Geothermal Maintenance 101 - Heat of extraction / rejection

The first thing a geothermal maintenance technician should is how to complete heat of extraction / rejection. This test will allow you to properly confirm that a geothermal system is performing properly. With this simple process you can confirm that the system is running at peak performance during a maintenance while also preserving the systems life by not introducing contaminants to the refrigeration system.
Special thanks to Water Furnace International AND THEIR STAFF for help with knowledge and training materials (non sponsored).
Water Furnace 7 Series Installation Manual can be found at this link (see page 50 for pressure drop table to calculate GPM)
www.waterfurna...
Water Furnace 7 Series Specification Catalog can be found at this link (see page 37 for the table I used to confirm performance)
www.waterfurna...
Testo 549i pressure gauge (paid link)
www.amazon.com...
As an Amazon Associate I earn from qualifying purchases.

[@LogansRun314]

Brilliant! Should be required viewing for any geothermal tech. Hell, any geothermal owner.

[@hunterfrench2580]

Man, Thank you so much for taking the time to make these videos. My father and I installed geothermal at their home up in VA but I mostly just dug the loop system. He passed away unexpectedly last year and I’ve been super intimidated about tending to it. That guy did everything. We’re from Charleston SC! Thanks again

[@pridemechanical815]

Good to watch content from someone who it's obviously passionate about HVAC.

[@RangeRov49]

Been looking for a channel like this! I myself own a 7 series, so this is perfect content to help me understand my system much better, thank you!

[@tfrancisco72]

Thank You, great video! You don’t get enough credit!

[@buckeyefarmer6259]

thanks, Have 2 geo systems in my house, one is starting to not perform as well as it used to. I use non pressurized pumps, and have a water flow meter to measure actual flow.

[@cooperkimblehvac]

Great video. Definitely want to see more Geo content.

[@Davidandgoliathhvac]

Keep the great content coming Andrew! We really appreciate it

[@iyaayas2246]

Great info

[@jamesshepherd4456]

Homeowner here. Question/comment... Don't they have a sensor that could be permanently mounted on both ports for temp/psi that could report to an app which would do the calc for extraction/rejection number? As a potential owner I would to see that value and know that all is within spec...heck a good app would send me a threshold breach that would let me know of loss of efficiency.

[@aglmechanicaltips]

Water Furnace does when you order their equipment with advanced controls. They use a flow meter instead of pressure though and temperature sensors. It is fairly accurate but when we need precision we do it manually. Keep in mind that homeowners cannot view this information in their app and it is only reported to the HVAC dealers web portal.

[@ramchillarege1658]

Excellent! Thankyou

[@Happyplaceheatingandair]

Great

[@SoGQue]

Thank you

[@elmercifuentes4936]

Do you have any videos on how to troubleshoot water to air geothermal heat pumps

[@Plague_GG]

Do they make inline temperature probes and/or pressure gauges? Would that be better since it would be on there 24/7 and we wouldn’t have to worry about damaging the o-ring or losing refrigerant?

[@aglmechanicaltips]

Yes, a lot of the more advanced systems have built in sensors and you read these from a digital tool. We rarely have to actually probe the units anymore but still train for this in the event a sensor fails or you have to work on a unit that is not advanced.

[@christiansnyder1746]

I have Fieldpiece digital probes. Will that work? Or is there something specific to Testo? And also what brand insertion temperature probe is that?

[@gothducks]

Thank you very much! You answered a question for which I couldn't get a clear answer, temperature IN was 77 so if you are a 68 degree guy, this type of system is not for you. A traditional air to air would be more appropriate for that type of person.

[@aglmechanicaltips]

Negative, water temperature in has nothing to do with the temperature that the system can deliver to the house. There are plenty of houses with geothermal that can achieve 68°. On a "Air to air" system the "tempurature in" on a 95 degree day is 95° for example (when measuring at the condenser coil which is comparable to the water in on a geo). Let me know if I am misinterpreting what you are saying.

