Heating for $2.32 a day ($66.70 per mo)

Xringer · 11-23-11, 07:04 PM

Using two Sanyo ASHP systems running simultaneously. Sanyo in Stereo?

Max heating cap @ 36,000 BTUh x2 is 6 tons.

http://i46.photobucket.com/albums/f1.../NCL/meter.jpg
http://i46.photobucket.com/albums/f1...0slot/R072.jpg

1240 sq ft. http://i46.photobucket.com/albums/f1.../9784_9784.jpg

310 kWh used during the last 30 days. (They read the meter today).
$2.23 a day @ 21.6 cents a kWh x 10.333 kWh per day.

That's like a 430 watt load left turned on 24-7. (Our Plasma TV!)

This year, heating cost is going to almost double my bill !!

Here's the weather info:

Climatological Data

------High:------Low:------ Average:
Temperature: 69 °F 24 °F 44.8 °F
Dew Point: 59 °F 17 °F 36.6 °F
Humidity: 99% 23% 76%

Anyways, running the second unit is costing us a lot more, but we are
really enjoying using the Den this winter, without the shivering.

I set the both systems for 20C at night and run them at 21 to 22 during the day.
When it's not real cold and damp, 21C is pretty nice.
The humidifier is all set to go, but so far the humidity hasn't been bad.
It's about 35% to 45% RH inside most of the time.
I guess the IDU coils don't get hot enough to really cook the moisture out of the air..

When it gets down into the 20s for a couple of days, we'll see how well
the dual Sanyos can handle heating the whole house.
We are hoping to skate by and not have to burn any oil, (for heating)
or use the ceramic space heater this winter.

MN Renovator · 11-26-11, 03:28 AM

Quote:

Originally Posted by Xringer

I guess the IDU coils don't get hot enough to really cook the moisture out of the air..

There is no such thing as 'cooking' moisture out of the air. That's a myth. Humidity is lost through infiltration and ventilation when the outdoor dew point is low and gained through infiltration/ventilation when humidity is high or through means such as showers and cooking. When running a boiler or furnace that pulls indoor air from the house, the ventilation that is usually through infiltration is what will drop the humidity. Using your mini-splits, the humidity loss will be less than with the boiler, but not because the boiler 'burns off moisture' Humidity loss will increase as it gets colder out and the dew point drops.

Xringer · 11-26-11, 08:56 AM

Well, something is happening to dry up the air up here.. (20% drier).

Here's this mornings numbers:

Outdoors: 54.1°F Humidity: 53 %
Basement: 58°F Humidity: 54 %
Upstairs: 70°F Humidity: 34 %

The dewpoint temp has been averaging about 37F for the last 24 hours. Last 24 Hours Weather: ,

The boiler came on about 6:30 AM, when it was 41F and 80% RH,
but it was only sucking in outside air for about 20 minutes.

Don't know why the RH isn't a lot higher in the house,
since the burner comes on, at a time when it's really damp outdoors.
But, if that cold wet air drops right to the basement floor, it might
be the majority of the air that get sucked into the burn chamber!

If moisture is infiltrating into the house at a good rate, it should be higher.
Looking at the outdoor RH for the last week, Last 7 Days Weather: ,
shows it's about averaging around 72% RH outdoors..
And in here, I'm almost ready to turn on the humidifier..

MN Renovator · 11-26-11, 09:41 AM

41f and 80% RH is a dew point of 35f. If you take air that has a few point of 35f and heat it to 72f, that same air will now have a relative humidity of 27%.

If your dew point is 41f and your indoor temperature is 72, your RH is 33 and if that same air is occupying a space at 55f, the RH is 55. So the air in your basement seems to be the same air as upstairs, just colder because you aren't actively heating it and the concrete/ground is largely controlling the temp.

You are losing humidity up the flue and replacing it with infiltration forced by negative house pressure pulling in lower humidity air.

Xringer · 11-26-11, 11:38 AM

Just went for a walk.. It was 61.8°F Humidity: 42 % and it was great out there!!

So, being warmer, the air upstairs is slightly expanded and will hold less water vapor micro-droplets.?.
Guess I need to do some Googling..

Anyways the bottom line is, I'll have to turn on that dang humidifier pretty soon..

