# HELP!!!! Please read and Answer



## STB (Feb 12, 2010)

Have a contractor that in 2006 installed AC in a house under construction, but the AC was not part of the original plan approval.  Upon finding this on an inspection, I requested a duct layout and cooling calcs for our review and approval process.  The contractor refused to provide the calcs.  The Homeowner and the contractor had parted ways due to attitude and money issues so I aided in trying to help him obtain design and calcs by contacting a local supply house that pretty much prepares these for 90% of the contractors in our area.  The supply house was willing to help the H/O until the contractor contacted them and "persuaded" them not to get involved.  So the homeowner added returns in the isolated rooms ( via transfer grills) and a Temp CO was issued.

Now the Contractor has reared his head and is back since he heard that a board member has recommended cutting my position in the township, and is requesting to review all building files submitted in the township for new homes in 2006, specifically AC designs.  We have always required them when they are proposed.

I just need a quick "yes" or "no" whether or not those of you on this Board require design and calcs for new and retrofit installs.  I am trying to show that this is common requirement in jurisdictions.  Thanks in Advance!


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## raider1 (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

All residential building permits that include HVAC systems that are applied for in my jurisdiction are required to have a mechanical system design in accordance with 2006 IRC section M1401.3.

We require an ACCA Manual J and D calculation for sizing the equipment and duct systems to be submitted at plan review.

Chris


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## Uncle Bob (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

STD,

Welcome to the forum.

"I aided in trying to help him (the homeowner)"

It doesn't appear that the contractor is going after you for demanding the requirements; but, for interfering between the contractor and the homeowner.

" (The Contractor) is requesting to review all building files submitted in the township for new homes in 2006, specifically AC designs."

Provide them in accordance with the Open Records Act of your State.

A "Stop Work Order" might have been the best way to go.

Uncle Bob


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## cboboggs (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

We require the Manual J calcs IAW the 03 IRC on new construction only, but we do not issue permits for mechanical on one and two family dwellings per the City Code.

I have to agree with UB, a stop work order would have been the way to go. While your intentions were noble by trying to assist the HO. You may have placed your jurisdiction in hot water. Let us know how this all shakes out.


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## Heaven (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

We don't require submittal of calcs or plans for residential mechanical or electrical. We do require permits and some inspections. When a contractor and an owner part ways I always encourage the contractor to write a letter to the file closing his permit and have an inspection to document where his responsibility ends (assuming that another contractor or the homeowner will be continuing the work). They are usually really happy to do that.


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## GHRoberts (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

If the contractor refused to provide documents for a permit, don't issue that contractor any more permits.

I am of the opinion that contractors are agents for the homeowner and as such you should not "stop work" if the contractor walks. If you feel that the contractor is not an agent, I guess you should procede against the contractor for violating his permit terms - he agreed to do the work according to the terms of the permit and he seems to be in vioation of those terms.


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## pwood (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

it is not too late to site the contractor for working without a permit. go for the throat if this clown is causing you grief!


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## jpranch (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

We require mechanical permits for residential and commercial. Full plans with appliance details. We do the calc's in house. I don't trust the supply houses or the contractors.


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## STB (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

Jurisdiction is not in hot water for attempting to help.  Homeowner grew up with supply houses son so he attempted to help.  The contractor has a history of violating code provisions.  He was upset with me because he didn't install hammer arrestors on the quick closing valves in his own residence when he built it.  He was persistent that his pressure tank (well tank) in his house was one big hammer arrestor.  The mentality that I am dealing with. :roll:

Really looking for responses on how many require drawings and calcs.  Appreciate the ones that have already answered and the additional comments that have been posted.


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## Mule (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

This has been a good thread. Our AHJ has not required a submittal of the calcs in the past........however we will in the near future but I need you guys to learn me sumpthin!

Actually what will these calculations accomplish???

The correct sizing of AC/heat for the house based on ???????

Size of house...energy effectiveness...

Does the amount of insulation come into play?

What about the amount of windows???.

How do you know these calcs are correct?

I'm not sure I would know how to verify for correctiveness?? Correctiveness....is that a word???? :roll: sounds like it should be!!  

Lot's of questions that I need answers for.


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## Mule (Feb 12, 2010)

Re: HELP!!!! Please read and Answer



			
				STB said:
			
		

> he didn't install hammer arrestors on the quick closing valves in his own residence when he built it.


