Hydronic Air design

doctorman

Need help coming up with the best design for a Hydronic Air Heating system

House single family
1) Basement - Baseboard heating
2) Attic and main floor - Forced Air Heat using the hydronic air heat exchanger

putting a HTP UFTC-140 Boiler in the basement
Zone 1 for the basement 60' x 30' area
Zone 2 goes up to the attic 30 feet and goes through the heat exchanger coil blown by the central AC and back. this would be the backup heat for a 5 Ton Heat pump.

Can a Grandfus Alpha 2 handle all that with 2 zone valves?

located in New York Long island.

Thank you



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CoolCalc Heat loss calculation

Cellar
Sensible BTU: 7,497 Latent BTU: 1,556 Heating BTU: 17,408

Main Floor
Sensible BTU: 10,926 Latent BTU: 2,216 Heating BTU: 23,215

Attic
Sensible BTU: 9,665 Latent BTU: 1,648 Heating BTU: 18,409

Jamie Hall

Add up the head loss (not elevation difference!) through the piping to the heat exchanger coil, then through the coil and back to the pump. Then look at the Grundfos pump curve and find out what flow it will produce with that head loss. If it will produce enough flow to dump the amount of heat you need, you're good. Without the head loss calculation, you're guessing.

Zman

If you intend to run the air unit with low supply temps (condensing), be sure the air coil is sized with this in mind. No body like wind chill.
The grundfos should work fine for that application. As Jamie mentioned, you need to run the math based on equipment spec to be positive. You may need balancing valves do to the head loss differences in the zones.

doctorman

I have to study head loss a bit to understand your comments better.

but here is the Coolcalc Heat loss calculation
so around 20K for basement and 40Kbtu for the forced air
I will run the plumbing with PEX.




Cellar
Sensible BTU: 7,497 Latent BTU: 1,556 Heating BTU: 17,408

Main Floor
Sensible BTU: 10,926 Latent BTU: 2,216 Heating BTU: 23,215

Attic
Sensible BTU: 9,665 Latent BTU: 1,648 Heating BTU: 18,409

doctorman

Zman said:

If you intend to run the air unit with low supply temps (condensing), be sure the air coil is sized with this in mind. No body like wind chill.
The grundfos should work fine for that application. As Jamie mentioned, you need to run the math based on equipment spec to be positive. You may need balancing valves do to the head loss differences in the zones.

Would certainly prefer low temp supply as long as my return is under 130F.

I am installing the boiler now and will do A/C later,
Now I have Baseboard in basement and 1 st floor and attic is not heated.
so I will connect zone 2 to 1st floor baseboard till after renovation and A/C addition. I just would like to design the heating future proof so I can adopt it easily to the A/C later

EBEBRATT-Ed

Pipe sizing depends on how much water you need to move. How much water you need to move depends on heat loss and design temperature drop of the water. You have the heat loss now you need to pick a TD

The standard TD was 20 degrees. 1 gpm of water will transfer 10,000btus/hour with a 20 deg delta.
main 60,00 btu/hr=1" pipe
celler 17408=3/4 pipe
attic 3/4"
MAIN FLOOR 3/4"


30 degree td = 15,000 btus/gpm
MAIN 3/4" WOULD DO IT BUT IT'S CLOSE TO MAX 1"
CELLER 1/2"
ATTIC 1/2"
MAIN FLOOR 3/4"

40 degree td = 20,000btu/gpm
MAIN 3/4"
CELLER 1/2"
ATTIC 1/2"
MAIN FLOOR 1/2"

yOU MAY WANT TO UPSIZE IF USING PEX

SO, A LARGER TD REDUCES PIPE SIZE =REDUCED COST
BUT YOU HAVE TO USE MORE BASEBOARD AND LARGER COILS TO GET THE SAME AMOUNT OF HEAT BECAUSE YOU AVERAGE WATER TEMPERATURE DROPS.=INCREASED COST

THE LOWER THE WATER TEMPERATURE =THE MORE FUEL YOU WILL SAVE BUT THEN YOU NEED LARGER HEAT EMMITERS TO PROVIDE THE HEAT.

SO IT'S ALWAYS A COMPROMISE.

I WOULD SPLIT THE DIFFERENCE AND USE A 30 DEG TD. I WOULD DESIGN FOR A WATER SUPPLY TEMP OF 160 DEG. tHIS WILL GIVE YOU 130 DEG RETURN WATER AT FULL LOAD AT DESIGN TEMP AND YOU WILL BE ON THE EDGE OF CONDNSING. aT LOWER TEMPS WHEN YOU DON'T NEED FULL CAPACITY YOU SHOULD ALWAYS BE CONDENSING

doctorman

EBEBRATT-Ed said:

Pipe sizing depends on how much water you need to move. How much water you need to move depends on heat loss and design temperature drop of the water. You have the heat loss now you need to pick a TD

The standard TD was 20 degrees. 1 gpm of water will transfer 10,000btus/hour with a 20 deg delta.
main 60,00 btu/hr=1" pipe
celler 17408=3/4 pipe
attic 3/4"
MAIN FLOOR 3/4"


30 degree td = 15,000 btus/gpm
MAIN 3/4" WOULD DO IT BUT IT'S CLOSE TO MAX 1"
CELLER 1/2"
ATTIC 1/2"
MAIN FLOOR 3/4"

40 degree td = 20,000btu/gpm
MAIN 3/4"
CELLER 1/2"
ATTIC 1/2"
MAIN FLOOR 1/2"

yOU MAY WANT TO UPSIZE IF USING PEX

SO, A LARGER TD REDUCES PIPE SIZE =REDUCED COST
BUT YOU HAVE TO USE MORE BASEBOARD AND LARGER COILS TO GET THE SAME AMOUNT OF HEAT BECAUSE YOU AVERAGE WATER TEMPERATURE DROPS.=INCREASED COST

THE LOWER THE WATER TEMPERATURE =THE MORE FUEL YOU WILL SAVE BUT THEN YOU NEED LARGER HEAT EMMITERS TO PROVIDE THE HEAT.

