Heating Ductwork Replacement/Clean/Move

[Gary_NY]

Hi All,

I have a 1978 Shult (I think) 14x60. It has a Miller oil/hot air furnace with the main duct running down the middle front to back. This is awkward, since the registers intrude into traffic areas, especially the kitchen/dining area. It makes furniture placement difficult, plus, it's full of "who knows what" after 30 years of service. If I remember right, it looks like it's made of insulation board run between floor joists, rather than metal ductwork.

I would like to know if it's possible to clean this main duct, replace it, and/or move it to the outside wall with registers under the windows? It's my understanding this location provides more efficient heating. I also have a 30x14 attached addition harboring several rooms with flexible insulated ducts, which run off the main duct. Any help or guidance would be appreciated!

PS- I tried the shop vac with long hoses and found it to be pretty much useless.

[Robert]

Hi Gary,

Cleaning is not a possibility with insulated duct board.

Removing and relocating can be a huge task with having to repair alot of belly openings in the process.


It would be best to have a contractor look at it and advise.


Alot to consider and different ways, so alot of homework involved.


Just not a task that can be really advised on from here.



Take care and best wishes,
Robert

[Gary_NY]

Thanks Robert!! That's probably sound advice, as it looks like it'll be a major job. It's a pretty tight space to work in.

As a disabled vet, I live on a fixed income, so hiring a contractor isn't so practical for me... one of the reasons I bought Mark's book. We bought this place about 8 years ago cause it was something we could pay for in a few years.

Everything seemed good for the first couple years, then one day while I was sittin' on the john, I realized my knees were gettin' closer & closer to my chin. Needless to say, I had to replace the batroom floor and rip out the fancy tile shower. Apparently, the one who installed it never bothered to put in a pan or any kind of water proofing under the tile floor of the shower. It destroyed the whole floor, & the insulation & belly wrap underneath ( it was so full of water... it was resting on the ground). Had to replace the whole bathroom and patch the belly with a blue tarp (all I had).

I'm pretty sure ductwork ain't too cheap and having to pay someone else for labor will probably drive it out of my range. When whoever it was installed the duct extension for the flex hose to the addition, they made a real mess of it. The main duct isn't strong enough to support the weight of the extension, so it kind of ripped the main duct apart.... there's duct tape & wire everywhere.

Anyway, I thought I'd join this forum and pick up some ideas about the best way to attack all the things I have to get done. There's a whole list of things, so I'm trying to plan it all out and decide what to do when. I figured I could do some of the work underneath and inside the place over the winter. I'll have to attack the windows, roof & siding when the weather breaks. Meanwhile, the critters under the house are probably pretty toasty along about now. Thanks for gettin' back with me there Robert and you & yers have a Happy Holiday season!

[Robert]

Hi Gary,

I was only referring to a contractor to consult and advise, not do the work unless you needed it and it was affordable.


Have the contractor do what I can't and that's see it.


Also, when the addition was added, did they upgrade the HVAC and figure in added duct length ?


All this may be askew also and if so, a future headache coming.


Moving the ductwork from middle is not what I would recommend for it being a MH especially.

Would be hard to impossible to run along outer edges . Unless home is very well insulated with top grade windows and doors, wouldn't be good idea. You would lose heated air from outside infiltration through poorly insulated construction.

Merry Christmas and Happy New Year.


Take care and best wishes,
Robert

[Gary_NY]

Hi Robert,

I actually have had 2 contractors over to give me an estimate on the job and what they perceived to be done. The roof, siding, windows & doors were easy, but both pretty much walked away scratchin' their heads about what to do underneath.

The heating unit, a Miller Model MOC 80-1, 68,000 BTUH, is the original unit. The pump, blower motor, nozzle, electrodes and electrical box have all been replaced within the last couple years with no burner upgrades that I'm aware of. Surprisingly, it heats the 14x60 MH and the 14x30 addition unifromly without a hitch. I can't say if it's over-stressed, just that it doesn't cycle any more than others I have seen.

I was told by the heating contractor that placing the registers on the perimeter, particularly under windows would improve the heating efficiency.... something about thermal layers I think.

One of my upgrade projects is to replace the furnace with a larger unit that includes central air. The new models are much more fuel efficient than what I have. I can use the old one out in the garage.

