View Full Version : MANUAL "D" RESOURCES
06-03-2005, 04:37 PM
Is there is Manual D program, or is it done manually? I'm going to try the Manual J software linked on this site this weekend. I would also like to know what Manual D resources are available.
Thanks very much.
06-03-2005, 04:57 PM
I use Wrightsoft's stuff. It pretty much does all the work for me. I draw the structure with the cad module that's available and as I do so, other background programs are at work figuring the load calc, duct sizes, etc. It's definitely worth checking out.
Gunnery Sergeant Hartman
06-03-2005, 11:01 PM
You're about worrisome aren't you?
Wait until your house is at least framed and call a reliable company.
You're not getting a good rtesponse because you haven't even broke ground yet and you're asking a thousand questions.
We can smell a customer that we will have to marry a mile away!
06-03-2005, 11:27 PM
Originally posted by Yellow Dot
We can smell a customer that we will have to marry a mile away!Don't knock a bad thing Yellow. We'll get half of everything when the divorce papers are finalized. ;)
(I'm just kidding nathan. I personally like meticulous customers who aren't cheap. My obsession with the details (http://hphaa.com/services/installation/installation.htm) appeals to them. Wrightsoft is good. I do Manual D by hand. It's not hard.)
06-04-2005, 10:36 AM
Yellow, I'm happily married (just ask my wife). Not being a builder I'm not well versed in the order these things should be tackled.
Thanks for the advice.
06-04-2005, 10:49 AM
Hi Nathan: I bought the manual D and have been reading, studing and doings calcs for a couple of days now. Very informative. It's expensive, but worth the money to be able to understand whats important when designing a duct system. I will use all my research to help talk intelligently with my HVAC installer when it comes time to spend some money!
My problem here in Central TN is I haven't found one yet in my area that uses one.
Nathan, you are correct to find a contractor early in the process. He can suggest changes that will allow better performance, layout and accessibility.
Running a heat load with the software from this site will give you some feel of what you need, but you need to find a contractor who can and will do the manual J and Manuel D. Duct layout is more than just a program.
And A heat load is too. Many other factors need to be taken into account on a heat load besides construction. An experienced contractor can guide you through the process.
06-05-2005, 04:08 PM
I've decided to have a mechanical engineer perform the Manual J. I've been told he will also work with my HVAC contractor on teh duct layout.
My experience in speaking to 6 recommended local HVAC contractors is that they always use an engineer. I've spoken to 2 architects and they also do not do manual Js. They also use an engineer.
One last question on Manual J. Is a room-by-room load always included in a Manual J, or is this an option?
The few homes I've seen loaded by an engineer ,were oversized.Ask if they will be doing a Manual J,or some other method.
I think they error on the side of caution,not being in the business and thinking larger is safer.
No offense to engineers,I'm sure many can do it right,just what I've seen.
06-06-2005, 12:14 AM
Can anyone recommend a good primer on zoning? Irascible's material raises interesting points but does not offer an in depth coverage. I am particularly interested in types of equipment that would work best with zoning: dual comrpessor, two stage AC and furnace, single stage AC and furnace, variable versus single speed fan, different types of controls, dampers, etc.
I know that dash has been a consistent fan of the Carrier controls (I think dash is a Carrier dealer). My dealer is fan of Trane zoning (he's a Trane dealer).
06-06-2005, 01:40 AM
check out California Economizer for zoning, we have used a lot of it with great results. Just do a google for their website, can't remember it off the top of my head.
06-06-2005, 06:41 AM
06-06-2005, 08:08 AM
Dash, you are correct in your assumption that engineers tend to oversize a little.
Being a engineer, I feel this comes from most all of our work is large commercial, with heavy internal loads.
I am working on a new dining facility right now for a university that will blow most peoples mind for the load on this building. (45,000 sq. ft. with 340 tons of chilled water on the AHU's.) Bureau fo Buildings is having a coronary, but the load is what the load is.
Anyway, back on the subject, Most engineers who do not perform many load calculations on residential work will go a little overboard with lighting, and infiltration loads in particular.
If you find someone who has a little experience and will spend the time to verify your construction, you should be happy with the load you get back.
06-06-2005, 08:13 AM
Ah come on. You make that sound like a lot. That's the old 132 sqaure feet per ton rule. Everyone knows that rule. ;)
06-06-2005, 09:11 AM
Yep, you are right, rule of thumb is always the best way to go. You will never get into trouble that way.
Thanks for the info. I didnt know that 132 sq. ft. rule. I will be sure to add it to my arsenal of quickie load calculation formulas.
Regards and have a great day all.
06-06-2005, 09:30 AM
Irascible, being a Trane dealer do you have an opinion on using the XL16i for a zoned system in Bakersfield, CA? I've received a lot of differing opinions on whether the XL16i would be a viable unit for zoning. My local Trane dealer prefers the XL19i. I've also heard that Trane does not recommend the XL16i for zoning.
Thanks, and thanks for the link.
06-06-2005, 04:22 PM
Not all Trane dealers are created equal. Thank God I'm more equal than others. ;)
But seriously... Part of being more equal is being upfront with a customer when I have no real experience with a certain product. You're not a customer. But sending me a check will resolve that little problem. Anyway, we have relatively mild summers out here. As such the 16 and 19 SEER products are purely status symbols with little real benefit to the end user. They're probably a little "status-ish" for you as well. But there ain't nothing wrong with status.
Anyway, I hate not having the answers. So I called my local factory support guy this morning. This would be one of two gentleman that works for the Trane wholesaler and whose sole purpose is to give technical support to contractors. He gets real factory training and talks directly with Trane engineers when he needs to. He indicated that there was no reason why the 16 SEER product couldn't be zoned. He said that problems with zone systems almost inevitably stem from the exact thing I mention on my installation (http://hphaa.com/services/installation/installation.htm) page: improperly sized ducts.
Having a two speed/stage compressor with a zoning system that, WILL control the stages, on an as needed basis,would seem to make it more practical,most anywhere.JMHO.
06-06-2005, 04:35 PM
Irascible and dash, thanks for the replies.
Irasacible, as to energy savings since this is a new house I don't have historical energy bills to compare. When I use the cost savings calculator on dash's website using Zone 3 it calculates that I would be saving several hundred dollars per year by ugrading from a 12 to 19 and 80% to 90+%. If this is true, combined with a local utility rebate, the upgrade makes sense. I definitely want VS even without the savings just for comfort.
I've read elsewhere that the programs used to project energy savings are not necessarily accurate.
Dash, have you seen energy savings on your upgrade installs that come close to the projected savings based on the application on your website (not to put you on the spot)?
06-06-2005, 04:38 PM
Sorry nathan. I had a brain fart. When I was thinking 16 and 19 SEER I was only thinking about the energy savings even though we're talking zones. Dash is right. Two stage AC is the cat's meow for zoning.
As far as calculators go, forget about it. The ones I've seen that use heating degree days and cooling hours are wildly inaccurate at times. If you don't have usage history then you're just guessing.
In Florida,the distributor guarantees saving of 25% of your heating and cooling costs,for going from a 10 to a 12 SEER ,or a 12 to a 14 SEER Heat pump.They pay the difference for the first year.The claims I've seen are very few,and we have always found thee was a problem,if they didn't save ,as above.
I'd think the saving would there or very close,if everything is done correctly.If I remember the zones are really too large on the calculator,so they may vary ,a bit within the zone.Can't speak for Gas savings ,if that's in your plans.
The one thing it does is factor in utility price increase ,that may or may not(so far not),occur.
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