Do I need a general contractor to build a house?

[jk96]

To be clear, I should have said it was very hard to find an HVC contractor that would create the metal duct to go from the closet to the attic. In the end, I found several and went with the bid from the contractor that did the big commercial jobs in my area, including the airport. I believe that they did a good job making it, and that they did a good job of sealing it. But I was in a house last week out at the lake that is considered very high dollar, and it has both metal and flex ducts in it's attic. Guess which ones where keeping me cool while I was up there?

To say that metal is better because it flows better ignores the simple fact that metal ducts leak and flex ducts don't. While you might have your ducts sealed good enough to never leak anytime in the future, odds are very good that if you look at ten other systems with metal ducting, 9 of them will have leaks. In my opinion, best practice is to use what will offer the best chances of success over the longest period of time.

Eddie I agree with you on most every post but advocating flex over hard pan duct because someone can't seal them correctly is something I can't get on board with. So much pressure drop and potential for kinks/restrictions with flex.

Here's a few pics coming off one of our two hvac systems in the home. Red and green lights are the zoning dampers. All custom hard pan and even the short runs off trunks are hard round metal including those in our basement into our drop ceiling. Not a single piece of flex and proper sealing at all seams.

 

[JasperFrank]

I quickly went through three different GCs before deciding to do it myself. Two major factors influenced this decision. First, was that the house was a Geodesic Dome, and none of the GCs had any experience building one. They tried to apply standard methods to the construction and attempted short cuts when ever they ran into a problem. I suspect that two of the GCs had never built anything that required so many compound angled cuts. The subs they hired were even more clueless.

Second, was that I didn't take out a construction loan. I had enough cash to cover the whole project, so I could take my time. All the subs I hired were "Time and Materials," and not bids. This worked out as the subs couldn't work out what a fair bid was anyway.

Being my own GC was one of the greatest and most full filling tasks I'd ever taken on. It took several years to finish the house. But I learned near everything one could about construction. I know where everything was done, how it was done, and the quality of the workmanship. And if anything needs to be maintained or fixed, I know how to do it.
Plus, I could rationalize buying all sorts of tools that were then mine to use.

 

[Steppenwolfe]

Yes, it's amazing how different things are done in different areas of the country. When I insisted that the HVAC system was installed in the utility closet, I was told by several HVAC contractors that it wasn't possible because nobody could create a metal duct to go from ground level to ducts in the attic.

While I don't agree that you are correct on your comments on ducts, I do agree that what is done around the country varries significantly on those unique areas.

There is night and day difference what HVAC is in residential vs commercial. We don't allow flex duct runs more than 5 feet, and that is after a hard elbow. I won't even get into ducted returns for every room.

 

[Steppenwolfe]

To be clear, I should have said it was very hard to find an HVC contractor that would create the metal duct to go from the closet to the attic. In the end, I found several and went with the bid from the contractor that did the big commercial jobs in my area, including the airport. I believe that they did a good job making it, and that they did a good job of sealing it. But I was in a house last week out at the lake that is considered very high dollar, and it has both metal and flex ducts in it's attic. Guess which ones where keeping me cool while I was up there?

To say that metal is better because it flows better ignores the simple fact that metal ducts leak and flex ducts don't. While you might have your ducts sealed good enough to never leak anytime in the future, odds are very good that if you look at ten other systems with metal ducting, 9 of them will have leaks. In my opinion, best practice is to use what will offer the best chances of success over the longest period of time.

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Eddie I agree with you on most every post but advocating flex over hard pan duct because someone can't seal them correctly is something I can't get on board with. So much pressure drop and potential for kinks/restrictions with flex.

Here's a few pics coming off one of our two hvac systems in the home. Red and green lights are the zoning dampers. All custom hard pan and even the short runs off trunks are hard round metal including those in our basement into our drop ceiling. Not a single piece of flex and proper sealing at all seams. View attachment 727059View attachment 727060View attachment 727061

That's what I have in my home for each of the 3 units. And ducted returns from each room.

 

[dstig1]

That's what I have in my home for each of the 3 units. And ducted returns from each room.

Same here, and just like jk's pics. If they are properly sealed they won't leak. And yes, ducted returns from almost every room (not bathrooms)

But another one of those regional differences: all my ductwork is within conditioned space. If there IS a leak, it doesn't mean it is heating the atmosphere, but rather just causing a bit of imbalance in the amount of air that should have made it to the end of the run. It is still conditioning the house, just not quite as efficiently as it should. This is typical around here.

 

[jk96]

Same here, and just like jk's pics. If they are properly sealed they won't leak. And yes, ducted returns from almost every room (not bathrooms)

But another one of those regional differences: all my ductwork is within conditioned space. If there IS a leak, it doesn't mean it is heating the atmosphere, but rather just causing a bit of imbalance in the amount of air that should have made it to the end of the run. It is still conditioning the house, just not quite as efficiently as it should. This is typical around here.

We have a timberframe home with the underside of all rooflines spray foamed so our duct is all in conditioned space as well. Hvac units are in a conditioned basement one on each end of the home.

 

[JasperFrank]

Electical heating is near always 100% efficient. If designed correctly. There is no waste heat. Lighting is also heat. I found, and ran into to the modern problem that Code can not understand that lighting can be a heating source. Incandescence bulbs are horrible at making light but they are good to make heat. And for some reason we want to get rid of incandescent lights as being inefficient. Well they are not, they are a heat source also and do a dual propose: They heat and light. There is no inefficient use here as they do two things: They heat and they light: Its a win win to get light and heat from the same place. Code says something else, that I don't understand. I can heat the entire house just using the lights, which was part of the design. But cultures change, and ones ideas become out dated if the culture wants you to do something else, and to buy something else.

 

[jk96]

Electical heating is near always 100% efficient. If designed correctly. There is no waste heat. Lighting is also heat. I found, and ran into to the modern problem that Code can not understand that lighting can be a heating source. Incandescence bulbs are horrible at making light but they are good to make heat. And for some reason we want to get rid of incandescent lights as being inefficient. Well they are not, they are a heat source also and do a dual propose: They heat and light. There is no inefficient use here as they do two things: They heat and they light: Its a win win to get light and heat from the same place. Code says something else, that I don't understand. I can heat the entire house just using the lights, which was part of the design. But cultures change, and ones ideas become out dated if the culture wants you to do something else, and to buy something else.

Many of us have an equal amount of heating and cooling through the year. I wouldn't consider it a win in the cooling season nor much of a win in the heating season with that heat being in the highest part of the home where it is not needed and most likely to escape. I'll stick with more efficient led and let the hvac put the heat/air where it is designed to.

 

[Sberry]

If i am gonna build it myself what is it i need the subs for again?

 

[Steppenwolfe]

If i am gonna build it myself what is it i need the subs for again?

To cut out those greedy @$%^&%*$ General Contractors...