A similar problem can occur if you "upgrade" an older house to modern sealing/insulation techniques - all of a sudden you don't have fresh air leaking in and you get things like downdrafts on the hot water heater exhaust[1].
This looks like a problem of "flat hierarchy" - there's no one responsible for anything. If a problem arises, we all just scratch our heads for a while and go back to sleep.
> I noticed that someone had placed an oscillating fan inside the ductwork, just before the indirect heater. “What’s this for?” I asked the plumber.
> “I’m trying to blow the heat upstairs,” he said. “It doesn’t seem to be working, though, and that’s what’s got me stumped. Heat rises.”
> “Actually, it doesn’t,” I said. “Hot air rises.”
> “Well, same thing, right?”
> “Not exactly,” I said. "Hot air will rise, but only if cold air can take its place."
> “I don’t get it.”
> “Come here; I’ll show you.” I followed the large sheet-metal duct back to where it met the foundation wall. “Where does this go?” I asked.
> “Outside,” he said.
> “Where outside?”
> “I don’t know,” he said. “I don’t do outside. I do inside.”
[...]
> I waded into the greenery and stomped around on it for a while. “The gardeners aren’t going to like that,” the plumber said.
> “It’s okay,” I said. “I do outside.”
> And that’s when my stomping made a hollow sound. I smiled. “Got a shovel?” He went to get one and I waited, and while I waited, I thought like air. If I were air, how would I get into this house? He came back in a few minutes and handed me the shovel. I dug down about six inches and hit plastic. Clear plastic. I moved some more of the dirt out of the way and saw the metal bars of the old air-inlet grate.
[...]
> When the gardener showed up, I explained what we were doing and how the air wouldn’t move across the red-hot indirect heaters because there was no fresh air coming into the house. He understood but then explained how ugly those ground-level grates were and how they had decided to cover them all with sheets of clear plastic, topsoil and pachysandra. “That’s why the house is cold,” I said.
> The gardener pointed to the plumber. “It’s his job to keep it warm. It’s my job to keep it green.”
> “The problem’s outside,” I said. “He doesn’t do outside. You do.”
> And we went back and forth like that for a while until the gardener reluctantly agreed to remove one of the clear plastic sheets, just to prove me wrong.
Clearly, the ultimate fault lies with the original architects, who unfairly designed a heating system that existed both outside and inside the house. But it's also interesting to note that the plumber's entire job was to understand how the house worked, and not only did he not understand it, he didn't seem to feel there was any reason why he should understand it.
>This looks like a problem of "flat hierarchy" - there's no one responsible for anything.
Yep, and it happens all the times, a classic example in construction are fan-coils:
1) the plumbers have in their contract the installation of the (new) fancoils for heating/air conditioning, they mount them and connect them to water lines.
2) the electricians bring nearby the electric line to power them.
3) none of the two have explicitly in their contract the chore of actually connecting the power to the fan-coil, the plumbers say that it is electrician's work, the electrician's say that it is included in plumbers work as they only have to bring the line.
I had a similar problem with my last house. The hot water system was connected to the A/C which had a heat pump. The A/C was supposed to help heat the water. When it failed, it was difficult to find a plumber who understands such systems and the A/C guys were uncomfortable with a hot water system connected to the A/C system.
This was exactly my fear when designing my new house - I wanted to build a hybrid (heat pump and gas furnace) air-conditioning and water-heating system for a home in a climate with very cold winter and increasingly hot summer. Despite providing charts on efficiency & cost savings, and a detailed plan for installation, I eventually gave up. If I couldn't make builders, plumbers & HVAC techs understand, I'd never be able to get it serviced; If the techs couldn't understand it, I'd never get a future buyer to understand it either.
Well, that is another issue: no (or limited) competence of the plumber.
At least here (Italy) we have two kind of workers:
1) generic plumbers (BTW also perfectly capable of installing a new A/C system or boiler, furnace, etc.)
2) specialized "boilermen" or "heat engineers", i.e. people that do the maintenance and repair of them
The level of competence of #1 above is - generally speaking - excellent, whilst the level of competence of #2 greatly varies, particularly when the issue at hand is not "normal maintenance" but rather a malfunctioning, and even more so if it is an electronic/controller related one.
Even if manufacturers do provide courses to (hopefully) keep the maintenance crew up to date with specific new machinery, these courses are often completely unuseful (as they are often theory only and very little real-life or actual field related) or they are terribly conceived or taught, with the result that only a very limited number of people taking them actually understand them fully.
To give you an example, I often deal with a "largish" plumber firm that has some 15 people, of which some 10 are "generic" plumbers and 5 are "specialized" on HVAC, A/C, boilers, etc.
Of these 5 people, only 2 (IMHO) are good in problem solving, and only 1 is at the level where all of them should be.
This latter guy is often called directly by this or that manufacturer to go and solve for them issues even 3-400 Km away, which should mean that he is a rare resource.
