Ontario Electrical Usage for Waterfurnace Premier Seems Way Too High

Ecobee support got it sorted out in a few minutes. one wrong setting on my part (I chose Rh + Rc, and should have only chose Rh). So geo unit is now operating with heat pumps first. Also adjusted threshhold times so 1st stage runs minimum 30 minutes, and Aux does not kick in until at least 60 minutes.

Also then ran 1st stage geo and 2nd stage geo to check temperature differntials (I don't have the equipment nor the cajones to check fluid pressures).

This is what I measured:

1st Stage:
Air In: 70.8F
Air Out: 100.4F
Coolant In: 55-56F
Coolant Out: 51F

2nd Stage:
Air In: 73.0F
Air Out: 103.6F
Coolant In: 57-58F
Coolant Out: 49F

Will see what happens tonight with these adjustment as it will get chilly again. Don't know if any of this will have any positive impact on my excessive elctric bills from the past winter.

Andrew

 

Andrew,
Having a 23 degree plus delta T across the Unit tells me the Unit is operating, with a 3 degree improvement over the last data you provided here.

If a Resistor Bank was operating, I would expect a lot higher delta T out of the Unit than 23 degrees.

It doesn't appear that the Unit has been damaged by water.

 

Glad to hear that it was a simple thermostat adjustment....

 

Heat during the night ran under Stage 1 geothermal only after the adjustment. These are readings I took on the furnace unit yesterday afternoon.

Anything out of normal in these?

 

Looks good. You can slow down the fan a bit more if the noise bothers you.

 

Some things I noticed on your data table: Your compressor does have 2 stages, even though someone said your unit is a single stage. The Aux Heat is the resistive heater bank, and the Unit Compressor shuts off when the resistor bank is energized. Consider doing some research or asking questions here to determine if it would be to energize the Electric Resistive heat with the Geothermal Unit running in order to complement each other, raising the house temperature rather than all Geothermal or Electric heat operation as it currently is set up.

Your variable speed fan is set up for Medium speed in stage 1 and High speed in stage 2, which makes the data appear that deta T/ increase in heating in Stage 2 is small for a large increase in compressor amps. The air flowing faster is resulting in a small increase in delta T. Since this is a heat pump which relies on greater air flows to move the heat into a home, I would change the dip switch setting for high speed in stage 1 and stage 2.
Some may not agree with this, but that's how Carrier sets up their 2 stage geothermal Units today based on one that I have in another house.

Your Geothermal Unit performance appears to be improving with each set of data you provide. Has something changed since the Technician was at you house?

 

Andrew,
I was interpreting the table that you were showing as a read out when you put the unit into test mode and let the aux come on without the compressor.
If in supplement mode heat in the real world, the aux should not come on alone but in addition to the compressor running, make sure you have that setup selected at the thermostat.

 

Usually the units are setup that the blower increases between stage 1 and 2, so the delta T on the air side remains stable. Indeed this is a heat pump, and this is why the air flow increases with a higher compressor stage.
Stage 1 operation makes up 85-90% of the total operation. Why would you run the blower at high speed with the compressor in low speed?
Much lesser comfort (noise, colder supply air, higher draft), significantly higher energy consumption, and lesser equipment life (blower), with only marginal lower compressor efficiency on the plus side. You probably gain 20 watts on the compressor, but it costs you 200-250 watts on the blower.
It beats the purpose of a variable speed blower. You tell people to generally just crank it up because the dip switch setting on your single carrier unit (probably by accident) had it that way ?
Let me ensure you that at least Climatemaster, Waterfurnace and Bosch all ship it with medium setting on the blower in 1 stage.

 

I knew it had 2 stages based on the manual I have at the cottage. I saw that too, but I figured it was only running electric without geo because I had entered the test mode on the Ecobee, and so i would think if you are testing modes, you don't want other modes running otherwise that would make it difficult to identify problems with specific heat modes. Something I did notice that was "interesting", my Stage 2 geothermal delta T (air) is about 29-30F, while the electric resistive delta T is is only 23.5F when the unit is going full bore (65 Amps). I am assuming that the blower speed was the same for both modes (high). Surprised that the heat differential was worse than the geo stage 2. Could be naivety on my part. And does the ramping up of amperage that I recorded in Aux. Heat mode make sense? It looks like it jumped up in 20 A stages. So at beginning 20 A heat + 3.7 A blower (which is ~ 4 A I saw on both 2nd stage geo heat and cool modes for the fan), then another 20 A added to heat going to total of bout 45A, then another 20 A jump up to 65 Amps at the end (and I culd make the case that air temp deltas would jump by 7.5-8 F per 20 Amp heat usage)

I wonder if the heating differential improvement between Tech visit in March and 3 months later in June could be due to the approximately 20F increase in EWT (from 38.5 F in March to 56-57F in June)

Also if you look, the geo heating deltas (in June with warmer incoming coolant temperatures) is is around 28-30F, whereas the cooling deltas is on order of 19-20F. Which is about the same as the heating delta back in MArch when incoming coolant temperatures were colder.

