Rant of the day: Thermostats

[Cybrvanr]

I'm probably one of the odd guys out that actually likes things a bit on the warm side. I attribute it to my small size, and lack of insulation I guess...I'm not much larger than most gals! I usually end up just layering up in clothes during the wintertime because anything under 70 is chilly to me. During the summer, it's a bit more tricky, since I'll dress to keep cool outside when I'm running serivce calls, but then I get chilly inside the offices.

One factor that comes into play too is that sedentary people feel cooler than active people. We ended up having to get separate HVAC units in our shop between the office areas, and the build areas because of this simple fact. The office people sitting around all day like it a bit warmer than we do, moving, lifting, walking and being physically active building A/V systems.

At least I'm not like most women, where their internal thermostats change on a minute by minute basis!

 

[petek]

I wonder if Venus, Laundress, BrneyedGrls and Bethanns thermostats will be rising after they read the above posts hahahahaha

 

[jasonl]

That whole line of thermostats have been on the blink since Eve.

(ducks and runs)

 

[toggleswitch]

ooooh child, it's getting HOT in here........

and LUCKY LUCKY you, you have the proper device attached to your tool-stash to internally adjust that model, and keep it purring beautifully.

 

[scott55405]

Here's a poll for those with central air, especially those in humid areas--how many folks, when running theirs, keep the furance fan in the "locked on" position? My father has always done this, as I have when living in a place with central air. IMHO, having the whole thing shut down except when the thermostat activates it makes for a very stuffy residence that can tend a tad too warm between cycles. The fan running keeps things much more even.

 

[toggleswitch]

oh yes a constant-running fan keeps statification (floor to ceiling temp differences) to a minimum.

In my case the TRANE brand unit I had installed *REWARDS* me with a 220v evaporator fan(indoor portion of centail-air unit)- what a PITA that is. [There is no reason to do that on 220v].

It also runs the indoor fan for two minutes after the system shuts down to *salvage* the last few drops of cooling effect. This helps pull humidty off the coil. Which is good & bad.

Good- Less chance of mold and smell if the coil stays dry.
Bad- The ambient humdity in the house goes UP unnecessarily.

I should have considered a better unit (higher end TRANE) with variable speed fans on the indoor AND outdoor units.
I was stupidly talked out of the untis that have TWO variable speed compressors and EER's of 20.0 +/-. They say in my climate the addtional cost is not worth the enegry savings realized. HA!

http://www.trane.com/Residential/Products/AirConditioners/Compare.aspx

 

[toggleswitch]

EER= Energy Efficiency Ratio

BTU's moved per Watt.
Heat moved per unit of electricity.
Where BTU- British Thermal Unit.

And off on another tanget- FYI: Rules of thumb. In most parts of this country:

10 watts of heating is required per square foot of floor area.
1 watt of heating is required per cubic foor of floor area.

12 foot x 12 foot room = 144 square feet at 10 watts /sq. ft.= 1,440, therefore a 1,500 watt heater would suffice.

[The same room size is 3.6 x 3.6 meters or 13+/- square meters]

http://www.friedrich.com/faq/question04.asp

 

[toggleswitch]

Sorry:

The ex- number cruncher in me still *comes-out*

 

[wiskybill]

Toggle, you are so wise it's scary. I've learned some new things today. And if my "ex" had been a number cruncher, he might still be in the picture.

You are so right about stratification. I had a split-level home before this apartment. 3-level heating and cooling was always a challenge, especially the cooling. The upstairs bedrooms were always too warm when the rest of the house was comfortable. Fortunately the master br was on the main level. I always kept the blower on 24/7 for heating and cooling.

Now, my apartment is total electric with baseboard heat with a wall unit for air conditioning. Don't need the air very often so it's not really an issue. The challenge here was balancing the 4 thermostats. Once I got them set to maintain 68 degrees I never touched them again. I turn off the breakers for the heat, each baseboard has it's own, when spring comes.

Thanks for the info.

 

[toggleswitch]

 

[toggleswitch]

Bill:

We'll have to chat offline about the joys of downgrading living space in exchange for casting off dead-wood (parden the pun).

My house is soon to be on the market and the ex and I are temporarily room-mates. JOY! (no one is dead yet)

HA!

