the only Man J report I have received is the one I paid for.
It currently needs to be updated, as we made significant window and insulation changes in the weeks past
such as 1" foam and smaller windows

- I just emailed for an update and will provide it when it is complete.

Currently the outdated calcs are :
Total heating required ( with outside air ) 52,828 btuh
Total Sensible gain 36,390 btuh
Total Latent Gain - 4,974 btuh
Total Cooling required ( with outside Air) - 41,364

Now I have to have a 2 zone system, 1 upstairs in the attic and 1 downstairs in the basement

Those separate calcs are as follows :

System 1 (1141 sq ft down ) heating sensible btuh : 29,670
Cooling sesnsible btuh : 21,042
Cooling Latent btuh : 2,186

System 2 ( 957 sq ft up ) Heating sens btuh : 23,158
cooling sesn btuh : 15,348
cooling latent : 2,788


I've had a split the entire time of 3 tons down and 2 tons up, and the other way was 2 up and 2 down.




I have taken these and cross referenced the units, I called the well driller and with a 40 degree EWT I can get plenty from a 2 ton unit down and 2 ton up.

I am currently looking at Carriers GT PX split for upstairs and a Packaged unit for down.

Posted By DJV on 07 Feb 2012 07:53 AM




I have taken these and cross referenced the units, I called the well driller and with a 40 degree EWT I can get plenty from a 2 ton unit down and 2 ton up.

Most loops won't stay at 40° all winter, unless the loop is oversized.

agreed - I am trying to get an estimate from the well driller as to the minimum temps I should expect to see.

He seems to think mid 30's would be my lowest.
the proposal from him looks to be about 190 feet per ton of borehole. using 1 1/4" pipe and 20% antifreeze.

You could handle the whole house with 3 tons. Is there no oppurtunity to break ducts from the basement to the second floor?

With your modified (reduced load) 4 tons is gonna be grossly oversized.
j

thats what I was thinking - but was wondering what was going on with more then half of the contractors spec'ing 5 tons total.

I'm dealing with an existing house, from 1890 that never even had closets. so it's a real tough battle to get adequate space alotted for the correct amount of supply / returns to the second floor.

It sounds to me the 2 stage unit will not be as efficient, and almost not have to employ the use of resistance heat?

Posted By DJV on 07 Feb 2012 09:29 AM
thats what I was thinking - but was wondering what was going on with more then half of the contractors spec'ing 5 tons total.

I'm dealing with an existing house, from 1890 that never even had closets. so it's a real tough battle to get adequate space alotted for the correct amount of supply / returns to the second floor.

It sounds to me the 2 stage unit will not be as efficient, and almost not have to employ the use of resistance heat?

Okay, you really got my antennae buzzing now.

Who did the load calc? was it by print, or information you provided? Has there been a blower door test on existing structure?

We usually use the chimney chase to communicate ducts from the second floor to the basement, or double a wall up (you only need a 9" X  ~30" cavity. Upstairs load is small (and shrinking) you might be fine with ASHP (the extra 5k you spend to avoid $80/yr* in electricity does not add up)......*number from a hat; make sure to get op cost calcs to confirm.

I do not understand your last comment. The most efficient unit (heating dominated climates) is 3 stage. 1st covering ~60% of load, 2nd covering ~95% of the load and auxilliary making up the difference.
This comment makes me wonder if you learned enough to be dangerous (scaring contractors off).

A contractor must design system for home as is not for future conditions. If you wanted geo now and promised to improve envelope later, I would have to design heavy in case improvements never happen.

Posted By joe.ami on 07 Feb 2012 09:46 AM

 

Okay, you really got my antennae buzzing now.

Who did the load calc? was it by print, or information you provided? Has there been a blower door test on existing structure?

We usually use the chimney chase to communicate ducts from the second floor to the basement, or double a wall up (you only need a 9" X  ~30" cavity. Upstairs load is small (and shrinking) you might be fine with ASHP (the extra 5k you spend to avoid $80/yr* in electricity does not add up)......*number from a hat; make sure to get op cost calcs to confirm.

I do not understand your last comment. The most efficient unit (heating dominated climates) is 3 stage. 1st covering ~60% of load, 2nd covering ~95% of the load and auxilliary making up the difference.
This comment makes me wonder if you learned enough to be dangerous (scaring contractors off).

A contractor must design system for home as is not for future conditions. If you wanted geo now and promised to improve envelope later, I would have to design heavy in case improvements never happen.

I paid a conventional HVAC contractor to do my load calc based on my prints.

A blower door test has been ordered for the before test, we have to get through construction to get the after.

My current chimney will be demo'd since that wall is coming down.
I can revisit the areas where I can double up a wall.

Didnt mean to set your antenna off..lol I was thinking through your comment regarding the system being oversized.  and if it is that much oversized I would be only using the first stage ( not as efficient )  correct?

I've never even got to that point with a contractor...lol
I;ve conveyed the use of foam, and all upgrades to contractors to size the units. I have not reflected the smaller windows, as that was more recent. In my review of my ( paid ) load calc I noticed the r-value was not reflected correctly in the use of the 1" foam and batt insulation and I am awaiting a revised calc.