 

I was going to ask about that, but you have answered that question. Now I will want to test that out on the unit by raising the temperature by say 3F to trigger the units natural tendency to go into Aux Heat when large changes are requested. Possible problem for testing this next weekend is forecast temperatures of 28-30C (82-86F)

 

Aux only might have less capacity than the heat pump running at 2nd stage, depending on the size of the aux heat. It usually does come on in 5 KW stages (banks).
At 32F incoming water, capacity is around 54 KBTU, when at 60F it is around 75 KBTU, explaining the higher delta T on the air coil.

 

Andrew,
The loop water getting warmer as the Geothermal runs less in the Spring will improve the performance of the Unit, I wasn't aware of how cold the loop was getting in the winter.
I know someone who would never use a Closed Geothermal Loop while sitting next to a large lake. He always uses an Open Loop when he has an unlimited heat sink like you are siting next to. The lake you described would have a relatively constant water temperature at the bottom of the lake all year.

For an Open Loop you would need a Screen or Strainer on the suction pipe in the lake to keep curious minnows and bottom materials from getting into the pipe, and a Filter in the house to pick up any dirt or small pebbles that might make it through the suction Screen. The suction should be far enough in to the lake to pick up water at a depth unchanged by Winter or Summer temperatures seen by shallower water. I'm sure some will cry out that you need the Cupro Nickel heat exchanger if you are using an open loop system, but the option you are facing now is replacing the Geothermal for a more efficient heat source. Reducing the life of a Unit by exposing it to Open Loop contamination isn't an issue in your case. Besides, no one can predict how your unit will react to direct exposure to lake water without knowing the chemical content of the lake water. Someone could charge you the cost of a new Geothermal Unit conducting an extensive science project then tell you that your unit will be fine. I'll check your Unit Model numbers against your owners manual, you could have been sold a model with Cupro Nickel Loop Heat Exchanger.

The Resistive Heat units that are used as a back up to the Geothermal Unit that I have seen is one bank of heater elements that fits on the outlet of the unit. Even though it would be possible to have 3 banks stacked on top of each other and use contactors to add each bank over a set period of time, I don't think home Resistive heating Units would be that sophisticated. You would hear the contactors picking up when each current step occurred.

If the current reading were taken seconds apart, you might be seeing the heater bank responding to the temperature rise of the elements. Depending on the material a heater element is made of, it could have lower resistance with temperature causing current to rise, which could explain the current rise with time.

You said:
Also if you look, the geo heating deltas (in June with warmer incoming coolant temperatures) is round 28-30F, whereas the cooling deltas is on order of 19-20F. Which is about the same as the heating delta back in March when incoming coolant temperatures were colder.
Use your owners manual Performance Tables to look up expected Air and Water delta Ts for a given loop temperature when in Cooling or Heating mode. I've never compared data between heating and cooling modes since the Owners Manual treats them as different enough to need a separate table for each mode.

Next time the Aux Heat starts up, listen to the Geothermal Unit Compressor to determine if it is running with the Aux Heat. If not, I'm sure there would be a way to wire the Thermostat to signal both heating methods to run at the same time, unless there's a reason why running both heat sources together would create a problem that I'm not aware of, since I've never used a back up Resistive Heat source.

 

Andrew,
Good news, you have a Cupro Nickel water side heat exchanger which is recommended for an Open Loop system.
Your Unit is a P070TL111NBDSSA. The N specifies the Cupro Nickel water side heat exchanger. C would have been copper which is less resistant to corrosion that could occur if loop water temperature was corrosive.

 

Waterfurnace aux heat elements come in stages, for example a 10 KW heat element turns on 5 KW first and after a time delay turns on another 5 KW. The banks are not above each other, but next to each other.

Never ever pump water from the bottom of the lake to a ground source heat pump. It is to dirty, has algae and fish larvae and other biological growth in there. It is not the corrosion which is worrisome, it is what is in the water. There is a reason why closed pond or lake loops were developed. Plus the potential savings of warmer entering water is used up by significantly higher pumping power. Using a filter is a nightmare given the 1+ million GPM going through it. Manufacturers have strict water quality requirements which lake loops never fulfill. The water at the bottom of the lake will be 39F all year around, which is usually close to the average annual temperature of a closed loop, so you don't gain very much for heating purposes, you just gain headaches, maintenance nightmares and significantly higher pumping power.

More importantly, given that you will have 39F entering water temp at the bottom (and colder water further up to avoid sucking in sediment) what do you think your leaving water temp will be in Ontario after you took out some heat. Plus keep in mind that now the temps on the heat exchanger will be below freezing. What do you think will happen to the water not containing antifreeze being exposed to the wall of the heat exchanger which is between 20-25F under those operating conditions? Now yo might understand why open pond or lake systems are not doable in northern climates.

