Inefficient home or inefficient GSHP?

[skyking]

98904 central Washington of much solar. he *just* had a 9900 watt solar system installed last week
Heat load analysis? The heating company may have but I don't know the results.
3x600 by 3/4 onto a 1 1/4 header.

[AC_Hacker]

Originally Posted by skyking

98904 central Washington of much solar. he *just* had a 9900 watt solar system installed last week
Heat load analysis? The heating company may have but I don't know the results.
3x600 by 3/4 onto a 1 1/4 header.

Sounds like your brothers system is just barely pulling the grade.

It would be a good idea to do a heat load analysis (AKA: heat loss analysis), so that you have some idea where the heat is going.

GSHP and solar heating are considered 'renewable heating' which is another way of saying 'low temperature heating'.

You can't treat it like fossil fuel heat. My bet is that you need to reduce the heat losses.

Infiltration is where it starts, as most heat loss is due to infiltration. A blower door test will tell you how bad it is.

Next go after insulation. Some older houses don't have any... mine didn't have a single bit of insulation, when I bought it.

Put off getting really tight windows till the rest of the house is as good as you can get it.

Reducing the heat loss is a good investment. Your heat pump will reward you handsomely for it.

I followed the construction of your loop field, it all looked good to me... especially the drain lines on top of the pipes. Great idea.

I did a Heating Degree Day (AKA: "HDD") look-up of your Zip Code, and the yearly average is 6727. The higher the number, the more HDD days you have, the more challenging your winters tend to be. I would guess from the number that your winters can be pretty challenging.

Here's a chart from your local HDD numbers, on a day-by-day basis. Looks like you had a killer cold stretch from Oct 18 to Oct 28. I'd say it must have been fairly nippy.

I don't envy you in that cold. Really pays to button up your house as tight as possible.

Also, it is normal with any heat pump system to have an axillary heating setup for those abnormally cold, awful days. You might have a propane heater, or a pellet stove to get you through the tight spots. A heat pump system built to accommodate the abnormally cold days, will be too big the rest of the year. It's a different way of thinking than having your primary heat being oil or gas, etc.

-AC

[skyking]

AC, I appreciate your input and will show it to my brother. maybe we should continue over on the thread I started so as not to hijack this one.
OP, think about ways to heat up your ground economically in the summer hot season. Maybe a grid of black plastic pipe and a heat exchanger to your ground loop.

[mechanic]

What site do you guys use to find your hdd? I tried a few different ones and I've gotten anywhere from 3500-5500. Closest city to me would be Saskatoon, Saskatchewan...

[mechanic]

Originally Posted by skyking

OP, think about ways to heat up your ground economically in the summer hot season. Maybe a grid of black plastic pipe and a heat exchanger to your ground loop.

I'm thinking of doing a solar thermal system with a large insulated water tank in the basement with a heat exchanger for the incoming loop line that I can bypass in the summer and use the heat for a hot water preheat loop instead. Don't think I could use it for both in the winter as the ground loop is quite cold and our domestic water is stored in the basement at room temp, but during winter the cold water temp in the tank would help collector efficiency...

[mechanic]

I guess I could just install some valves and make the lines reversible to put the exchanger on the return side of the loop to pump heat into the ground but I would think the heat might be better off helping the 6000 watt water heater? The extra loop heat would also make it work harder for cooling... My loop is in a clear grass field 8-9' deep that gets full sunlight all summer so I think the recovery is all right - it sounds like the loop is just too small... I know the installer told me the horizontal loops have been outperforming the vertical ones they've put in, at least around here on the prairie anyways...

My heat pump preheats our hot water in heating mode but not in cooling mode, which is weird because I thought the whole point of the water preheat option on the pump was to use the "free" rejected heat to help the water heater out but maybe I misunderstood?

[AC_Hacker]

Originally Posted by mechanic

What site do you guys use to find your hdd? I tried a few different ones and I've gotten anywhere from 3500-5500. Closest city to me would be Saskatoon, Saskatchewan...

mechanic,

It's no secret.

The site is called DEGREEDAYS.NET

I wish more people on this site would use it , to help them to understand other people's heating/cooling situations, and also their own.

Extremely useful, detailed information, at no cost.

-AC

[AC_Hacker]

Originally Posted by skyking

...OP, think about ways to heat up your ground economically in the summer hot season. Maybe a grid of black plastic pipe and a heat exchanger to your ground loop...

You don't need to build an additional pipe system, just run the heated water through the pipe you already have.

-AC

[AC_Hacker]

Originally Posted by mechanic

... it sounds like the loop is just too small...

Your system is basically two parts:

• heat source (heatpump & loop field)
• heat load (water heater & house)

If you don't know what your heat load is, you are just flailing away in the dark.

The heat source in already in place, so find some way to work with it. Get really serious about reducing heat loss... make you heat load smaller.

Please tell me that your water heater is not in the unheated garage.

-AC

[Mikesolar]

Originally Posted by AC_Hacker

Your system is basically two parts:

• heat source (heatpump & loop field)
• heat load (water heater & house)

If you don't know what your heat load is, you are just flailing away in the dark.

The heat source in already in place, so find some way to work with it. Get really serious about reducing heat loss... make you heat load smaller.

Please tell me that your water heater is not in the unheated garage.

-AC

haha, no one in Canada puts a water heater in an unheated garage. I'll bet it will be in the basement.