South Carolina Undereducated Newbie with general questions

A couple comments:

1. The specs @gsmith22 posted do indicate lower pumping power than reported, but there are numerous posts on here reporting pump wattage at about 245W for a single 26-99 pump. I'm not sure where the difference comes from.
2. While I would have also said the pumps are not inside the units, one of her units is a 506A11 outside packaged unit. Looks like these are available with flow centers pre-installed inside the cabinet. Options are for none, single, or dual-pump flow centers. Looks like these have one or two 26-99 pumps in them. The Waterfurnace model number should indicate what's installed.
3. For the other (500A11) unit the flow center should be outside the unit, as @gsmith22 described.
4. I'd guess that each unit has a single 26-99 pump, but looking at the part number on the pump in the flow center is the best way to positively identify what's installed.
   
5. Based on the reported pipe diameters and loop sizes, I don't think there should be a problem getting the required water flow unless the supply/return lines are extremely long. If you have the monitoring package, I believe it will report the loop flow in GPM. It's not easily accessible for the user though.

 

My model number is listed on the screeshot above. As far as I can tell from the info from Waterfurnace, I have a variable speed ECM. The flow center is a bottom connection and listed as FC1-GL. I have no idea what that means. This is the outside package unit that is a bit unique apparently. Has a dual stage compressor, 10 kw factory installed heat strips, intellistart, and has the Aurora performance and refrigeration package.
The monitoring program shows pump info as wattage being used, not gpm.

 

According the the Waterfurnace documents from 2017, the FC1-GL uses one single-speed UP26-99 pump, and is rated to consume 246 watts. So, everything looks on track there. This is about as efficient a pumping setup as you can have without going variable speed, so that's good.

Your entering water is at 52 degrees, so you have no apparent issue with the loop being too small.

Nothing I've seen points to an equipment or loop problem, other than the downstairs system being too small for the heat load.

 

yes, the clarification of the UP26-99 pump would indicate much more flow than needed (using the power curve vs flow chart I posed back in reply 16). 4 ton unit needed for downstairs

 

Thanks you guys. I really appreciate all of your input. We will be meeting with our contractor this week to discuss the installation of a 4 ton unit.

 

Good luck. While he's there ask him to use the AID tool (or his installer Symphony web interface) to show you the water flow rate on the system as it stands now. Your unit has the sensors to measure water flow, but you don't have access to it in the owner's interfaces.

 

Thanks. Will do.
Out of curiosity, does anyone know what the real difference in price should be between a 3 ton and a 4 ton unit outdoor package? I realize I need to consider costs of the trenching, additional tubing, and a different manifold for the extra lines that need to be put in. I haven't seen the actual real pricing of the units anywhere and was wondering what you guys feel this should cost to upgrade the system.

Thanks

 

A really good installer would eat the cost difference, since it was their error installing a system that was too small.

Check your contract. Many will guarantee the system will maintain temperature. My contract did.

There was a 2015 price list posted on this forum, but that was before package units were offered. The cost differential between 3 and 4 Ton units is minimal--a couple hundred to a few hundred dollars.

 

I said it in a prior part of this thread and maybe it was missed or glossed over so I'll say it again here: Nothing you have reported indicates you have a loop problem. Loops are sized for heat transfer throughout the four seasons of the year - its a huge averaging mechanism based on climate/location. Your primary issue is the size of the downstairs unit. Units are sized for heat loss or heat gain of your home at temperature extremes - middle of summer on hottest day and middle of winter on coldest day. Which is excatly the problem you experienced - unit couldn't meet thermostat demand during the coldest part of the winter while the loop temp remained in the 50s (common for loop temps to get into low 30s in the north in a heating climate). If the contractor tells you that you need a bigger loop (and everything that involves) because you are now putting in a larger unit, this strongly suggests they have no idea what they are doing from a system design standpoint. I call these folks "parts hangers" who jsut keep replacing stuff until the system works (typically at your expense). I would ask them why they think you need a bigger loop when the loop temperatures were in the 50s which is well above the rated use for your heat pumps. Wouldn't that loop temp mean the loop isn't an issue? (Or something along those lines). Size of loop has nothing to do with size of unit. Contractors like to equate the two using rules of thumb because "math is hard". Before I would fork over any money for a loop increase, I would verify the loop size using LoopLinkRLC (free online google is your friend). You may need to have your house's heat loss/heat gain as an input to LoopLink RLC which can also be done free online with CoolCalc.

 

Just to follow-up, we did have the 3 ton unit replaced with a 4 ton unit last july. We had one more 200' trench installed. Recently we had a 12° day with a wicked windy windchill of -5 which for us in SC, is a 30 year record. The waterfurnace held up just fine. We have to backup heat strips set to not come on until it gets below 18 or so and overall, we are quite pleased with the results. I am satisfied that our dealer did us right with the switch. We paid the difference that would have been between the original price of the 3 ton to 4 ton units and also for the additional trench. Overall, we are pleased.
Now I just have to figure out what to do for a backup generator. Thanks for all the support from you guys.

 

Sounds like a good outcome. Thanks for updating us. How often to the heat strips come on now? Did your heat strips need to come on when it was 12° outside?

 

The heat strips for our downstairs units did come on during that 12 degree period. My symphony app says we used 183 kw of power for the aux heat in the month of Dec when it was so cold. It was quite cold for us for about a week. We used NO auxiliary heat in Nov, Jan and Feb (so far).

 

That's not bad. I need a little AUX heat when it drops down to about 15°, if I want to keep the inside at 70. I used 41 kWh in Dec and 7 kWh in Feb. Some was due to recovering from a setback.

 

I live in Virginia with a 4 ton, five series and a 2 ton, 5 series water furnace units and to my knowledge they have never gone out of stage one! When I built the house I did spend a few thousand dollars on extra foam insulation in the walls and floors so I feel that the house is extremely tight.