And every year the manufacturer engineers add some more complexity to the machines (no matter if for a real bettering or not) completely disregarding the need of forming the maintenance and repair personnel.
There is also an underlying education problem, some machines are getting so complex that only someone with a graduate engineer level has the competence to troubleshoot some issues, but of course no graduate engineer would ever dirty his/her hands in a plumber job.
> It’s how the rich got their fresh air back in the day. Fuel bills were not a concern.
I once had a tour in a now-empty former Siemens office building in Munich (https://translate.google.com/translate?hl=&sl=de&tl=en&u=htt...) built in the sixties. This 75 meter highrise had the same kind of heating: cold air was sucked in through a mushroom-shaped structure at the side of the building, heated electrically in a huge room in the basement, and piped into every office room where it came in through vents under the windows. The "used" warm air was then collected and pumped straight outside again. Fuel/electricity bills were apparently not a concern for Siemens either - this was the pre-oil crisis era, plus they were a major player in the nuclear industry...
I thought this is the standard way to do HVAC in large buildings: you pull in and condition the outside air, push it through ducts ("supply flow") to every room in the building, then collect the "used" air through separate ducting ("return flow") and pull it to the basement, reclaim some of the energy, and then push it out.
(Or maybe it was? It's increasingly common to see office buildings with lots of AC units on the side walls - but I suspect that's HVAC equivalent of Conway's law: where every floor may have a different owner, it makes less sense to invest in central HVAC.)
Other than ensuring heat pumps are involved at entry/exit stage, I'm not sure how you could make it more fuel-conservative. Some wins can be had if you put enough smarts in the ducts, but overall, there's a price you have to pay for near-total control over the air.
Also, the article seems to be implying that ducts were (still are!) made from metal because it was cheap, and nobody cared about energy leakage. But it's not that - the ducts are made from metal because of friction. Over the length of the ducting, inner wall roughness adds up into static pressure your blowers will have to fight - so you want to minimize that, to save on energy use and wear.
The guy who organized the tour didn't mention anything about a heat pump - and he was the developer who had bought the building, so I guess he would have known. Heat pumps were invented much earlier, but didn't become commonplace for this purpose until after the oil crisis. Plus, IIRC the system was only HV without the AC. With added AC and heat pumps to reduce the heat loss, it definitely makes more sense...
It’s not exactly that way, though it might rhyme with that.
I think it’s more accurate to think of “air is taken from conditioned spaces via return ducts to the air handlers, where it is conditioned (filtered, heated, cooled, re or de-humidified) and then supplied via vents; separately, there may be active exchange of fresh air from outside via an HRV/ERV to ensure adequate air changes. (Many older buildings rely on leakage for the latter purpose, sometimes supported by using inside air for combustion [which will draw outside air in].)”
The difference is that the demand for fresh air is largely independent of the temperature needs of the space, so you want to decouple the fresh air supply from the temperature change. (You don’t want a massive increase in fresh air on the coldest or hottest/most humid day.)
Couldn't an waste air heat recuperation be fitted in way that would keep the architecture preserved?
Seems such a waste to have this kind of heating in this day and age. I'm guessing the temperature and humidity wary a lot inside, so if not for the sake of bills or the environment, proper air conditioning could be done for the sake of comfort.
Dan Holohan, the author, wrote the canonical book on hot water heating: "Pumping Away". I replaced all the boiler piping in my house and used this book as guidance; it's a great read if you have a boiler system.
19 comments
[ 3.2 ms ] story [ 51.0 ms ] threadAbout steam heating instead of water heating.
https://structuretech.com/how-to-fix-water-heater-backdrafti...
[1] Yes, yes, I know, but it's only a cold water heater when it starts up, then it's a hot water heater, or at least a hot water maintainer.
> I noticed that someone had placed an oscillating fan inside the ductwork, just before the indirect heater. “What’s this for?” I asked the plumber.
> “I’m trying to blow the heat upstairs,” he said. “It doesn’t seem to be working, though, and that’s what’s got me stumped. Heat rises.”
> “Actually, it doesn’t,” I said. “Hot air rises.”
> “Well, same thing, right?”
> “Not exactly,” I said. "Hot air will rise, but only if cold air can take its place."
> “I don’t get it.”
> “Come here; I’ll show you.” I followed the large sheet-metal duct back to where it met the foundation wall. “Where does this go?” I asked.
> “Outside,” he said.
> “Where outside?”
> “I don’t know,” he said. “I don’t do outside. I do inside.”
[...]
> I waded into the greenery and stomped around on it for a while. “The gardeners aren’t going to like that,” the plumber said.
> “It’s okay,” I said. “I do outside.”
> And that’s when my stomping made a hollow sound. I smiled. “Got a shovel?” He went to get one and I waited, and while I waited, I thought like air. If I were air, how would I get into this house? He came back in a few minutes and handed me the shovel. I dug down about six inches and hit plastic. Clear plastic. I moved some more of the dirt out of the way and saw the metal bars of the old air-inlet grate.