I don't understand this one......what are you talking about? What are quick closing valves?


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## mtlogcabin (Feb 12, 2010)

Re: HELP!!!! Please read and Answer



> [What are quick closing valves?/quote]The selenoid valve on a clothes washer or dishwasher, 1/4 turn ball valves are a few examples
> 
> No calcs or plans required for residential HVAC


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## Mule (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

P2903.5Water hammer. The flow velocity of the water distribution

system shall be controlled to reduce the possibility of

water hammer. A water-hammer arrestor shall be installed

where quick-closing valves are used. Water-hammer arrestors

shall be installed in accordance with manufacturers’ specifications.

Water-hammer arrestors shall conform to ASSE 1010.

So this means EVERY residential house HAS TO HAVE water-hammer arrestors?????

Man....we sure don't require them here!


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## raider1 (Feb 12, 2010)

Re: HELP!!!! Please read and Answer



			
				Mule said:
			
		

> This has been a good thread. Our AHJ has not required a submittal of the calcs in the past........however we will in the near future but I need you guys to learn me sumpthin!Actually what will these calculations accomplish???
> 
> The correct sizing of AC/heat for the house based on ???????
> 
> ...


The ACCA Manual J calculations use the buildings thermal envelope and will come up with a heating and cooling load per room based on the wall/ceiling construction and insulation values as well as the amount of glazing and U-value of the windows. Orientation of the building is also taken into account as well as air infiltration.

After each room load is calculated then they are added together to get a total heating and cooling load.

ACCA Manual D then uses the loads generated in the Manual J calculations to come up with a duct design that will move the proper amont of air for the system.

Chris


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## peach (Feb 12, 2010)

Re: HELP!!!! Please read and Answer

Should have a design... most jurisdictions require them.

You tried to do the right thing by asking for them; the guy refused.

The board ought to listen to you; he can request all he wants... provide it after he makes a proper FOIA request and pays the applicable fees.


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## EPrice (Feb 16, 2010)

Re: HELP!!!! Please read and Answer



			
				Mule said:
			
		

> I'm not sure I would know how to verify for correctiveness??


ACCA Manual J does allow for someone to do the calculations manually on paper forms, but we have yet to see one done that way.  The calculations that we have been receiving have been done using computer software designed for the purpose.  We verify correctness by verifying that the correct values were put into the program, then assume that the program does its calculations correctly.  The trick is to get them to submit the part of the report that shows the wall types, window U-values etc. that were entered into the program.


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## STB (Feb 16, 2010)

Re: HELP!!!! Please read and Answer

If you are inspecting the mechanical system in a residential dwelling you need a design to confirm what your looking at, and without the calculations, the installer is only "guessing" at how to design the system.  That is the reason we require calcs and designs.  Can you imagine allowing a Glu Lam to be installed carring a two story home without a design or calculations, just what the contractor thought was ok :shock:   Besides, with those two documents, you can be sure that you will be out of the court room by lunch time cause you required documents and inspected the job based on those documents.  If the calculations were off after all of the correct code (local and lot specific criteria) is present on the calcs, then the designer/contractor won't be sitting with you for lunch.  It would be a different story trying to explain that you inspected something that is not in the code (the design) based on ...................... :?:

peach,

I agree.  He has requested a document that he is referring to as "AC RESCHECKS".  Not quite sure what that is.  I am going to give him a copy of the Reschecks (energy calcs) that have been submitted since that is the closest thing that I can relate his request to.

Mule,

We at least require them on the selenoid activated valves, their operation cannot be controlled by the user.


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## jar546 (Feb 16, 2010)

Re: HELP!!!! Please read and Answer

Manual J calcs required. Just told a new applicant today as we do every single time.


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## RJJ (Feb 16, 2010)

Re: HELP!!!! Please read and Answer

STB: Yes need design!


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## klarenbeek (Feb 16, 2010)

Re: HELP!!!! Please read and Answer

We don't require clacs on every job but contractors have to be able to provide them if requested.  The problem we run into is, while there is a minimum temp that has to be maintained for heating, there is no temp that has to be maintained for cooling. If the contractor wants to say he's designing the system to maintain 85 or 90 degrees for cooling, he can.   :shock:

If anyone knows where I can find that either in the I codes or ACCA, let me know. It sure would have been helpful on a few jobs in the past.


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## STB (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

klarenbeek,

The International Energy Conservation Code requires a minimum design temperature of 72 degrees for heating and 75 degrees for cooling.


