ASHP question

[hotwire]

If it was 21 degrees outside, then the Fujitsu would be rated at a little more than 14,600 BTUh. If it was the only heat source on at the time I could see how the inside temperature would drop, as it wouldn't be able to keep up with the heat loss of the structure.

My TED5000 doesn't work well with my Insteon light switches, had to put the MTU on two X10 noise filters at the panel in order to get it to work reliably.

Hope this helps,
Kenny

[Xringer]

The guys who gave you those quotes, maybe have been calculating the cooling..
I know my Sanyos do super on cooling. But, there is normally only 5 to 20 degrees F
difference between indoor and outdoor temps during the summer.
When It's 80 out, we normally want it to be 75 (and dry) indoors.

But, the temperature difference during the colder parts of the winter are BIG.
And, it seems like (in my house), it's a lot easier to cool than to heat.

Our Den also has a lot of windows. Even when they are all sealed up,
they are still a big source of heat loss. If the insulation isn't too good.?.
Then maybe it's like Hotwire says, 14,600 BTUh just can't keep up with the losses..

Just before lunch, my wife was cooking, so I closed off the den.
To isolate the 'cooking' air from the den Sanyo.

I turned off the LR Sanyo to keep it's filter nice and clean.
(It's still off because of solar gain).

I know it was 24.2 °F outdoors, but I was still amazed how much heating
the sealed off den still needed.. Sanyo#2 was using 800w most of the time.
After the sun came around from the west a bit, it's down to 600w.
The main reason for this loss (in a 288 sq ft room) is the windows & sliding door.
More than 100 sq ft of window in that room is just too much.
This isn't Florida!!

[poleikleng]

Xringer,

We were very pleased with the cooling this summer but our main concern was the heating. With our oil furnace we keep the house at 62 degrees and this was too cold for the wife. If the worst condition with the heat pumps in cold weather is 62 degrees then we will be happy. I do think we have heat loss and will have to work on limiting that as much as possible. Did you notice any difference regarding heat loss when they installed your siding with the .5 inch insulated foam backing? How do you seal your windows?

By the way, thanks for the picture of the shed you constructed for your heat pump. I built a clone.

Poleikleng

[Xringer]

There are a lot of posts on here for fixing up leaky windows. Here's mine.
http://ecorenovator.org/forum/conser...html#post16189
I also did a solar screen project to allow for better cooling of the Den during summer.
http://ecorenovator.org/forum/renova...n-project.html
That one greatly exceeded expectations!

I don't know if that foam under the siding helped a lot, since it was done so long ago.
IR readings off the walls don't show anything really awful..

Since you have a 1979 house, it might have pretty good insulation.
Check out the attic and see how thick it is up there. You might be able
to add some up there..

In the early 70s, we had an oil scare and people became more aware of Insulation and it's many uses..

One word you used, was "downstairs".. Do you have an open stairwell?
Because, I've seen a LOT of houses that had big heat losses,
since all the heat was escaping upstairs.. (Making it too hot up there in some cases).

They do okay in the summer, since cool air stays downstairs then..
But don't try sleeping on the second floor during the summer!

[poleikleng]

Xringer,

Thanks for the links. We only have a crawl space upstairs and the enegry audit people have installed more insulation in this area. We do have an open stairwell to the upstairs but the only heat the upstairs get is from what escapes from the downstairs. We do not heat the upstairs and it is always 4-degrees cooler in the winter than downstairs and also warmer in the summer than the downstairs.

Poleikleng

[Xringer]

That sounds good. One tool I've found that helped me find heat leaks into the attic (from the living area) is the IR sensor pistol..


I used it to check walls and ceilings around the house too. Works pretty well.
When we had the refrigerant leaking out, I used the scanner and quickly
found the Sanyo wasn't making good heat, while still using a lot of power..
Turning it off when I did, might have saved the compressor.
The repaired ODU is still making heat today. I hope it lasts for a few years anyways.
http://ecorenovator.org/forum/geothe...r-project.html



So, it's sounding like you might be doing some work on your windows.

[Xringer]

Hey Poleikleng,
Tonight is going to be a good test of our systems..
It's only 6PM and it's already down to 18 deg F..
Last 24 Hours Weather: ,

I hear it's going to be down to 12F before sunup.
Woburn Hourly Weather - AccuWeather Forecast for MA 01801

I'm thinking about breaking my own rule about not turning down the temp overnight.
With 2 systems running high wattage all night, at these temps..?.
That's really going add on the kWhs..

Right now, each unit is using about 550w (1.1kw) and both indoor coils
are at about 100 deg F..

I'll decide before bedtime. If it's going to be colder than 12 F, I'll turn it down to 19C.
If not, I'll just leave it at 20C as usual.

Anyways, you might find this local temperature map interesting.
New England Temperature Map
I've watched it for hours and you can see the cold creeping in, town by town.
This map seems to be very accurate for making short term forecast.
You can see the cold before it gets to your area..

This one is good for the whole area..

[poleikleng]

Xringer,

This morning the outside temperature was 13.8 degrees, the warmest room in the house was 62.4 degrees. We had the remote (not mounted line-of-sight) set to 76 degrees. Heat from the inside air handler was in the 115/120 degree range. Our oil furnace did not come on last night. I'm planning to install another heat pump (1-ton) to supplement the heat from the 1.5-ton unit when we have these cold conditions. Too much heat loss, not an ideal floor plan all contribute to unequal heat distribution.

Poleikleng

[poleikleng]

Originally Posted by Xringer

Hey Poleikleng,
Tonight is going to be a good test of our systems..
It's only 6PM and it's already down to 18 deg F..
Last 24 Hours Weather: ,

I hear it's going to be down to 12F before sunup.
Woburn Hourly Weather - AccuWeather Forecast for MA 01801

I'm thinking about breaking my own rule about not turning down the temp overnight.
With 2 systems running high wattage all night, at these temps..?.
That's really going add on the kWhs..

Right now, each unit is using about 550w (1.1kw) and both indoor coils
are at about 100 deg F..

I'll decide before bedtime. If it's going to be colder than 12 F, I'll turn it down to 19C.
If not, I'll just leave it at 20C as usual.

Anyways, you might find this local temperature map interesting.
New England Temperature Map
I've watched it for hours and you can see the cold creeping in, town by town.
This map seems to be very accurate for making short term forecast.
You can see the cold before it gets to your area..

This one is good for the whole area..

Xringer,

What was the temperatue in your home this morning?

Poleikleng

[Xringer]

It got pretty chilly here last night.. Down to about 11F. Since midnight, the average has been 13.6 °F. Climatological Data
But, now that we are heating the den (with Sanyo#2), staying at 20C all night cost us $3.18 (9 hours : 14.8kWh)
$3.18 wouldn't buy one gallon of oil.
I think the units are both using about 850watts each on average, when it's this cold.
The systems seem to be balanced somehow.
Our big peak of the day was likely this morning at around 7AM @ 3.37 kW
meaning 1.685 kW used by each unit. (Each drawing 7 amps)!
My wife turned them up to 21C at around 7AM, so when I got up it was nice!
I don't think it ever dropped below 20C (68F) all night.

It sure was nice to wake up to a nice 21C house this morning!
Knowing that we didn't burn 4 gallons of oil ($3.89/gal) last night, priceless!



My experience with Sanyo#1 has shown it starts falling behind when
the outdoors gets down under 8-10 deg F.
But, now that we have dual Sanyos, not keeping up with the losses might
not occur until it drops down under 4 or 5 deg F..