manual J load calcs - ICF geothermal passive solar

[v8z]

I have a few questions for those in the trade:

1: Does the current Manual J 8th edition include considerations, calculations, and/or values for the infiltration tightness of an ICF building envelope? Does it utilize both u-factor and shgc for windows?

If so, can it be adjusted to address passive solar gain for structures designed with proper southern orientation and overhangs?

The windows and doors for the home have Energy star rated u-factor and shgc, but the shgc is being spec'd high for thermal gain in the winter, with the windows shaded by building overhangs in the summer ( northern climate zone).

I only received one of several bids requested so far, and the contractor said he did the load calculations per manual J. But he sort of tap-danced around specific questions about the calculations, and the unit size/btu rating seems to me to fit a "sq.ftg./8" sizing, as opposed to an accurate calculation based on r-22 ICF walls and r-40 ceilings combined with geothermal and radiant/gyp. floors.

1. I've identified the WaterFurnace brand gshp's as the most efficient, and have requested the bids accordingly. This contractor spec'd a Synergy3 unit with radiant /forced air htg/ac with a 15kw boiler. When I asked him about why the Synergy instead of a reversible EW unit, he said forced that water coil ac air-handlers were hard to find and the boiler was for backup. I'm not sure how the boiler is backup, since its an all electric home.........

I'm hoping that the other contractors bidding will be more specific/ forthcoming with information on how they arrived at their specs, but in the meantime,

Can those with experience of combining geothermal / radiant / ac / ERV comment on their approach and equipment choices?

Thanks in advance.

[Al Moran]

Yep, I have a comment...Do your own f****ng homework.

[Bubba]

You are just too damn funny, buddy. You want all the calc's and all the answers.....................For Free! Then you can get you and your buddy to do it on the side over a case or two of beer. Hit the road. Bubba

[v8z]

Actually, I'm a homeowner who's trying to find a contractor that knows his ass form a hole in the ground.

I'm not asking for the calcs themselves, just trying to find out if the manual J method has enough information to allow a HVAC contractor to determine load values for a house constructed using modern technology materials, passive solar, etc. or if I'm going to have to pay an energy consultant to spec those loads.

From your debasing answer, I'd guess you're a guy who works a wrench with his butt crack showing, rather than one who uses a laptop and his mind.

[Bubba]

.........and you're a whinning homemoaner who didnt get what he wanted for free. Guess what, slim? I know how to use Manual J ..........7th edition, ..even that data clogged POS 8th edition. Guess what else, slim? You DONT! Sucks to be as stupid as you, eh? Now get you debasing nose out of my butt crack. Open your wallet you skin flint. "Pay the man". Bubba

[v8z]

Let me add that this will be a contracted system with a budgeted number over

25k, in Ohio, where installation of a conventional, high-quality forced-air system goes approx. 8-10k.

In the questions below, I'm trying to determine if manual J alone works for the type of home being built, and if some contractors who have experience actually installing this type of system can comment on their preferences of general equipment types - not specific brands or model - to aid us in evaluating the bids we receive.

[Bubba]

[John Smith]

You can have 3 mechanical engineers figure the calculations and have 3 different answers. You really need do some searching and find someone who can help you, start with the manufacturer's of the equipment you want installed, they should be able to point you in the right direction.