 

[toggleswitch]

Well, if the glass slipper fits, honey...

.....and VERY VERY soon my prince charming will come snatch me up.

 

[48bencix]

Keep fan running

I keep my t-stat on auto fan, which shuts the blower off when not heating. The blower in my central uses about 800 watts, at $.10/kwh that would be $1.92 per day.

Since I have a 100,000 btu furnace, about a therm, which is about $1.70 right now, that's $1.70 plus $.08 for the fan per hour ($1.78) So when I think how cold I am, I think about that cost. Right now it is quite mild here in Sacramento, around 45 degrees at night, so I'm using around 2 therms a day to keep the house around 63 when I am there and awake, 58 at night and OFF when I am not there. I like OFF and that's why I do not have a programmable t-stat.

When and if it gets colder it's going to be close to $4.00 to heat the house each day. (1800 sq. ft. pretty good insulation, but single pane windows with window coverings)

I have found that the best way to deal with a partner that uses t-stats illogically, just let him, it's a small thing. Your life will be much more pleasant than trying to change someone. This technique works for many situations, I have found in my older years.

 

[DADoES]

I set the blower on auto 99.9% of the time. The 0.1%, which I should perhaps do more often, is when heating, which helps keep the temp a bit more equalized in the master bedroom and bath.

I once had a White-Rodgers programmable 'stat that allowed setting the blower for on/auto for each period.

 

[Cybrvanr]

We can pull that out a little bit further by converting the wattage to BTU's. It takes .3 watts to make 1 BTU, so if your room takes 1,440 watts to heat it, that means it requires 4800 BTU's to heat it. A regular "plug-in" heater should suffice in this room. This is a good "ballpark" figure, but there is much more involved in calculating heat requirements.

This math, or course takes into account the room being properly insulated. There are many other factors determining the needed heat too, such as how many of the walls are exterior, and their surface area, what floor in the building the space is in, and of course, the proper distribution of the heat. Human bodies tend to be more comfortable with the heat at their feet (which is why baseboard and radiant floor heat feels so good!). What you guys are talking about using the blower for stratification will allow you to also operate the system at a lower setting if the heat within the room is properly distributed.

There's not much hope for my house. The vents are in the ceiling, which works great for AC, but it's terrible for heat. The ceiling will be 80 degrees, and the floors about 65 degrees! In the middle, 72 degrees at about the thermostat's level on the wall. Running the ceiling fans help a little, but really only makes the room drafty

 

[DADoES]

Mine are also in the ceiling. In this area, it's rare for them to be anywhere else unless one lives in a trailer house. Of course, cooling is priority on the TX coast.

 

[jasonl]

Fan set on auto

I have my fan set on auto because in the summer after the compressor shuts off the fan's just blowing warm humid air. We have an Amana system here and the fan will run for about 2 minutes after the comp has shut off to get the most out of the evaporator.

When I lived up north Bri's parents had the system fan on constantly and it worked fine.

Of course, window units are a different matter, they're ON no matter what (unless it's an Energy Star model with automatic fan).

 

[toggleswitch]

Cool.

I know it as 3.4 BTU per watt!

 

[toggleswitch]

Said: There's not much hope for my house. The vents are in the ceiling, which works great for AC, but it's terrible for heat.

Odd that in VA the supply air ducts and vents are in the ceiling as, in IMHO, the heating requirement is perhaps greater than the need for cooling.

One way to ensure comfort IMHO is to place the return-air vent [the one(s) that suck(s) in] nearest to or IN the floor.

Often-times there are two centrally located return vents (if not a system that has one in each room); one near the floor one near the ceiling. Simply close the damper the UPPER one in winter. Make sure the system still has an air-supply, of course. If the upper grille/register does not have a damper you may want to replace it with one that does, or make a SS or equivalent sheet-metal cover for the top one.

It will make a huge difference in comfort.

let us know.........

 

[gregm]

fan

My experience when living in FL is that during the peak summer, you had to run the fan (in central AC systems) MOST if not all of the time otherwise mold/mildew would build up inside the ductwork and on the condensor, it was nasty, but running the fan all the time got rid of the smell. I moved out of there, thinking if you can actually smell mold, that can't be a good thing to breathe and it sure is an awful smell.