enough articles on hydronic heating to know that industry professionals prefer hydronic to forced air.
I am really considering forced air for the following reasons:
1. new system more affordable than new boiler system.
2. I can have a properly functioning humidification system.
3. Free up valuable floor and ceiling space in basement (boiler still utilizing old gravity piping some of which are 4” in diameter.
4. Forced air probably more appealing to a wide range of possible future home buyers.
My major concern is that forced air will heat the house as well plus after I remove all of the radiators there is no going back obviously.
A cost comparison between forced air and a new hydronic system would also provide clarity I guess. The main issue is finding a qualified HVAC pro in my area that can do the proper load calculations and who has experience with boiler AND furnaces.
One other thing is that the house is not insulated so I’m trying to determine if that would be advantageous and if so, blown in cellulose in an old brick veneer?
i knownthis a lot of rambling. I guess in the end it would be ideal to find a local (chicago area) consultant that could see the house. Absent that situation can anyone way in on replacing a 20 year old double cast iron boiler and AC system with a high efficiency forced air system? I would also appreciate comments on insulating an old brick veneer house given I have already replaced windows, doors and there is no attic to lay insulation. Thanks!!
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Replies
Running ducts requires volume for duct chases. You may have to demolish quite a bit of interior space to get there. Sometimes getting rid of a chimney buys enough to get he vertical duct runs, but not always.
It's likely that a solution involving a single modulating condensing boiler operating off outdoor reset control and some TRVs on some of the radiators can fix most or all of the comfort issues of your crazy-quilt multi-boiler, multi-radiation-type system without having to rip open the house to create space for ducts. While it's desirable/easier to implement if zoned floor by floor, it's usually possible to get there by other means running it as a single, primarily low-temperature zone. With the baseboard zone may need to be run separately and at a higher temperature- there would be trade offs, but it doesn't have to be multiple boilers to get multiple temperatures.
Thanks for the quick reply. The house is ducted for AC. I have two airhandlers and two condensers. I should’ve been more clear.
If any of those ducts or air handlers are in the attic, above the insulation this could be a pretty serious efficiency drawback. Their suitability for heating use would have to be assessed as well.
It's also possible that the ducts could be used for a heat pump solution.
Too many variables to get into, but in general there is usually a double-digit percentage efficiency hit for ducted air vs. hydronic heating, even when the major issues can be avoided.
Hi flash007 (be great to have a real name to share with the GBA Q&A community) -
I would start with a BPI-certified audit/auditor and go from there; you need to understand your building enclosure and mechanical systems to work on either or both, and an audit is the best place to start: http://www.bpihomeowner.org/find-a-contractor
Peter
Thanks Peter I totally agree. Thanks.
Tom Lawson
Tom,
Around here there a bunch of older homes that were converted from hydronic to forced air in the early 70s and 80s. Without fixing the evelope, they tend to be very uncomfortable. Leaky old homes with rads are way more pleasant.
In terms of insulating the older section, dense pack cellulose is your friend provided your bricks are in decent shape. Best is to take a look around your neighborhood for houses of similar age and construction. If you see a lot with bricks spalling above the foundation height, you might have issues (this is a good read https://www.greenbuildingadvisor.com/article/insulating-old-brick-buildings ). If this is the case sometime you can still insulate these houses with interior spray foam, but I doubt it would be worth the cost unless doing a major reno.
If you can insulate the older section, depending on the sizes of your boilers, you might be able to get the whole house running on one of the existing boilers. With some rezoning and outdoor reset, the mix and match of high mass/low mass radiators won't matter as much.
The easiest way with the older setup is to remove the long runs of iron in the basement only keeping the risers to the rads, then home run those to a manifold by the boiler. The new pex pipe can run through the joist giving you all the ceiling height back in the basement back. This by itself is worth the cost of redoing the pluming.
With a home run system, you can now set the right flow for each rad eliminate most of the comfort issues. Depending on the capacity of your boiler and your rads in the house, you can probably split the system to 2 or 3 zones. When your boiler gives up the ghost, this setup is ready for a condensing boiler.
Great info Akos. I reached out to the guy who did an energy audit for me when I bought the house 3 years ago. He was helpful but I bought the house in May and the weather was mild so thermal imaging and some of the other techniques weren’t as helpful.
As part of his inspection he comes back out to rest after his recommendations have been implemented so he owes me a “return visit”. He is BPI certified. When he came out the first time he focused on the envelope more than my heating and cooling system which he tested and said it was working as it should but we did not get into whether it was oversized or anything else about it. This time I’m thinking about asking him to do a heat loss calculation and to discuss some of The comments from this forum.
In the meantime, I have a thermal camera and have noticed that some walls are signifantly warmer than others. I pulled the receptacles out of some of he walls and found that some of the older walls appear to be insulated with fiberglass batt as I can see the paper backing through the junction box. I’m not sure if they had to replace some of the plaster walls so they insulated at that time. The wall temp on one of the bedrooms last night with the apparent insulation was 75 degrees whereas the adjacent room with a wall facing the same direction was 61 degees. Very odd. I do know that when I had the windows replaced the installers commented that th walls were not insulated. Thanks everyone.
Tom
One other thing. One of my biggest concerns is having the expertise to make the right decision and part of that will be having an HVAC that knows what he is doing. That’s other thing I did when I bought the house was hire a BPI certified HVAC companycome out and explain the ins and outs of my boiler and AC system. I was less than impressed. They charged me $500 and were there for two hours but had questionable knowledge about how everything worked. I feel like I did my due diligence but I still did not receive the level of expertise I was expecting. My father in law was actually more helpful and he’s knowledge was as a commercial building engineer for Macy’s back in the day....
Akos I read the article in your reply and it looks like it pertains to masonry structures. Even though it was built in he 20s my house is brick veneer so it has an air gap and sheathing between the brick and the interior plaster walls. You also mentioned redoing the plumbing with pex amd utilizing due cast iron boiler. That is a fantastic idea, which I never though of. However, the boiler is venting into the chimney which happens to be right in the middle of my home Gym. The rest of the HVAC ie the air handlers, boiler zone valves,manifold, expansion tank, etc are clear on the other side of my basement in a utility area. Ideally I would like all of that grouped together into one utility area so I can clear the space for my home gym. I’m guessing there is no way vent a passive boiler to the outside without a chimney or even retrofit it with a power vent of some kind correct? Thanks again.
Tom,
Whether it is double brick or brick veneer, it is the same issue. With insulated cavity, the brick on the outside is colder. This combined with moisture from interior air leaks, water leaks around windows and usually non existent venting details for the air gap behind the brick, can take its toll on the bricks. This is very much house and brick quality dependent so there is no easy answer for it, best way to take a look around the neighborhood.
Moving boiler vents is not cheap. You can run a new vent, easiest is probably an exterior one, but this would cost more than a new boiler. No way to convert to power vent. Probalby the best would be to see what you can do to reduce heating loads (insulation, air sealing) and see if the whole house can run off the boiler in the utility room and just remove the one in the middle of the basement.