I hate using that thing.. I got a quiet one, but it still makes twice as much noise as one Sanyo ASHP..

MN Renovator · 11-26-11, 11:43 AM

Relative humidity is the percentage of total water that air can hold in relation to when it becomes condensation. 100% relative humidity doesn't mean there is more water in the air, it just means that at that specific temperature the air cannot hold the water and it will either condense on something or simply 'condense out of the air' as steam or fog. Relative humidity isn't an amount so much but rather a ratio. The dew point gives a better idea of the amount of surrounding moisture as its a constant that doesn't vary with dry bulb temperature.

Dew point - Wikipedia, the free encyclopedia

S-F · 11-26-11, 06:09 PM

Dry indoor air in the winter is a sure fire sign of air leakage. That basically is the only reason for it. A tight house 100% never has issues with the air being too dry. The moisture issues they have are all related to too much.

Have you gotten an energy audit Xringer? A blower door test with an IR camera might be really insightful.

Xringer · 11-26-11, 08:10 PM

I did my own energy audit. When the morning sun is on the front door,
I can see the sun light coming in around the edges of the door!

This is a 1956 house and since I've been here (1973), I've drilled a lot of holes in it.
It's a leaky house alright.

A new front and rear door would be nice. And a tighter pull-down attic stairs would
maybe take us down from $2.32 a day to under two bucks..

One area that I can't really do anything about is when my wife wakes up at night,
and opens the bedroom window for some fresh air..

(What she really means is COLD air)!!
In the afternoon when the sun has warmed the living room up a little, (maye 75-78F)
I'll walk into the den and find my wife has the sliding door open a few inches..
Fresh air again?? I just give up and go get a sweater..

If we can keep the average per-day cost of heating, less than the price of one gallon of heating oil,
I'll be happy..

S-F · 11-26-11, 08:22 PM

The pull down attic stairs are impossible to insulate but you can easily air seal that hatch! For the record (and this is from memory) an attic in a 1,000 Sq. Ft. Ranch insulated to R 38 is brought down to R 11 with only a 2'x2' uninsulated attic hatch. That's uninsulated and air sealed! With no air sealing its probably less than 0. Literally.

The wife/fresh air problem can be solved with an HRV

The whole house will have fresh air!

AC_Hacker · 11-27-11, 12:34 AM

Quote:

Originally Posted by Xringer

...I'll walk into the den and find my wife has the sliding door open a few inches...

It's her way of telling you that she wants you to buy and install a high-efficiency HRV.

-AC_Hacker

11-23-11, 07:04 PM	#1
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Heating for $2.32 a day ($66.70 per mo) Using two Sanyo ASHP systems running simultaneously. Sanyo in Stereo? Max heating cap @ 36,000 BTUh x2 is 6 tons. http://i46.photobucket.com/albums/f1.../NCL/meter.jpg http://i46.photobucket.com/albums/f1...0slot/R072.jpg 1240 sq ft. http://i46.photobucket.com/albums/f1.../9784_9784.jpg 310 kWh used during the last 30 days. (They read the meter today). $2.23 a day @ 21.6 cents a kWh x 10.333 kWh per day. That's like a 430 watt load left turned on 24-7. (Our Plasma TV!) This year, heating cost is going to almost double my bill !! Here's the weather info: Climatological Data ------High:------Low:------ Average: Temperature: 69 °F 24 °F 44.8 °F Dew Point: 59 °F 17 °F 36.6 °F Humidity: 99% 23% 76% Anyways, running the second unit is costing us a lot more, but we are really enjoying using the Den this winter, without the shivering. I set the both systems for 20C at night and run them at 21 to 22 during the day. When it's not real cold and damp, 21C is pretty nice. The humidifier is all set to go, but so far the humidity hasn't been bad. It's about 35% to 45% RH inside most of the time. I guess the IDU coils don't get hot enough to really cook the moisture out of the air.. When it gets down into the 20s for a couple of days, we'll see how well the dual Sanyos can handle heating the whole house. We are hoping to skate by and not have to burn any oil, (for heating) or use the ceramic space heater this winter. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less.. Last edited by Xringer; 11-24-11 at 07:12 PM..