Anyway.... just lookin' for ideas Robert... this old main duct is real garbage in my humble opinion. It doesn't look like something that can readily be replaced... more like it needs to be refabricated. Take care!

[oldfart]

Gary I'm awful late getting to this post but thought I'd jump in and warn you of something. You mentioned "the new furnaces are much more effecient." Gary...no they ain't..sorry to say. I've checked some (not all) available replacement oil furnaces for my 1970sw. and they are not 1 bit more efficient. Just 80% effecient..same as my 35 yr. old Miller. Go figger? They can make a gas furnace 99.9% effecient! Now there are still some good reasons to upgrade and I will likely do so. The new units are much safer! They're quieter also. Changing filters is easier. On the downside they're a lot more complicated to work on...computor gizmos and such. And I'm still not sold on their reliability given the gizmos. In 20+ years I've replaced 1 pump and 1 transformer. Normal maintenance is to replace the fuel filter, nozzle and clean the transformer contacts and pull and clean the blower motor every year. Now the new ones..hmmmmm? Can the average Joe do it? Just my humble thoughts my friend. Audie..the Oldfart..

[Gary_NY]

Gary I'm awful late getting to this post but thought I'd jump in and warn you of something. You mentioned "the new furnaces are much more effecient." Gary...no they ain't..sorry to say. I've checked some (not all) available replacement oil furnaces for my 1970sw. and they are not 1 bit more efficient. Just 80% effecient..same as my 35 yr. old Miller. Go figger? They can make a gas furnace 99.9% effecient! Now there are still some good reasons to upgrade and I will likely do so. The new units are much safer! They're quieter also. Changing filters is easier. On the downside they're a lot more complicated to work on...computor gizmos and such. And I'm still not sold on their reliability given the gizmos. In 20+ years I've replaced 1 pump and 1 transformer. Normal maintenance is to replace the fuel filter, nozzle and clean the transformer contacts and pull and clean the blower motor every year. Now the new ones..hmmmmm? Can the average Joe do it? Just my humble thoughts my friend. Audie..the Oldfart..

Thanks Audie! I guess like all things, there is a maximum point of return that can be reached for efficiency too. LP Gas is a more efficient burning fuel than oil per gallon, but not per btu/hr. Based on what I've been able to uncover, it ain't any cheaper than oil heat. LP Gas ought to be a lot cheaper than it is based on our reserves and production capabilities, but they've made the prices artificially high to gouge American consumers. Fossil fuels don't appear to have a very affordable future. It's shameful!

Anyway, Geo-thermal is the way to go today and if I can figure out how to get enough loops in the ground to make it work, that's the direction I'm going to head. Regarding the fiberboard ductwork, I'm gonna have to replace it no matter what, and I guess it's just a matter of figuring out what to replace it with.... fiberboard or metal. Either way... it ain't gonna be cheap.

[oldfart]

Aye Gary I'm with ye on the geo-thermal heating. I wonder if the new Pex plumbing might be the way to go on that. It's relativley inexpensive, conducts and holds heat well. Doesn't have the problems copper pipe has with acidic soil and such. The new fittings have eliminated the expense of special tools and crimping devices. Hmmm? The quandry of metal vs. fibre ductwork has it's pros and cons. Metal ductwork is less expensive and easier to work with..most of the time. But it looses heat rapidly and conducts fire from one point to another rapidly. Fibre-ductwork has a much higher R-value and in case of a fire collapses and may prevent a fire from traveling. Lots to think about. As far as furnaces..I'm still sittin' on the fence. I don't have a problem with new&improved. I use a computor! But..am I going to see a bunch'a warning stickers announcing.."No User-Servicable Parts..call a teck and pay them $70 an hr. to tell me my widget-gizzy needs replaced." Yup..most of the new furnaces have self-diagnostic thinga-ma-jigies. What they tell ya is..."You can't fix it..call the tecks and grab yer checkbook!" Hmmm? Sounds a lot like my new van/truck/SUV!! My old 1970 GMC got the same gas milage as my "new" 1995 Astro gets. But the truck had points and a carb....I could fix that. I can't even FIND the sparkplugs in that van! I replaced the radiator in the truck for (new) $80. Just had the radiator replaced in the van...couldn't do it myself..$350 for the radiator...$200 labor. Hmmm? New and improved isn't always what it's cracked up to be. JMHO of course. Audie..the Oldfart...