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## klarenbeek (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

Thanks STB.

Unfortunately, our jurisdiction has adopted the energy code "for reference only" so unless it is referenced in one of the other codes, I can't enforce it.

After reading that section (302) though, it states "a maximum of 72 for heating and a minimum of 75 for cooling." The way it reads, a cooling system can be designed to anything down to 75, for instance, it can be designed to 80, but not to 70.  This section seems to adress the issue of oversizing equipment, not undersizing.  IRC sec. 303 gives a minimum of maintaining 68 for heating to ensure equipment is not undersized, but no max for cooling.


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## Mule (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

Well if you are reading it that way then you can't design a system that will give you no more that 72 degrees........73........heck no!!!!! Maximum of 72! :shock:


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## STB (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

After taking a closer look, I agree. The only other sections of the IRC that somewhat address this is the conditioned area definition in chapter 2, and section N1103.1.1 that addresses programable thermostats. The thermostat must be set initially at 70 degrees for heating and a set point no lower than 78 degrees for cooling. I guess you can say that the IRC requires 68 min. for heating and 78 for cooling, the system must be able to operate down to 78 degrees.

But it also states that the thermostat must be capable of setting back or "temporarily" operating the system to maintain the zone down to 55 degrees and up to 85 degrees.

Too many numbers.....my head is strating to hurt again :?


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## Forest (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

STB,

    You can also use Section 106 of the IRC that states as BCO you can require as much documentation as needed to determine compliance with the code.


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## TimNY (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

Hey Mule,

I feel your pain.  No calcs required here, even though I know they are required.  It's just not something that has ever been required in this geographic area.  I have my hands full trying to enforce other provisions of the code that have been overlooked for years.  You gotta pick your battles.

I'll also admit I'm in the same boat as far as water hammer arrestors. I've used them on my own projects just because that's what a quality job demands.  Did not realize the code _also_ demands them.  Can't wait to pull that one out at the next rough inspection.  Better make sure my means of egress is compliant, because I'll probably need it.

Tim

aka the "nitpicker" as I was recently called


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## klarenbeek (Feb 17, 2010)

Re: HELP!!!! Please read and Answer

We're still under 2006 Irc and switching this summer, but wouldn't you know it, that section (programmable stats) is getting amended out (a concession to our mechanical board for other items to be added or changed).

One of the other inspectors here had to deal with a similar situation.  A contractor put in an a/c in a small office building that would barely take care of the light load, let alone anything else, because "that was the size the building owner wanted"! :roll: He aske for calcs, and the design temp was 90.

That same inspector went to a seminar where the instructor mentioned to old method of "standing at the curb with a cardboard template, if the house fit in this hole, it got this size furnace."  Afterward, someone was asking where he could get one of those templates!

Tim, we have the same problem here, especially before it slowed down, so we decided to go with the "if it seems out of whack, request load calcs." No mech inspections in city limits prior to '94 and still no mech inspections elswhere in the state except Rapid City, 350 miles away.

By the way, if you never get accused of nitpicking or picking on someone, you're probably not doing your job.


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## mtlogcabin (Feb 17, 2010)

Re: HELP!!!! Please read and Answer



> The International Energy Conservation Code requires a minimum design temperature of 72 degrees for heating and 75 degrees for cooling.


Correction

The International Energy Conservation Code requires a maximum design temperature of 72 degrees for heating and a minimum 75 degrees for cooling.


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## STB (Feb 18, 2010)

Re: HELP!!!! Please read and Answer

mtlogcabin,

Sorry, my bad!


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## peach (Feb 20, 2010)

Re: HELP!!!! Please read and Answer

The IRC doesn't require cooling... only heating.. even in Miami..

In areas where heating clearly rules (like the northern climates), you'll always design for heat..

In southern areas, you'll generally design for cooling (didn't I see hats and mittens during the Fat Tuesday parades on TV)..

Since supplemental heat is always required (well, talk to the people in New Orleans).. bet they are glad they had it..  and that's the Code requirement.. you need to at least consider it in the South.

I live in a "southern" state... watching our 60+ inches of snow melt away...

Always get calculations if a mechanical system is installed.

I wish my place had been designed for efficient heating... but it's not.  Not a good provision for return air.


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## STB (Feb 23, 2010)

Re: HELP!!!! Please read and Answer

peach,

What WAS your snow load?


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