Water Furance Envision Problems

Not offering much information, just suggesting a different course might yield more results in troubleshooting.

Manj load calc would have heat loss/gain.

 

update.....

Hello Everyone,

Just wanted to provide an update on my situation in hopes you can help me find a solution.

After the new loop was installed (last week of July,recomended by the factory tech), the performance has not changed. The tech said it would take 4 weeks for the temps to stabilize which was the last week of August. On days greater than 90, the temp continues to rise until it hit 78-80 (thermostat set on 74). Stays in stage 2 from around mid morning to midnight or later. Now we have hit a cooler spell of weather so I can not accuratly compare it unless we hit 90+ again. Only thing I can mention is that the unit went off last weekend during the night, we turned the breaker off and on and it started back, it took all day (7pm) to get to 74 (from 80). Seems sluggish to me.

I asked the contractor if he would be willing to call the other WF dealers who quoted the job and compare notes and figures. The other dealers quoted a larger unit.
he was willing and has done so. His feedback to me was that they did Block load in their calculation, his was more accurate with a Complete load.

He also mentioned that we need to do a blower door test. I do not know the numerical values but he said my house (stick built in 1994) needed to be sealed better.

Seems like a good test but just wondering why this was not done on the front end. Now he came and sealed around the vents. I asked him to quote a larger unit and he said I just needed to make the house tighter. I also went thru his program for entering data to determine unit size, I did not see an entry request for blower door test, only quality of construction.

It was tight enough for my air source heat pump that the geo replaced to keep up in the summer, it was a better performer and my bil was actually cheaper when I compare this year to last (when we set records for days in the 90's.) My bill was $230 last month.

We had a lot of rain this week and the dirt at the new loop is sinking in places, 6-12" I assume it was not packed.

So I am looking to you guys to help steer me in the right direction. The unit did not perform well after it was installed in cold weather (air temperature cooler than my air source). I don't want to wait until next summer for it to hit the 90's again.

Should I get a blower door test done again to see what readings we get?

 

With all the rain you have had

......it might have been good to go water to water..
.
The loop side of this system is either, not plumbed correctly or it is full of air.

Can you post a picture for us late night folks?

 

Okay GC, I took 'em 1 at a time for you, but let's reiterate:
The heat gain calculations will tell us if the equipment size makes sense. Let's get results from more than 1 bidder and share the btu total. You may also want to load the house out yourself.

That said:
I think there is an excellant chance you have a loop blockage. Whether piped wrong or kinked, air locked, or simply not well compacted, I don't think heat is getting properly rejected into soil.

There is an easy test when flusing to determine kink or air lock. Any experienced geo pro would recognize it.
j

 

I will get my wife to scan the documents I have. If they are not what we need to review, I can ask the contractor for more.

Here are some responses to you responses. I appreciate the feedback, my perception of how things should work may be different from what way they will work. you guys have the experience with these units to fall back on.

After the new loop was installed (last week of July,recomended by the factory tech), the performance has not changed.

1) The tech said it would take 4 weeks for the temps to stabilize which was the last week of August.
Did they say stabilize or settle (implying compaction)?
He said the ground temperatures needed to stabilize, the ground was just too hot.



2) On days greater than 90, the temp continues to rise until it hit 78-80 (thermostat set on 74). Stays in stage 2 from around mid morning to midnight or later.
If your design high is 94, I would expect you to spend a lot of time in 2nd stage on days higer than 90F.
That helps me understand what to expect.

3) Only thing I can mention is that the unit went off last weekend during the night, we turned the breaker off and on and it started back, it took all day (7pm) to get to 74 (from 80). Seems sluggish to me.
Sluggish based on what? If temp was rising outside and falling inside, that doesn't necessarily suggest a problem.
It is falling inside but slowly. it took 10-12 hours to go from 80 to 74. Maybe this is normal? The contractor stated the performance (recovery) was sluggish.
4) I asked the contractor if he would be willing to call the other WF dealers who quoted the job and compare notes and figures. The other dealers quoted a larger unit.
he was willing and has done so. His feedback to me was that they did Block load in their calculation, his was more accurate with a Complete load.
Is there any reason you won't share the results of these load calcs? This is one of the major pcs of info we need.
At the mercy of my wife who will scan the docs.

5) He also mentioned that we need to do a blower door test. I do not know the numerical values but he said my house (stick built in 1994) needed to be sealed better.
Load calc should represent loss/gain in homes present condition. While tightening up a house isn't a bad idea, equipment was presumably sized for house as is.
Blower door test was done but I do not know the numerical results. I agree it is a good thing but would expect it on the front end.

6) It was tight enough for my air source heat pump that the geo replaced to keep up in the summer, it was a better performer and my bil was actually cheaper when I compare this year to last (when we set records for days in the 90's.)
What size was your ASHP? You set records last year? This year? Both?
It was a Luxairre, 2 or 2.5 ton, I will have to look at the unit tag or manual. Last summer was the record setter, this year has been hot just not as hot as last summer. If it was equal in temperature, I would expect a cost savings over last year (comparing month to month) August was higher than last year when we were using the air source. Plus I had to buy two ceiling fans to help cool off.

7) We had a lot of rain this week and the dirt at the new loop is sinking in places, 6-12" I assume it was not packed.
How 'bout the dirt on the old loop?
I have not seen any sinking on it I will double check tonight.

Any thoghts on the block load calc vs total? Again, 2 other vendors quoted a larger unit, one used the block load, not sure about the other.

 

What is your EWT after the addition of the new loop?
How was the new loop plumbed into the system (in series with another one or parallel)...and any idea how it could be balanced with the other loops?

