Taffy:

Flowrate primarily depends upon pump size, pipe diameter, constrictions, amount of antifreeze in pipe, and pipe length. You have a 7 degree temperature drop on 2nd stage so it looks like you have plenty of flow. Flow is measured by inserting a flowmeter or you can estimate flow rate if you know pipe length, diameter, pump size, amount of antifreeze, and similar.

If you have a chance, could you get EWT and LWT data a minute or two after the unit comes on and then again at the end of the run (the longer the run the better)? I am in Florida so am not familiar with your area but I find my self wondering if you are extracting heat faster than the loop can provide it or if maybe part of the loop is not functioning properly (note, I just woke up so may not be thinking the clearest and may have missed something in an earlier post).

Taffy, don't worry about rate of flow or reynolds number. Alex's beginning and end of cycle temps could be interesting to us. Though usually, if this is extremely off prescribed amount, the unit would lock out on low pressure.
I don't want you to bombard the serviceman with questions that don't matter a ton. If when he leaves, the air temp delta is in the 20's and he has a satisfactory answer as to why, we don't need to quiz him on geo knowledge. No one wants to believe they're being second guessed by cyber meddlers :)
J

In case there are any Tranq 27 owners out there and just out of curiosity - how often and for how long does your Stage 3 (electric coil) heating come on at:

5'C (40'F)?

minus 5'C (23'F)?

minus 15'C (5'F) ?


Just curious, Taffy

My house is a bit special... my 3rd stage has - never - come on. I know this because the breakers are off.
Ed

Taffy,

My Tranquility 27 3 ton is oversized. 10 KW 3rd stage is available if needed, but has not turned on since it was installed in Oct 2008. 2nd stage just turned on last night at around -3˚F outside. I live in SE/Mid Michigan. My set point is 73˚. My house is 1800 sqft. I'm happy with what I got. Last year in Jan I used about 1000 KWH @ $0.11 per KWH for heat. My EWT = 38˚, LWT = 30˚, 1st stage air side ∆T = 19˚.

Regards,

Masoud

Taffy,
I want to caution you that everyone's experience and design are unique in geo, and what temps auxiliary comes on at for others has no indication of your systems performance.
That Masaoud's system has never employed the auxiliary is proof that his system is oversized as our lows in his area were 10*F colder than design temp last year. While we can argue the + and - of this it still has no bearing in your world.
j

Thanks for the info Masoud and Ed.

I'm in a 1500 sq ft house with an insulated attic, brick construction, 30 year old storm windows, 1/3 bsmt insulated and a 3 ton system. I just wanted some comparisons to what I'm using (and paying) in electricity in the same weather (or colder, if Ed is Alberta - but he sounds fully insulated/green weatherized, so perhaps not as good a comparison).

I keep going back to Tranq 27 advertising and installer hype that promised only a 30% kick-in of Stage 2 in the really cold weather and a payback on $ investment over 7-10 years - I'll be hugely in the hole by then at the rate I've started, with Stage 3 on a lot of the time since October. Will keep working at solutions..................
Taffy

Anyone else besides me seeing these messages as the "smoking gun" bit of evidence pointing at the problem? Leaving air delta T in all stages are way too low as mentioned earlier in this thread by joe and engineer. Water temps and deltas seem OK, so those BTU's have to be going somewhere - we just don't know where (unless the LAT reading is being taken too far away from the heat pump).

Note though that in the last two messages quoted above, Taffy has given us two different stage "3" air temp readings. One stage "3" reading indicates that the compressor is running in second stage as it should, and the fan is running a touch faster in the "aux/emerg" stage as it should, with the expected result of slightly lower LAT. The other stage "3" LAT reading indicates that the compressor is off, and the fan is running at full tilt.

So, is it likely that the compressor is just not turning on at all sometimes (as indicated in the first message quoted), or is it likely that it is locking out partway through a cycle?

(Yes, I'm clearly just doing amateur internet HVAC sleuthing here. Taffy, as Joe has said, please don't bother your installer with my blathering. I'd very much trust the opinion of the resident experts here like Joe and engineer.)

