Hi All,

I'm in the planning stages of building a new timber frame in Northern Michigan (lower pennisula).

This vacation home will be a cape style 28' x 34' with drive in garage below main level and 600 sq. ft. second floor.  I'll be harvesting timber on site and hiring a local sawyer to rough cut beams, floor and exterior siding.

I'm planning on 6" SIP walls and 10" SIP roof and ICF garage below main level.

We'll need to have a well drilled for water, so I'm looking into the possibility of a pump and dump water to water geothermal for hydronic radiant heat.  I've expressed my concern regarding water quality with a geo dealer in the area and he says they're very common in this area.  I plan on having water testing done to confirm this when the time comes, but for now assuming an open loop is doable.

Would like to heat garage/mechanical room with hydronic radiant in the concrete slab and main level as well.  My initial desire is to use 1.5" thick hardwood flooring for upper level, which will also provide ceiling in lower level.   This will prohibit use of radiant heat in floor on second level.  Because me and my wife are creatures of comfort, air conditioning is desired.

I would like to hear opinions on the possibility of using fan coils to cool the main area and fan coils to heat and cool the upper level.  Anyone have experience using fan coils with water to water geo?  Good, bad idea?

I prefer hydronic radiant heat rather than a ducted air system, but if this idea is silly, then a water to air will be considered.

I welcome all comments!

Bub

Posted By Bub on 23 Feb 2010 10:28 AM
Hi All,

I'm in the planning stages of building a new timber frame in Northern Michigan (lower pennisula).

This vacation home will be a cape style 28' x 34' with drive in garage below main level and 600 sq. ft. second floor.  I'll be harvesting timber on site and hiring a local sawyer to rough cut beams, floor and exterior siding.

I'm planning on 6" SIP walls and 10" SIP roof and ICF garage below main level.

We'll need to have a well drilled for water, so I'm looking into the possibility of a pump and dump water to water geothermal for hydronic radiant heat.  I've expressed my concern regarding water quality with a geo dealer in the area and he says they're very common in this area.  I plan on having water testing done to confirm this when the time comes, but for now assuming an open loop is doable.

Would like to heat garage/mechanical room with hydronic radiant in the concrete slab and main level as well.  My initial desire is to use 1.5" thick hardwood flooring for upper level, which will also provide ceiling in lower level.   This will prohibit use of radiant heat in floor on second level.  Because me and my wife are creatures of comfort, air conditioning is desired.

I would like to hear opinions on the possibility of using fan coils to cool the main area and fan coils to heat and cool the upper level.  Anyone have experience using fan coils with water to water geo?  Good, bad idea?

I prefer hydronic radiant heat rather than a ducted air system, but if this idea is silly, then a water to air will be considered.

I welcome all comments!

Bub

what you are considering is common practice in the geothermal  arena

Radiant for second floor could be handled with panels or in the wall or ceiling.
Open loop is still the most common heat pump in MI.
Make sure your installer has done lots of geo, I know one in Traverse City that was recommending against until 2 years ago, now he's all about geo. Lots of carpet baggers with limited experience out there.
Look us up if you need another opinion.
Good Luck,
Joe

Thanks for the input Joe.  Where are you located?  Can you give me your company name in this forum?

I plan to research the subject as much as possible, but when it comes to sizing and designing system, I'll need help.

As an alternate to using a water to water geothermal system for hydronic radiant heat, I'll also consider using old fashion baseboard electric heat.  Since I'll be paying a premium for SIP walls and roof, I shouldn't need much heat.  Preliminary estimate of 25,000 BTU to heat home. 

Downside to electric baseboard is air conditioning and domestic water will need to be addressed separately whereas geo could link these systems together.

Since I need to drill a well for domestic water anyway and open loop seems plausible, I'm leaning toward geo. 

This is a great forum to gather information and educate oneself.  The geo survival kit was the single most beneficial article I've read.

Bub

If you are within his combat radius, go with Joe.

You say you want AC - that'll require ductwork. You have very low loads, so let the AC ductwork supply heat as well.

OTOH I''m not totally sure the 1.5" hardwood rules out radiant upstairs - very low heating loads can be met by radiant under adverse conditions in a very well insulated house which you describe. That and second floors get heat from lower floor, reducing load even more.

I live in FL, but if I was building a dream home north of I-40, I'd want as much radiant as possible.

This week I'm on assignment in Chicago and feel constantly cold - if my hotel room had radiant floors I'd be a much happier camper...

I'm in Howell and you are welcome to PM me. Not sure where you are, our getaway property is on Lake Huron. If you are Traverse way I have an associate over there.
With an extremely low heat load, geo is not always ideal depending on other usage ie if it is a summer home only and you rarely need 70* in the winter etc.
Part of the bid process should include operating cost calculations where you can compare different sources of heat vs ROI.
Good Luck,
Joe

Engineer: I want radiant heat in floor and air conditioning and trying to determine the best method to accomplish this. 

From what I understand, running chilled water through the in floor tubing for cooling is a no no, especially with hardwood floors.  That's why I asked about using fan coil units for summer cooling.  I would really like to avoid running ductwork if at all possible, but if I have to, then the radiant floor heating is out and I would get a water to air geo.

Chicago in the winter is no fun!  Stay warm.


Joe: The cabin will be overlooking Lake Charlevoix.  Initially, I foresee use primarily being in the summer with occasional trips in the winter, but as always, things can change and I think it best to design for permanent year round occupation.  That's my thinking today, subject to change of course.

I'm also considering alternative energy for power.  If the cabin is designed and constructed for low energy requirements, a solar array, windmill or both could be a fun consideration.  ROI is not always measured in dollars, there is value in self reliance.  At some point, I'll need to put a number on it, but for now I'm dreaming big.

Mechanical system decisions are at least a year away.  Right now I'm finalizing the site plan with the surveyor.  By summer I would like to have the timber frame designer selected and plans drawn up.  In the mean time only campfires and high hopes.

Thanks for the input.  It really helps to write some of these things down.  It makes me think.

Bub

 

Unless floor plan is extremely open, there is little chance that you can get away with out ducts. You could go with something like a hotel console unit in every room, but you may not like the appearence or price tag.
j

An air source heat pump with electric aux heat may be more cost effective for your application.

I think I need to get the architectural drawings done so I have something to show the HVAC guys.

Seems like I've put the proverbial cart before the horse.

Joe, when I'm ready, I'll get a hold of you.

Bub

I would look to supplement your radiant/geo with a Unico high velocity unit.
With your super tight SIP/ICF dwelling, HRV is required and would be integrated into the Unico solving the AC, 2nd floor radiant, and HRV hurdle.
Very comfortably, I might add.
Jim

High velocity duct systems impose some cost and efficiency penalties that would seem to be avoidable in new construction.

That said, if you are truly allergic for whatever reason to conventional ductwork, high velocity may be a reasonable alternative.