[...]
> When the gardener showed up, I explained what we were doing and how the air wouldn’t move across the red-hot indirect heaters because there was no fresh air coming into the house. He understood but then explained how ugly those ground-level grates were and how they had decided to cover them all with sheets of clear plastic, topsoil and pachysandra. “That’s why the house is cold,” I said.
> The gardener pointed to the plumber. “It’s his job to keep it warm. It’s my job to keep it green.”
> “The problem’s outside,” I said. “He doesn’t do outside. You do.”
> And we went back and forth like that for a while until the gardener reluctantly agreed to remove one of the clear plastic sheets, just to prove me wrong.
Clearly, the ultimate fault lies with the original architects, who unfairly designed a heating system that existed both outside and inside the house. But it's also interesting to note that the plumber's entire job was to understand how the house worked, and not only did he not understand it, he didn't seem to feel there was any reason why he should understand it.
Yep, and it happens all the times, a classic example in construction are fan-coils:
1) the plumbers have in their contract the installation of the (new) fancoils for heating/air conditioning, they mount them and connect them to water lines.
2) the electricians bring nearby the electric line to power them.
3) none of the two have explicitly in their contract the chore of actually connecting the power to the fan-coil, the plumbers say that it is electrician's work, the electrician's say that it is included in plumbers work as they only have to bring the line.
At least here (Italy) we have two kind of workers:
1) generic plumbers (BTW also perfectly capable of installing a new A/C system or boiler, furnace, etc.)
2) specialized "boilermen" or "heat engineers", i.e. people that do the maintenance and repair of them
The level of competence of #1 above is - generally speaking - excellent, whilst the level of competence of #2 greatly varies, particularly when the issue at hand is not "normal maintenance" but rather a malfunctioning, and even more so if it is an electronic/controller related one.
Even if manufacturers do provide courses to (hopefully) keep the maintenance crew up to date with specific new machinery, these courses are often completely unuseful (as they are often theory only and very little real-life or actual field related) or they are terribly conceived or taught, with the result that only a very limited number of people taking them actually understand them fully.
To give you an example, I often deal with a "largish" plumber firm that has some 15 people, of which some 10 are "generic" plumbers and 5 are "specialized" on HVAC, A/C, boilers, etc.
Of these 5 people, only 2 (IMHO) are good in problem solving, and only 1 is at the level where all of them should be.
This latter guy is often called directly by this or that manufacturer to go and solve for them issues even 3-400 Km away, which should mean that he is a rare resource.
And every year the manufacturer engineers add some more complexity to the machines (no matter if for a real bettering or not) completely disregarding the need of forming the maintenance and repair personnel.
There is also an underlying education problem, some machines are getting so complex that only someone with a graduate engineer level has the competence to troubleshoot some issues, but of course no graduate engineer would ever dirty his/her hands in a plumber job.
I once had a tour in a now-empty former Siemens office building in Munich (https://translate.google.com/translate?hl=&sl=de&tl=en&u=htt...) built in the sixties. This 75 meter highrise had the same kind of heating: cold air was sucked in through a mushroom-shaped structure at the side of the building, heated electrically in a huge room in the basement, and piped into every office room where it came in through vents under the windows. The "used" warm air was then collected and pumped straight outside again. Fuel/electricity bills were apparently not a concern for Siemens either - this was the pre-oil crisis era, plus they were a major player in the nuclear industry...
(Or maybe it was? It's increasingly common to see office buildings with lots of AC units on the side walls - but I suspect that's HVAC equivalent of Conway's law: where every floor may have a different owner, it makes less sense to invest in central HVAC.)
Other than ensuring heat pumps are involved at entry/exit stage, I'm not sure how you could make it more fuel-conservative. Some wins can be had if you put enough smarts in the ducts, but overall, there's a price you have to pay for near-total control over the air.
Also, the article seems to be implying that ducts were (still are!) made from metal because it was cheap, and nobody cared about energy leakage. But it's not that - the ducts are made from metal because of friction. Over the length of the ducting, inner wall roughness adds up into static pressure your blowers will have to fight - so you want to minimize that, to save on energy use and wear.
I think it’s more accurate to think of “air is taken from conditioned spaces via return ducts to the air handlers, where it is conditioned (filtered, heated, cooled, re or de-humidified) and then supplied via vents; separately, there may be active exchange of fresh air from outside via an HRV/ERV to ensure adequate air changes. (Many older buildings rely on leakage for the latter purpose, sometimes supported by using inside air for combustion [which will draw outside air in].)”
The difference is that the demand for fresh air is largely independent of the temperature needs of the space, so you want to decouple the fresh air supply from the temperature change. (You don’t want a massive increase in fresh air on the coldest or hottest/most humid day.)
https://www.mycentraljersey.com/story/news/local/land-enviro...