You continue to really bad advise to people, which displays your lack of knowledge on the subject as well as your lack of experience.

 

I was not considering open loop, for the reasons stated plus my situation where the bedrock is shallow so the lines are not buried all that deep, and in one place by the shoreline exposed to air. They can get stretches up here with -30C temperatures for a week in winter and I can only imagine what would happen in a shallow water line at those temperatures, and frankly, even milder temperatures like -10C.

My unit has I believe 60 kW of heating, certainly supported by my amperage measurements at the end of my testing last weekend. That it only increased temperatures by 23F at 65 KW load vs. 29F temperature increase under Stage 2 geo at 36 kW is pretty underwhelming performance to me (for the electric). I am wondering, should I set the thermostat to even let geo try to heat up the place a lot longer before kicking in electric auxiliary heat? (say try for 2 or 3 hours at Satge 1/Stage 2 before adding electrical?) Or do I risk running geo too long at 36 kW load for possibly no increase in heat during cold winter periods (because heat loss matches heat added by furnace) where it would be more economical to get a short boost of added electrical heat in order t meet the set point temperature?

 

It is never economical to bring a space up to temp with aux heat. Let the compressor run as long and as much as you can. The largest heat element made by Waterfurnace is 20 KW, which fits 65 Amps at 240 Volts. Yes, that is the trick of geo, much more efficiency than resistant heat.

Usually the blower speed is even higher with aux heat on, depending on the settings, which might explain the lower discharge temps. You aux heat should have just shy of 70 KBTU/h maybe 5 kbtu/h less than the 1st + 2nd stage.
Set it and forget it, and have the heat come on not on a timer, but when the indoor temps fall below a certain threshold.

 

Andrew,
If you look up information used in AC Electrical theory, you'll find there are Resistive, Capacitive and Inductive devices. Resistive devices like Toasters, Water Heater Elements, Hair dryers and the like, convert 100% of AC power (sine wave) into heat. Motors and devices driven by a motor such as a Compressor or Fan are Inductive devices which due to AC power alternating current at 60 cps will build and collapse a magnetic field at this rate using approximately 60% of the energy entering the device. The 40 percent is returned to the grid and doesn't get billed by your electric meter.

The Geothermal Heat pump compressor using 36 KW of Alternating Current to compress Freon has a dual amplifying effect of producing the heat of a 50 KW Resistive device and the magic of Freon (latent heat of vaporization) being worked on by the compressor also produces heat. You end up with more heat production by your Unit per KW of power used.

Your table does show approximately 20 amp increase intervals over time on your heater bank. That would have to be a step increase of adding heater banks unless we are being fooled by the readings being taken over a very short period of time and the current is actually increasing with the temperature of the Heater bank. I'll look at your manual to see if it included how the Resistive Banks of Aux Heat are installed and operated. My Unit manual doesn't show the Aux Heat but there is a possibility that Water Furnace provided details of their typical design.

I didn't think about the shallow & exposed runs of loop pipe that could be frozen by the winter temperatures while the unit is off, if you didn't use a closed loop with antifreeze.

Without Aux Heat your Geothermal Could run 24/7 as is happening to Maurice on this website, when the Unit Performance is poor and the heat produced is less than heat lost on a very cold day. Be careful not to open the Aux Heat breaker and forget to close it when leaving, as some home owners have done to prevent the electric backup heat from coming on when raising the thermostat after arriving home after work for instance. If possible raise your thermostat setting in 2 degree increments to return the Cottage to at home temperatures without starting up the Aux Heat.

Since the previous owner was able to get by without adding an additional heat source, you could have a performance problem that only shows up when the Cottage is operating at its limits in the winter where a 10% loss of efficiency shows up as heat lost being greater than heat produced without that 10%.

The loop temperatures going down in the winter along with the loss of capacity/efficiency of the Unit is more than likely the cause of the high energy use by the Aux Heat in the winter. I would keep looking for a loss of Efficiency cause in your Unit, plus look into a Propane Aux heat source due to increased electricity costs planned by your electric supplier.

I have 2) 500 gallon propane bottles for Emergency Backup heat on a Heat Pump heating a trailer, and I use gas logs in my home as a backup heat source to my Geothermal in the Winter. You can add a whole house gas furnace supplied by Propane by changing an orifice in the burner gas regulator.

 

His heat extraction is right on target, demonstrating that the unit is putting out the specified BTUs when running. He can look for a loss of efficiency for a long time, but the numbers show that the unit and its efficiency is running at specs.
All we know was that the unit was not putting out any heat when it got a Y1 or Y2 signal, and that aux heat was bringing the temps up (with electric resistance heat).

Andrew, keep us posted. Did you put the unit in heating mode and did the compressor engage?

 

Will be up this weekend and will run a test then.

 

make sure you raise the thermostat, do not use the test mode.