Thanks again for all the feedback / help - I cant thank you guys enough!

I would have to design heavy in case improvements never happen.

Really? Maybe you should design as the customer requested in the first place. In that way, later improvements might be further encouraged.

DJV,
I was in your position at one point. I had contractors not even considering open loop even though I had a running artesian well. I felt like the designs were not optimal and all sized at 5 tons (for both floors). I did the radiant floor and open loop geo myself with the help of a plumber friend. I put the system in service 12/11/11 with a three ton unit (first floor only). It is performing even better than expected and will be able to heat the second floor with the same unit. Trust your instincts and knowledge you have gained. You may forfeit the warranty but for me it is better than having it done and regretting that you were right in the first place. This forum will provide you with enough info and feedback so that you cannot go too far wrong.

Thanks - It's been a fun couple months trying to get the while house going, and this is the last part of the puzzle.

Any of you guys use climatemaster / carrier equipment?

anyone interested in genereating a bin usage report to justify my findings? I cant get that from anyone around here.

Posted By DJV on 08 Feb 2012 09:30 AM
Thanks - It's been a fun couple months trying to get the while house going, and this is the last part of the puzzle.

Any of you guys use climatemaster / carrier equipment?

anyone interested in genereating a bin usage report to justify my findings? I cant get that from anyone around here.

I'll run the bin report for you with climatemaster equipment. Where in New Jersey are you located? Any reason you do not use a single packaged unit with zoned ductwork?

My first attempt was with a single unit - there are not adequate areas to get proper supply and return ducts to and from the basement to the new second floor.

I have to deal with several existing conditions in the first floor, mainly a layout that originally had no closets...lol

I am in south jersey. -

Posted By ICFHybrid on 07 Feb 2012 09:57 AM

I would have to design heavy in case improvements never happen.

Really? Maybe you should design as the customer requested in the first place. In that way, later improvements might be further encouraged.

Really.

Believe it or not some customers lie (or scheme and dream) and yet they hold their heating contractor responsible for the out come. Silly eh?

So what a heat contractor "should" do is ensure a result he is proud of. That is the very best way to serve a customer.

Posted By DJV on 08 Feb 2012 10:50 AM
My first attempt was with a single unit - there are not adequate areas to get proper supply and return ducts to and from the basement to the new second floor.

I have to deal with several existing conditions in the first floor, mainly a layout that originally had no closets...lol

I am in south jersey. -

Since I am trying to help you, could you help me and provide me with the larger city or weather station so I can pull the bin weather data from. South Jersey is still a bit unspecific.

Trenton NJ
or Atlantic City NJ
Thanks!

Silly eh?

You can't control the scheming and dreaming. All you can do is communicate and document. If your customer says that they want to go light in anticipation of additional upgrades, doesn't it make sense to honor that?

Posted By ICFHybrid on 09 Feb 2012 01:20 PM

Silly eh?

You can't control the scheming and dreaming. All you can do is communicate and document. If your customer says that they want to go light in anticipation of additional upgrades, doesn't it make sense to honor that?

Not necessarily. I had customers who say they never set the thermostat above 65F. Then the get older, get divorced, or sell the house, and the new owner likes it at 74F. Then the new owner (or new wife) calls you and tells you that geosystem that you designed and built runs too much aux and is inefficient....... Then the new owner tells his friends and neighbors....
I would tell customers right away that I would shy away from building an under performing system. I encourage them to perform any upgrades to the thermal envelope first, so you can correctly size the geosystem. Sometimes Insulation contractors make high (and false) promises about the energy saving impact of the products they are selling. Then they point at the HVAC contractor if the house is cold.

I had customers who say they never set the thermostat above 65F

Transitory personal preference is different yet from (planned) home upgrades. Most people can understand the need to cover that.

I encourage them to perform any upgrades to the thermal envelope first, so you can correctly size the geosystem

Well that sounds like an excellent approach to me. At long last, if the customer wants to heat before insulating all one has to do is document the standards the system was built to.

Then they point at the HVAC contractor if the house is cold.

Again, you can't control other peoples bad behavior. If you have it documented that it was built as per customers intentions you are covered. I still don't see the need to puff the system up except to CYA which will saddle the customer with more cost and a lifetime of less efficiency. That is putting yourself before the customer and is not a professional strategy.

Posted By docjenser on 09 Feb 2012 03:14 PM

  I had customers who say they never set the thermostat above 65F. Then the get older, get divorced, or sell the house, and the new owner likes it at 74F. Then the new owner (or new wife) calls you and tells you that geosystem that you designed and built runs too much aux and is inefficient....... Then the new owner tells his friends and neighbors....

I have thought about this previously, mainly because a poster here designed their heating load around a thermostat set point in the low 60's (F).  I assume any future selling price for their house will need to be adjusted to compensate for the work needed to reach a higher set point (without lots of aux usage.)

Pros, what thermostat set points for heating and cooling do you design for?

70 and 75 always.