SO IT'S ALWAYS A COMPROMISE.

I WOULD SPLIT THE DIFFERENCE AND USE A 30 DEG TD. I WOULD DESIGN FOR A WATER SUPPLY TEMP OF 160 DEG. tHIS WILL GIVE YOU 130 DEG RETURN WATER AT FULL LOAD AT DESIGN TEMP AND YOU WILL BE ON THE EDGE OF CONDNSING. aT LOWER TEMPS WHEN YOU DON'T NEED FULL CAPACITY YOU SHOULD ALWAYS BE CONDENSING

Thank you so much for the detailed info , I will certainly review this again and try to learn more from it.

I agree with 160F to 130F
so for the design, for now, any recommendation on the design of the system?

1 pump and 2 zone valves?
2 pumps instead of zone vlaves?
Grandfus alpha 2?

EBEBRATT-Ed

I usually use pumps but because your flow is so low I would use 1 pump with zone valves.

You probably need a buffer tank, or an indirect water heater or a dump zone to avoid short cycling

doctorman

EBEBRATT-Ed said:

I usually use pumps but because your flow is so low I would use 1 pump with zone valves.

You probably need a buffer tank, or an indirect water heater or a dump zone to avoid short cycling

buffer tank? would you please expand on that?

pecmsg

doctorman said:

I have to study head loss a bit to understand your comments better.

but here is the Coolcalc Heat loss calculation
so around 20K for basement and 40Kbtu for the forced air
I will run the plumbing with PEX.




Cellar
Sensible BTU: 7,497 Latent BTU: 1,556 Heating BTU: 17,408

Main Floor
Sensible BTU: 10,926 Latent BTU: 2,216 Heating BTU: 23,215

Attic
Sensible BTU: 9,665 Latent BTU: 1,648 Heating BTU: 18,409

Recheck your calculations. 17K for a basement on LI yet 18K for a Attic?

clammy

If installing your hot water coil in uncondition space look out for possible freezing also if using the same unit for your ac i would suggest check valves on it s loop both supply and return and if your installing a indirect for domestic hot water make sure you have chk valves on your heating s and r for the tank,The reason i say this is because i ve seen first hard thermal migration between indirects and attic hydoair system one good note is they usually never freeze is sub zero weather and the home get automatic extra de humidification durning the summer until its about 100 and the ac doesn t seem to cut it especially after showers lol .I see alot of poorly designed hydro air systems makes me sick especially since the GC usually specs them and the cheaper the better as it goes for multi million dollar homes lol .You can add a freeze stat to your hot water coil or and glycol the latter will change your pump requirements .As others have stated i would size that whole system for the lowest possible supply temp 130 to 140 max on design day .All mod con should be utilize the lowest water temps .Every mod con that runs hi temp usually lives a short hard life if your gonna run hi temp go with a cast iron boiler and save some money .The htp utf is a good boiler i heat my home w a older htp munchkin about 12 years old running 130 max at 10 oat no issues 'Design your system for low temp you wont regrett peace and good luck clammy

doctorman

clammy said:

If installing your hot water coil in uncondition space look out for possible freezing also if using the same unit for your ac i would suggest check valves on it s loop both supply and return and if your installing a indirect for domestic hot water make sure you have chk valves on your heating s and r for the tank,The reason i say this is because i ve seen first hard thermal migration between indirects and attic hydoair system one good note is they usually never freeze is sub zero weather and the home get automatic extra de humidification durning the summer until its about 100 and the ac doesn t seem to cut it especially after showers lol .I see alot of poorly designed hydro air systems makes me sick especially since the GC usually specs them and the cheaper the better as it goes for multi million dollar homes lol .You can add a freeze stat to your hot water coil or and glycol the latter will change your pump requirements .As others have stated i would size that whole system for the lowest possible supply temp 130 to 140 max on design day .All mod con should be utilize the lowest water temps .Every mod con that runs hi temp usually lives a short hard life if your gonna run hi temp go with a cast iron boiler and save some money .The htp utf is a good boiler i heat my home w a older htp munchkin about 12 years old running 130 max at 10 oat no issues 'Design your system for low temp you wont regrett peace and good luck clammy

It is so hard to find a knowledgeable person on hydronic air...

Most people who come through the door for an estimate are complete idiots who give an enormous bill and don't even know the manual J. Some tell me that I need to run my water at 190F for hydronic air, I just wanted to smack that guy and threw him out...
the fact is... these idiots will go to a homeowner that knows nothing and will get the job too.

My house hot water system is separate and runs happily for itself, not touching that.

I will get a combi boiler HTP-UFTC still to have a back up hot water for emergency cases when/if the hot water gives out.

The whole system will be in the envelope of the house in insulated and conditioned space.

doctorman

found these videos that really help me get a better understanding of hydronic air

https://www.youtube.com/watch?time_continue=2&v=UPDgVuW8NgM

doctorman

Most of these Water to air Heat exchangers do not show BTU rating for lower water temp below 180F. Is there a calculation to get the BTU for running the water on a lower temp in these or do I need a model with that BTU rating for water temp noted?

any brands or models?