Solar House questions

jerrye · 10-23-11, 11:39 AM

I'm in the process of starting to build a house in Colon Mexico about 50 miles fSouth West of Queretaro Mexico.
Elevation 7000ft
Lat 20.6 N
Lon 100.2 W
95 degrees on mid summer days
25 degrees winter nights

There is a small pond 100 ft x 300 ft next to the house that is used to cool the thermal well water for irrigation. I plan to use this water with PEx tubing in the slab to cool the house and install heat collectors on the roof to heat the house.
Normal day in the winter is 25-35 degree night then its 70 degrees at 10 am,
then around 2 pm it starts to cool off again
Changing from night time heating to daytime cooling with PEX tubing in the concrete slab I think would be around 2 to 3 hrs.
I was wondering if maybee I should have a seperate systems for heating and cooling.
Use PEX in the slab for one system
Use water to air heat exchangers for the other system
Any ideas would be greatly appreciated.
The area is very remote rual area with high cost for electricity, so passive solar is the only option I have.
Still trying to figure out what roof eve overhang I need

GaryGary · 10-23-11, 08:12 PM

Hi,
It sounds like a good climate for a home with quite a bit of thermal mass. That is, you have large temperature swings, but they go both above and below a comfortable temperature. With a lot of thermal mass, the house inside temps won't swing through such big ranges.

In the summer, if the nights cool way down, you can ventilate at night to cool the house mass down, and if the house is built to minimize heat gain during the day, the nigh ventilation and mass may be all you need to keep the day temperatures comfortable. It will depend to some degree on humidity levels.

Using pex in the floor for cooling will be limited by not letting the floor get down to the dew point to avoid condensation.

Gary

10-23-11, 11:39 AM	#1
jerrye Lurking Renovator Join Date: Oct 2011 Location: Spring branch Tx Posts: 6 Thanks: 0 Thanked 0 Times in 0 Posts	Solar House questions I'm in the process of starting to build a house in Colon Mexico about 50 miles fSouth West of Queretaro Mexico. Elevation 7000ft Lat 20.6 N Lon 100.2 W 95 degrees on mid summer days 25 degrees winter nights There is a small pond 100 ft x 300 ft next to the house that is used to cool the thermal well water for irrigation. I plan to use this water with PEx tubing in the slab to cool the house and install heat collectors on the roof to heat the house. Normal day in the winter is 25-35 degree night then its 70 degrees at 10 am, then around 2 pm it starts to cool off again Changing from night time heating to daytime cooling with PEX tubing in the concrete slab I think would be around 2 to 3 hrs. I was wondering if maybee I should have a seperate systems for heating and cooling. Use PEX in the slab for one system Use water to air heat exchangers for the other system Any ideas would be greatly appreciated. The area is very remote rual area with high cost for electricity, so passive solar is the only option I have. Still trying to figure out what roof eve overhang I need

10-23-11, 08:12 PM	#2
GaryGary Apprentice EcoRenovator Join Date: Nov 2008 Location: SW Montana Posts: 139 Thanks: 1 Thanked 21 Times in 15 Posts	Hi, It sounds like a good climate for a home with quite a bit of thermal mass. That is, you have large temperature swings, but they go both above and below a comfortable temperature. With a lot of thermal mass, the house inside temps won't swing through such big ranges. In the summer, if the nights cool way down, you can ventilate at night to cool the house mass down, and if the house is built to minimize heat gain during the day, the nigh ventilation and mass may be all you need to keep the day temperatures comfortable. It will depend to some degree on humidity levels. Using pex in the floor for cooling will be limited by not letting the floor get down to the dew point to avoid condensation. Gary