Heated Garage and Humidity

[North Idaho Wolfman]

Wolfman if heat the drive way you won't have a reason to use kubota all winter [emoji853]

Oh no chance of that, I have 1/4 mile long driveway.

Wolfman, my boss built his retirement home in 2000. He said he tried to think of everything. It ended up really nice and he was just 60. Double wide hallways for 2 wheelchairs, extra wide doors, laundry at both ends of the house, 2 dishwashers, tile floors thru out, 2 boilers for floor heat, 2 a/c units, whole house generator, ..... also heated his rear/front sidewalks and the front driveway. He had 2 sensors, 1 for moisture and 1 for temperature. It would snow and melt the driveway. After the first winter month and the wife got the energy bill(over $1k)
needless to say she said to never turn the outside heat on again, that was in 2001

I've looked into the whole system, the tank less boilers increase efficiency 100 fold. You can run this system on electric, but it's not efficient enough, propane or natural gas is the way to go.
Or if your making your own pellets, pellet boiler.
But yes overuse of the driveway, sidewalk heater would waste a ton of money! I'll mainly use it when it ices over too much for a normal scraping off.

Wolfman, what are you going with for AC? I'm thinking ductless for mine. Current plan is stained concrete on most of the house, epoxy in the mechanical room. Oversize the mechanical room to make room for a chest freezer and a small reloading bench. At least one bathroom will get the tall toilet, a shower with a bench, and room to move a walker or wheelchair. Open design between kitchen and living/dining room. Pedestal fireplace as close to the majority of the plumbing as it will fit without looking stupid.

We don't get very hot here, lucky if we hit 90 a day or two over the summer.
2 systems, geothermal exchange will cool the floor and a secondary heat pump that heats and cools the floor (the heat aspect will probably never be used).
The heat pump should be rarely run as I believe the geothermal will do the trick.
All it involves is trenching a run of some pipes about 6 foot into the ground, then sending the water threw that loop in the summer.
Still doing the last of the research on that part.

A few notes: If your going to have a big chest freezer figure it's location and do not put any pipes in the slab under it, also no pipes under cabinets, toilet, or bathtub.
But you can double up under a shower floor if you are doing a mud pan and tile shower floor (makes for a nice warm floor in the winter and cool floor in the summer).
Also check the epoxy and make sure it doesn't have an R value more than 2, some thick epoxies do and it will cause some serious exchange rate issues.

 

[Grouse Feathers]

We don't get very hot here, lucky if we hit 90 a day or two over the summer.
2 systems, geothermal exchange will cool the floor and a secondary heat pump that heats and cools the floor (the heat aspect will probably never be used).
The heat pump should be rarely run as I believe the geothermal will do the trick.

You don't expect a condensation problem with cooling the floor?
The heat pump for heating the floor should be able to beat propane and maybe natural gas or pellets depending on your source.

 

[North Idaho Wolfman]

You limit how cool the floor is and as long as you keep it above the dew point no condensation can form.
The other option is to add a dehumidifier to drop the dew point.

 

[tthorkil]

I have a geothermal system that was installed in 2013 and it not only heats the methane/water fluid for the floor but also provides forced-air AC using the same system. It also provides forced air for heating so when the heated floor lets the air temperature in the house drop below the thermostat setting when it gets well below zero outside it can quickly warm up the inside. The floor heat takes a while to recover to overcome drastic changes in outside temperatures. My geothermal system has a refrigerant compressor that uses the ground loop to provide either heat or cooling. I try to have my floor temp set such that the forced air system comes on a couple of times a day to prevent ‘stale’ air. I also occasionally set the humidistat below the current humidity level just to get fresh air in the house when it is too cold to keep the windows open.

 

[bucktail]

I don't think that the floor cooling will work here. Air conditioning here is for humidity reduction as much as it is for cooling. As an added bonus, I'm planning on doing a berm home. The back wall will be buried to just below the bottom of the windows. It should help with heating and cooling, but the humidity will be worse.

I should probably get it bid with and without geothermal. My internet research on geothermal indicates that horizontal loops don't work in sandy soil, which I have, so I would need to go vertical.

 

[tthorkil]

My surface soil is also very sandy – what it is like 10 feet down I do not know as I was not there for the excavation and burial. My geothermal system has been performing well. This is an excerpt from the contract:
5-Ton GeoComfort Combination Forced air and Hydronic
Geothermal System GCT060 installed. This system includes a 5-Ton
HORIZONTAL (not wells) loopfield consisting of 5-800' loops for a total of
4,000 feet of pipe installed in the ground 10' deep. , does NOT include any
duct work or hydronics.
This system is ***420% efficient on first stage heating and 380% efficient in
second stage heating. This unit is equipped with a 10 kW Electric Plenum
Heater for emergency heat or supplemental heat in very cold temperatures
(Requires an additional 60 amp circuit)
*** These efficiencies mean this geothermal system will operate for approx.
1/4 of the kilowatts than electric heat.
*This unit is equipped with a Desuperheater that will heat approximately
2/3rds of your domestic hot water at 300% efficiency
Extra 800' Loop for more capacity during a long cold winter, also makes
units run more efficient by providing warmer incoming loopfield
temperature than rated.
Floor heat system including(1) oxygen barrier tubing, (2) 2" 250PSI
polystyrene insulation under slab, (3) manifolds, (4) pumps, (5) Single
RANCO aquastat to control geothermal hydronic water temp, (6) buffer
tank, (7) staples, (8) labor, (9) antifreeze, (10) thermostat to control floor
and (11) piping to and from geothermal unit as add on to Geothermal
system. ***Concrete contractor is responsible for insulation around
perimeter*** ***This Proposal does NOT include final grading of sand.
Sand fill needs to be final graded BEFORE we arrive at jobsite.
Air Exchanger ... SummerAire 130 Air Exchanger HRV (heat recovery ventilator) Run by
humidistat
Duct system for 5- Ton Geothermal Forced air Unit Installed in the attic.
Round with insulation. Must also cover with blow in insulation.

