New here. have a couple questions

[rockyrunner99]

Hi all. I am just a homeowner basically. I am a really advanced diy. I have 2 projects coming up and would like some opinions. The one coming up this summer, is I will probably be installing a geothermal system for my parents. We have been thinking open loop. There is the water quality issue though. I have seen a few threads on this. I have tested the water and the good news is no iron. I am planning on having a professional test it. Can a lab give me a scaling index number. or will it still just be hardness and ph? I know there are a lot of differing opinions on this, and it is debatable.

Question 2

My next project will be doing a water to water heat pump in my own house. I currently have a water to air heat pump. I have tubing ran in all my floors for in floor heat and I want to get that going. My current heat pump is a 3 ton and it is perfect. I know with the in floor heat. I will loos more heat. (I have a concrete floor poured on sand and 2in HD R-10 foam with poured walls around it) Heat down into the ground. I also plan to heat my hot water with it. I have several questions about setting this up. First is the sizing. Should I go up to a 3.5 ton? or should I use a 3 ton and the one or two times it gets really cold, let the water to air pump kick on? Will that make the water to air pump short cycle too much? I also have a fireplace I try to have going on the days it gets really cold. Next question is, how big of a storage tank should I have to buffer the demand of the heat pump. I have 6 loops of in floor heat all about 275 ft in length. with a total loss of around 33,000 btu plus the domestic hot water. (that wouldn't be including heat loss from the slab into the ground)

Thanks in advance. I look forward to being a member here, I love learning and talking about this stuff.

[SkyHeating]

This forum does not allow DIY advice for installation, however I can give you some basics.
If you plan on doing a water to water heat pump and doing domestic water you will need secondary heat exchangers in most cases. I would always recomend one to be safe anyway so you don't have any risk of something breaking and contaminating potable water.
The only way to know what size heat pump is to do a load calculation and this will account for the radiant floor system and r10 underfloor then you need to look at the equipment charts and find out what EWT you will have so that you ensure that at the EWT's you expect for your water to water heat pump you have enough BTU's to cover your load.
If you plan on heating hot water with it you might need around 12K BTU's extra. Water Heating typically is only around 2K BTU per hour but when the load occurs it can take 12-20k BTUs in one hour and then not need any for the next 18 hours.

[TACKERDOWN]

Not to be rude but shouldn't a really advanced diy realize you can't just wing your btu need let alone what you need for radiant water to water.

[rockyrunner99]

wow, thanks for the warm welcome. Yup, I plan on a plate style heat exchanger for the domestic hot water.

I have a professional heat load calculation done for my house. My current 3 ton heat pump was sized from that, which is perfectly sized in my opinion. It included the heat loss through the floor, with the R10 foam. How much more heat will be lost through the floor into the ground when the floor is 80* vs 70*, or 60* is more like what the floor is frequently.

[TACKERDOWN]

What radiant loop water temps did your heat load come up with?

[rockyrunner99]

the heat load was done for the forced air heat pump. So back to my original question though. Since I have a sufficient source of heat. Does the size of the heat pump for the radiant heat really matter? I just want to warm the floors. My well is big enough to supply both with water. The only issue I see is short cycling on the forced air heat pump. Again, I also have a fireplace I try to have going when it gets really cold. Why do I need water to water heat pump capable of fully heating the house. I could get a smaller more efficient one, and less expensive. As for the water temps, I have done some calculations on a few programs and came up with 115* should be the highest I should have to have to heat my house.

[TACKERDOWN]

Back to the top. I would get a heat load done for your water to water. Skyheating already said how you need to start this job. This will more than likely answer all your questions. Once you know what you need you can decide where you want to take it from there.