 

Agree on #2, but don't know about #1. From Taffy's message on 01/09/2010 @ 10:16 PM, air-side Delta T is sometimes zero in stage 3. And according to the original thread-starting message a "booster" was added to the compressor because the compressor was frequently not starting at all (guessing this means soft-start).  Perhaps compressor still somehow occasionally just not starting up at all when Y1 is energized, leading to Y2 & W outputs being energized by the thermostat until? (not sure how or if this would be possible - I'd expect that heat pump would never turn off, and house would get real cold). Again, just pure amateur speculation on my part, especially without better data.

A couple of clarifications:

Yes, to soft start kit install back in December.

The 65-68' air reading was at first floor vents, not as it leaves the unit where other measures were taken - thus the discrepancy.

Heat pump rarely turns off and is rarely even in Stage 1, even though temps have been much milder for the last 3 days.

Changed my setpoint on thermostat to 74' to see if that would get me a bit warmer on second storey - but it never goes above 71'.

That tells us a lot....no lockouts or compressor not turning on to worry about, just not enough heat being put out by the heat pump compared to the manufacturer's specs. As usual, the best advice here has come from the pros.... Joe's message from 01/10/2010 @ 7:31 AM tells you all you need to know.

I missed Taffy's note about the 68* temp at registers. It could be relevant, but not without supporting data- was heat pump running or at end of cycle, what was EAT/LAT, should heat pump have been running but wasn't?
Not a bad catch for a "pure amateur" jml.
If heat pump was running and LAT was 83 but only 68 at registers that would be a a large loss after leaving the heat pump. That could be a smoking gun, but not without more info.
Taffy perhaps you could add temp at the register to E and LAT measurements.
J

I had made a comment earlier about the possibility of cold loop water circulating in Climadry reheat coil. I have realized that Taffy had listed the model info for the heat pump. Climadry IS NOT involved.

I have another non-professional opinion. A bad CXM board can result in intermittent compressor operation, without generating fault signals or lockouts. This can result in a lower than normal heat output. We saw an example of this last summer, a problem Porsche998 had. I heard about a similar problem from another person, in 2008.

I have two questions for Taffy:

1. When you listed 3rd stage LAT (80.1˚), was the breaker for electric coils on or off.

2. Have you tried in cold weather (around 7˚F, your winter design temp), to run only the 10 KW emergency heat (without compressor working), for a test? This test will put a fixed amount of heat, about 32,750 btuh, to your house. You can get an idea about how well the house retains heat. I believe you can select emergency heat from your ATP... thermostat, while breaker to electric coils is turned on.

Regards,

Masoud

Oh, I forgot to mention if you do the test, do it for just an hour or two. Don't bill me for electric cost. It will be helpful to know EAT and LAT with only emergency heat on.

Regards,

Masoud

Masoud,
Taffy has indicated a Delta T when the system is running that is less than spec.
That tells us 2 things:
1) the compressor is running (as she told us the breaker is off for aux and there is still an air temp DT).
2) something is wrong (as DT is only about 13*f).

I've encouraged Taffy to stay focused on this as it is a tangible problem to explain to the repairman.
Among the enemies of trouble shooting is extraneous information. We often see it here where someone's first post is 1, 8 thousand word paragraph. Bombardment of sundries obscures valuable information.
I agree with you that once we get a proper delta T in air temps, your test would help identify heating requirements if trouble still exists.
j

Joe,

Your remarks make good sense. Thank you. Taffy, listen to Joe and stay focused.

Regards,

Masoud

Stage 1 - Temp differential at the register closest to unit on first floor is averaging 0.8 'F different than LAT, at a first floor register 20 feet away a 3.7 'F difference

Stage 2 - Temp differential at the register closest to unit on first floor is averaging 0.6 'F different than LAT, at a first floor register 20 feet away a 3'F difference

Even though weather here is quite mild (30' - 35'F), Stage 2 is on most of the time. Perhaps I need to be happy it's not running at Stage 3......???? :-)