[@sameschman1272]

Just curious, why not just have temp guages made into your pts? Coming from more of a boiler background just seems kinda like why? I can see those seals leaking over time. Even with using water based lubricants. Just curious

[@aglmechanicaltips]

You could probably us a temp / pressure gauge but accuracy is very important so large displays are important (1-2 PSI significantly affects the GPM calc). I've never seen that done so I don't know but in theory it is definitely possible.

[@jonkeck5583]

Thank you very much for the info. I am learning geothermal and have 34 years hvac experience. I would be so thankful if you could tell me what fittings I would use to get from the testo 549 to the test tool for pressure. I’m a big fan of testo.

[@aglmechanicaltips]

You will need the needle probe I linked below and a brass fitting. I believe the brass fitting is 1/4" SAE x 1/4" MPT brass (1/4" male refrigerant hose fitting x 1/4 male pipe thread). A HVAC supplier will probably have the brass fitting. Also need some pipe thread tape... geohydrosupply.com/pressure-gauge-probe-1-16-geo-flo/

[@jonkeck5583]

@@aglmechanicaltips thank you very much for that information. Can’t wait to better serve my customer and their geothermal system using the formulas.

[@sean58271]

Why not also calculate the coefficient of performance (COP) when you are doing these calculations?

[@Anton-Hadar]

Where do I connect a roomcooling unit to a geothermal heatpump? When dealing with an airpump the the hot air is heating up the fluid in the airunit that later is compressed by a compressor in the outside unit before it is evaporated out via the fan. So I guess the process must be reversed in the geothermal heatpump as well and the heated fluid leaving the room must be compressed inside the geothermal heatpump before it leaves the pump via the plastic pipes down to the ground.

[@ZenRanger94]

Oh I'm totally putting a bottle if astroglide in my bosses geo kit!

[@ZenRanger94]

By the way thank you for making this and I'm so glad I found it. I've been working on these things for a little over 3 years, and have a pretty good handle on how they work and how to service/diagnose them. However, I've never had this properly explained to me yet. Thank you! More water furnace vids please!

[@JesseDoesHVAC]

Flavoured too for her pleasure

[@RangeRov49]

@@ZenRanger94 Don't ferget yer butt lube!🤣

[@danmccoy6164]

So you would need those calcutaions. If you're doing a repair. Or when setting up the unit. But not for maintenance. Is there really anything that you need to do for maintenance. Other than check the water for ph balance and antifreeze values. And filter on a water to air. Which should be changed out regularly. By the home owner. Basically no maintenance ?

[@Jon-k3p]

When it comes time to replace the inside unit, what is the average cost? Thank you!

[@jessepalacios2321]

Your videos are great On the he/hr= gpm x 500 x td ITS WRONG YOU FORGOT THE HEAT OF COMPRESSION

[@aglmechanicaltips]

Hello, see link below to the installation manual to a water furnace system. On page 73 there is a cooling cycle analysis sheet which we use on the field. The calculation is on that sheet and coincides with the info in the video. Thanks www.waterfurnace.com/literature/5series/IM2500AN.pdf

[@alorentz907]

Hello! To ready the unit can I put it in heat mode vs cool with the fan on high?

[@aglmechanicaltips]

Yes, that would calculate "heat of extraction".

[@tillisross2246]

Assuming all would be the same for a non-pressurized system as long as you know the gpm?

[@aglmechanicaltips]

Correct but you can also calculate the GPM the same way as long as there are P/T ports at the unit

[@merlecorle1890]

Was the second needle part of the Testo 549i or an add on?

[@aglmechanicaltips]

It was an add on. I linked the needle used below. You will have to adapt this using a brass fitting you can find at a hardware store. geohydrosupply.com/pressure-gauge-probe-1-16/

[@merlecorle1890]

@@aglmechanicaltips thank you!

[@Guage22]

My 1st house brought it with it

[@stevemcfarland4661]

Service every 6 months?!?

[@carlyleworkman1928]

👍🏿

[@rgluna70]

I service this unit and NEVER pull out my service gauges

[@aglmechanicaltips]

Agreed, that was the point of the video. Unless there is a known refrigerant issue you should not be hooking up gauges.