11-26-11, 08:56 AM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Well, something is happening to dry up the air up here.. (20% drier). Here's this mornings numbers: Outdoors: 54.1°F Humidity: 53 % Basement: 58°F Humidity: 54 % Upstairs: 70°F Humidity: 34 % The dewpoint temp has been averaging about 37F for the last 24 hours. Last 24 Hours Weather: , The boiler came on about 6:30 AM, when it was 41F and 80% RH, but it was only sucking in outside air for about 20 minutes. Don't know why the RH isn't a lot higher in the house, since the burner comes on, at a time when it's really damp outdoors. But, if that cold wet air drops right to the basement floor, it might be the majority of the air that get sucked into the burn chamber! If moisture is infiltrating into the house at a good rate, it should be higher. Looking at the outdoor RH for the last week, Last 7 Days Weather: , shows it's about averaging around 72% RH outdoors.. And in here, I'm almost ready to turn on the humidifier.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

11-26-11, 11:38 AM	#5
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Just went for a walk.. It was 61.8°F Humidity: 42 % and it was great out there!! So, being warmer, the air upstairs is slightly expanded and will hold less water vapor micro-droplets.?. Guess I need to do some Googling.. Anyways the bottom line is, I'll have to turn on that dang humidifier pretty soon.. I hate using that thing.. I got a quiet one, but it still makes twice as much noise as one Sanyo ASHP.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

11-26-11, 08:10 PM	#8
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I did my own energy audit. When the morning sun is on the front door, I can see the sun light coming in around the edges of the door! This is a 1956 house and since I've been here (1973), I've drilled a lot of holes in it. It's a leaky house alright. A new front and rear door would be nice. And a tighter pull-down attic stairs would maybe take us down from $2.32 a day to under two bucks.. One area that I can't really do anything about is when my wife wakes up at night, and opens the bedroom window for some fresh air.. (What she really means is COLD air)!! In the afternoon when the sun has warmed the living room up a little, (maye 75-78F) I'll walk into the den and find my wife has the sliding door open a few inches.. Fresh air again?? I just give up and go get a sweater.. If we can keep the average per-day cost of heating, less than the price of one gallon of heating oil, I'll be happy.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

11-26-11, 09:41 AM	#4
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	41f and 80% RH is a dew point of 35f. If you take air that has a few point of 35f and heat it to 72f, that same air will now have a relative humidity of 27%. If your dew point is 41f and your indoor temperature is 72, your RH is 33 and if that same air is occupying a space at 55f, the RH is 55. So the air in your basement seems to be the same air as upstairs, just colder because you aren't actively heating it and the concrete/ground is largely controlling the temp. You are losing humidity up the flue and replacing it with infiltration forced by negative house pressure pulling in lower humidity air.

11-26-11, 11:43 AM	#6
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	Relative humidity is the percentage of total water that air can hold in relation to when it becomes condensation. 100% relative humidity doesn't mean there is more water in the air, it just means that at that specific temperature the air cannot hold the water and it will either condense on something or simply 'condense out of the air' as steam or fog. Relative humidity isn't an amount so much but rather a ratio. The dew point gives a better idea of the amount of surrounding moisture as its a constant that doesn't vary with dry bulb temperature. Dew point - Wikipedia, the free encyclopedia

11-26-11, 06:09 PM	#7
S-F You Ain't Me Join Date: Nov 2009 Location: Northampton MA Posts: 662 Thanks: 6 Thanked 71 Times in 58 Posts	Dry indoor air in the winter is a sure fire sign of air leakage. That basically is the only reason for it. A tight house 100% never has issues with the air being too dry. The moisture issues they have are all related to too much. Have you gotten an energy audit Xringer? A blower door test with an IR camera might be really insightful.

11-26-11, 08:22 PM	#9
S-F You Ain't Me Join Date: Nov 2009 Location: Northampton MA Posts: 662 Thanks: 6 Thanked 71 Times in 58 Posts	The pull down attic stairs are impossible to insulate but you can easily air seal that hatch! For the record (and this is from memory) an attic in a 1,000 Sq. Ft. Ranch insulated to R 38 is brought down to R 11 with only a 2'x2' uninsulated attic hatch. That's uninsulated and air sealed! With no air sealing its probably less than 0. Literally. The wife/fresh air problem can be solved with an HRV The whole house will have fresh air!