 

[OldeEnglish]

How's your electric bill with the GEO?

 

[MattN03]

With the garage well insulated maintaining the garage and workshop at 50F (65F in the workshop for days or weeks at a time for projects) I use about ½ of a 500 gallon tank of propane

Is this all winter that you use 250 gallons?

 

[Grouse Feathers]

Is this all winter that you use 250 gallons?

Yes about 200 to 250 gallons of propane all winter for heating the garage, plus in the house for cooking and drying clothes.

 

[Bulldog777]

There is some geothermal info on the internet/YouTube that is very informative. Soil type is important due to heat transfer. I've worked on geo units and done repairs on the geo lines(fusion). In Central Texas, the soil would expand and contract leaving air gaps, thus no heat transfer. I have seen people put horizontal lines and run their septic sprinklers over that area to keep it moist and compacted (sandy,loam soil). In other applications there were vertical wells at an average of 300' deep, one well per ton of AC. This was the expensive part,drilling. But these units are very efficient, especially AC.
As mentioned earlier in the thread, dew point is the determining factor. Keeping the temp in the "sweet spot" can prevent a lot of it, but conditions vary from area to area. Concrete is porous, if you have a crawl space underneath the slab and condition above, it can condensate below and wick up through the slab if the crawl space is not properly vented. (Had a building that the floor tile kept coming up, crawl space had no ventilation and concrete had condensate all over it. The condensate was causing the adhesive to release)
Hydronics is awesome if installed correctly. I set up a commercial freezer that a company put in hydronic heating in the slab and at -15*, we had no slab problems or condensate issues. This was a 2700SF freezer.
I can't speak on a lot of humidity issues in the North, but dew point is the key.
Once you drop below dew point, you will condensate. Of course bringing snow into the space will increase the humidity, but I doubt momma is going to park outside the garage.....

 

[bucktail]

What I've been reading pretty much lines up with bulldog. The coils will cook off the moisture in sandy soil in the summer when you're using it for cooling.

Tthorkil, do you know if they made your loops with trenches or horizontal drilling? If they dug them in, they may have put in a little clay around the pipes to help with heat transfer. The installs I've watched on youtube and TOH they've just horizontal drilled under the house.

 

[tthorkil]

What I've been reading pretty much lines up with bulldog. The coils will cook off the moisture in sandy soil in the summer when you're using it for cooling.

Tthorkil, do you know if they made your loops with trenches or horizontal drilling? If they dug them in, they may have put in a little clay around the pipes to help with heat transfer. The installs I've watched on youtube and TOH they've just horizontal drilled under the house.

The pipes were trenched -

 

[tthorkil]

How's your electric bill with the GEO?

All of my heating including the water heater is on Off-Peak(O.P.) meter. The garage is 30' x 40' floor heat only kept at floor temp of 50-55 Fahrenheit and the house is 30' x 50' floor heat & forced air(AC & heat) floor heat is set to 70-75 depending on outside temp with thermostat for air temp set to 66. I vary the floor temp to have the forced air kick in a few times per day.
January 2017 O.P. 1 1259 X .07400/kWh $93.17
Jan - Mar has been 700 to 1260 kwh/Month and Jun - Aug has been 100 to 150 kwh/month.

 

[North Idaho Wolfman]

Did they roll out the balls of pipe , or were they buried like that?

 

[tthorkil]

If you look closely at how the rolls are prepared you will see that they are zip-tied in loops rolled together. I was not here when they installed them but I would guess that by the looks of the rolls that they rolled them out with the loops left intact. The area that was excavated was quite large - I would guess that it was at least 50' wide x 50' long x 10'deep.

 

[Bulldog777]

If I was guessing by looking at the pic, they unrolled those balls with the loops laid out overlapping each other some. Surface area is what you are after, more surface area...more heat transfer. The trench was probably slightly wider than the ball of pipe.

Sent from my SPH-L720 using Tapatalk

 

[tthorkil]

The trench was at least 50' wide x 50' long x 10'deep. The pictures are of the pipe in the bottom of the trench.

 

[OldeEnglish]

All of my heating including the water heater is on Off-Peak(O.P.) meter. The garage is 30' x 40' floor heat only kept at floor temp of 50-55 Fahrenheit and the house is 30' x 50' floor heat & forced air(AC & heat) floor heat is set to 70-75 depending on outside temp with thermostat for air temp set to 66. I vary the floor temp to have the forced air kick in a few times per day.
January 2017 O.P. 1 1259 X .07400/kWh $93.17
Jan - Mar has been 700 to 1260 kwh/Month and Jun - Aug has been 100 to 150 kwh/month.

Your rates are pretty low! The biggest complaint I've heard about GEO thermal is the electric bill. It's a good concept and works well but can get very pricey. The selling point of if a few years ago was the tax benefits. If I remember correctly it was something like 20% rebate on anything hooked to the GEO. It worked out well for high end homes that had like sub zero fridges, radiant, forced air with AC, heated pools, hot tubs, and so on. It worked out for them that it would have cost them more to have the same things without the GEO. I don't know if those rebates are still available.

 

[Bulldog777]

The trench was at least 50' wide x 50' long x 10'deep. The pictures are of the pipe in the bottom of the trench.

Then they made a well bed. Rolled them out next to each other, connected them and probably had one ditch back to the house. I've worked on some before the loops were in ponds, one with a fountain in the pond.