My opinion is that the unit should be able to run full time on stage 2 for days and the EWT not exceed 80 deg....but that's just my opinion.

I agree that you must still have a major loop problem whether it be trapped air or a kink in the pipe.
If the trench sunk 6-12" that means it wasn't compacted AT ALL and you might have all kinds of air pockets around the loop pipe which keeps it from conducting any heat into the ground.

Without reading all the previous posts, did anyone put a flow meter on the loop to determine your ACTUAL flow rate?

A larger unit will actually perform even worse since the loop temp would simply go up faster and consume even more electricity.

 

Here is the info I have, if you need more just tell me what to request.

The loops were installed (1200', 4 300' loops) in one trench at approx 4'

The additional loop was shorter and the out end and in end were teed into the others. Not sure if it like a manifold or ?

EWT was still hign after installation, contractor said 1 month before it would stabilize, has not been back to check. How can I check it?

This is by memory, but I thought he told be we should have 8 gallons per minute, we have 11-13.

He purged the lines last month it took 30 some odd gallons.

Keep the info coming!!!!!!!!!

 

geocub:

You are not hearing the questions.

Joe is good and you should give him the info he askes for.

I am a hack who does this so I can type to you.......

Mike is the best combo man in the USA.

Geocub:

Your loop is not all that it should be. You do not respond with what the posters here ask . It may be fixable it may not be fixable.

Mark

 

(4) loops in one 4' deep trench doesn't sound very efficient (or effective).

I think the technician is correct...the ground is TOO HOT. Because they are not attached to enough ground!

I'm not a loop designer but from what I have read you should be at least 6 feet deep and there should be at least 2 feet of soil between loops to get any effective heat transfer and the shallowest pipe should be at least 4 feet deep.

I think this may have been discussed earlier in the thread.

There should be temp and pressure test ports on the piping but you would need the proper equipment to hook into in. I plumbed in permanent ones so I can monitor the conditions whenever I walk past.
I also have thermometers in the ductwork to monitor air temp change but that's just me.

Did they give any loop design parameters to you or did they just guess?

 

I did not get a loop design.

2 loops, both are side by side in the bottom of the trench.

This came up earlier in this post, if there are industry standards, it would be good to have some input from Water Furnace.

 

Okay,
In the future all you would have to say is "heat load wa 33K Cooling 21K". Lots of attachments do not enhance the answer (nor incidently can I get PDF to show complete sheet).
With those numbers in my AO I would recomment a 2 ton (due to low cost of electricity). It would be nice to know what some of the other bidder's load calcs showed.
If the load is correct, then you are only rejecting 21ishkbtu and your loop field is probably adequately sized, however:
Your installer's knowledge is suspect
Average depth is suspect
Extra loop obviously not compacted well nor likely sized/attached to industry standards

When everything points to poor installer knowledge, it is time to get another opinion.
Perhaps WF wishes to recommend another installer or you may want to check IGSHPA list for qualified loop installers in your area. If you find someone who only installs loops they would be a good fit as they are not technically a competetive dealer.
You might also ask local mechanical inspector who installs a lot of loops.
To sum up,
I don't think the equipment is your problem, I think your installer is out of his experience and I think you have a loop problem.
IOW we are back to where we started pages ago.

BTW are you saying when lines were flushed last month it took 30 gallons total or 30 extra gallons? Was that after new loop added?

Good Luck.

 

Joe

Thanks for the reply and advice. Please move to North Carolina.

The 30 gallons was after the additional loop was added. It may have been 38 gallons.

Does the 11-13 gpm flow raise any flags. I would think a slower pump thru the loop would help disperse the heat better or gather heat better in the winter.

Water Furnace, any thoughts on this?

Kerry

 

Higher flows (yours requires about 6 GPM) can affect loop temp on long cycles. There is a phenom with tight designed loops that will climb (or fall) a couple degrees every 5 minutes (or so) during long cycles. What doesn't add up in your case is the loops don't seem undersized, nor does the heat pump based on calcs offered, so the problem would seem to be water flow.
Are you truely getting that many GPMs or is that the pressure drop.

30-38 gals seems like a lot for one short loop.
j

 

You're in NC - average loop depth of 4' may be fine. Our average depth is 4' and we are in VA. Our loops are at 5' and 3' for an average of 4'.

 

total linear feet on the loop is 1200+260=1460'

I can only go by what the contractor said, he said flow was 8-11 per minute

Can I put a gage in line?

 

That's 1460' of trench right?
Is there just 1 pipe (down and back)?

There may be pressure test ports where the hose kit meets your heat pump, but you need a pro more than we need to continue the discussion here.
j

 

Three pipes. two 600' loops (300' long trench) laying side by side in the bottom of a trench, one that was added later that was approx 500' (250-260' trench).

Thanks for the advice.

As of now the loop construction and packing of the dirt around the loops and the flow thru the loops are suspect.

 

SO they dug ONE trench, 300' long and dropped in (2) 600' lengths of tube in the bottom.
That would mean there are (4) tubes in the bottom of this ~4-5' deep trench that might be 20" apart?
Then they added a ditch-witch trench (less than 6" wide) 250' long with two tubes (one loop) in the bottom of that maybe 4' deep.

I'm just trying to clarify the description.

I hate to say that is you are having so much trouble cooling, your heating will be even worse.

 

Sorry for the confusion, there is one trench 300' that both loops lay in. close together.

The ditch witch loop goes out 250 some feet then makes a loop back. So they actually dug 500' with the ditch witch. I was on vacation that week, he said he averaged 4' there was some rock and the depth varied.

He was not concerned about the depth, he said 4' was as good as 8'.

 

He obviously does not understand the basics of loop design.