hi all! i will post this here since i know that people lookin in the GEO forum are probably the most inclined toward hvac material. I am currently building my next house. ICF construction, 8"concrete walls with 2"/2" EPS on each side We are up to the roof, so i need to start planning my winter time/moves. I have already installed 2000' of pex ( yes o2 barr ) in fron of the house, in a 6ft deep, 35'wide, 100' long trench should be in water most of the year ... All of the heating will be done with electrical heating floors ( electrical is ok cheap here, enough to overcome other sources with its simplicity of control and installation ) in all and every floors of the house ( yes even the garage ) I want to use the geothermal pex loop for AC during the summer months ..we don't need much ac here ( Quebec center ) all floors are concrete over steel deck, 4-5" thick concrete with a 0.5"dense EPS foam under them approx 1600sq.ft each floor. times 3

Now that this is said,
what i need help on is the complete HVAC and it's control/features

i will install a very good/big air exchanger ( recommend Venmar brand ? they are local ..some good options )

Would like to have complete independent control over heating and cooling of each room in the house
( 3 bedrooms, 2 bathrooms, 1 open kitchen/living/entrance, garage, Home theater, training room and a work place )

I want to DIY everything, i have no budget and no patience for "pros" in my stuff...done all the
house alone up to now ( 40' high of ICF blocks !! ) and will continue that way.

I have checked on a few 4" inline fans, and controls ... but i have too many ideas at a time,
and it is hard for me to determine the best layout or even plan possibilities.

Would like to have help on how to start, basics , requirements ...
all advices are welcome and will be read with attention! :)

i have no fixed budget, could go up high if it does all that is required/wanted

If you insist on very small single room zones, the only way to make that happen is with an indirect water based system. Present day residential air systems don't have enough turn-down in their capacity control to effectively serve very small zones. You would use one or more compressor units to heat or cool water in insulated storage tanks and then each room gets a thermostatically controlled blower / coil unit working off water from the central plant.

Expensive and unconventional in a typical home? Yes.

Alternatively, carefully group some of those rooms into moderate sized zones, buy a two stage central system, add in a bypass or barometric dump damper and thereby have a more conventional system.

I have also read about radiant cooling systems , obviously they do nothing for dehumidification , or air filtration , but in Canada the limitations of these systems might not be an issue , also could utilize the geo radiant ( wall and ceiling ) as first stage heating

Just another thought

thanks for quick answers ..

what exactly would buying a 2 stage unit bring me in terms of control ?

i can regroup "some" of the zones..but that would be a compromise

Then heating is already 100% autonomus in each an every room
and is already covered by independent thermostats for the electrical in concrete floor heating
no need to use any other method, as this will never be matched in terms of control
with anything else... though i'll still need to move the air around during winter
wich is a seperate thing

i don't have any problems with having to control 15 different inline fans if the need is there ..
in fact i don't have a limit of complexity if it is required and will have a benefit.

if we move forward,
would having seperate inline fans for every zone be a good idea?
at first i thought about making fan connections to main air source that could be inverted
to change flow directiong for heating vs cooling

i would also like to use ceiling air dispersers ( inputs in zones .. ) as the cool air
should spreak more efficiently starting from the ceiling ???

i have 2ft or more of space between the ceiling and the adjacent floor on every floor
with open web steel joists ..so alot of space to install alot of tubing..as necessary

What would be the optimal setup ?
i don't see why the water option couldn't be used,
but i wonder what kind of problem, cooling will bring with such system,
and there will be alot of water to collect at every point, VS a central coolin
radiator connected to the geo system ...
could have varying "traps" in the pipes that would vary the amount of cooled air
each room would received VS the amount of recycled all zones air ???

I also have a 15' by 15' room that serves as the roof exit ( terrace on flat roof )
wich is well the highest point of the house and is connected to both the first floor main room,
and the second floor central corridor
it features 3 windows with good SHG
as i thought about using this place to "collect" heated air
and push it back throuhg the system, or send it in the basement ?



on another note, i want to install a big greenhouse on the roof ..probably 15' by 25'
i thought about using the humid air from both bathrooms after/while bathing/shower
and send it in the greenhouse to get both benefits..
do you believe it is a good idea?
could help maintain a good temp during winter time??
but i wonder about the effect vs the heat exchanger unit ...

What you describe is sufficiently outside typical residential systems that I don't feel able to offer effective advice over the internet, so I'm going to stop trying. What you describe may ultimately work very well but will need very specific and careful design work based on your project's unique attributes.

The laws of physics are strictly enforced, and the principles of ACCA Manuals J, D, S, and T always obtain.

What Im about to recomend will likely get me banned from this site
There is a product made for what you want
Mistsubishi P series citi multi unit
over 40 zones off of a single unit . prepare to drop some cash but its what you want, does offer heating non optional ( good back up )
Sorry guys geo is still the best but with the controll requirements of this guy its the only solution thats reasonable

Agreed. Another brand that may have the same multi small zone control is Daikin...also high $

Question: In the future when residential GSHP may have variable speed compressors, will this allow zoning from room to room?

Do variable speed compressors ramping up slowly? If so this would eliminate the initial high current draw and flickering lights current compressor experience when it kicks in. Low startup current draw would also make it generator friendly.

I could also have a second electrical circuit entry installed only for this ... i currently have a 600A 240V input ..will probably be enough for now i will look into those multi units to see how they work ...thanks for the ideas :) keep em comin' :p

ok i see,
those are systems comprised of controls and programs
and independant cooling/heating units through wich the air passes
so each zone as its properly sized unit.

but that doesn't resolve much more than using independent induct air fans with proper controls
and a central air mix chamber
since i do already have heated floors
and i'd like to use cooling from the GEO source
not a compressor ..no point

i have not much problem with finding HOW to make things work
what i need help from you guys i understanding the basics,
pointing the requirements and guiding so i do not make errors

the basic design of the system is where my mind is currently stalled on
should i use a central mixing air chamber?
inline individual fans or not ? in service room or near each zone ?
how to positions inlets and outlets for cooling vs heating ?
what kind of control is possible ?
heating is easy to control with regular thermos,
could always lean toward Z-wave or computer remote controlled
thermos later ..
but cooling and air flow ..now that's something else

ACCA Manuals J, D, S, and T cover all these topics.