Hello,
The plan is to install an air-to-water heat pump in a split system configuration.
The outdoor unit is to be located about 10 meters (33 feet) away from the indoor unit (control room). Since the concrete slab has not yet been poured, the question is whether the connecting lines between the outdoor and indoor units should be laid in or beneath the slab right away, or at least have the necessary preparations made (empty conduit) — which would also be the shortest route.
Now my questions:
1.) When filling with refrigerant above a certain "critical amount," an annual leak test is required. (Currently, there is no information on the theoretical amount of refrigerant needed.) -> What implications would this have for routing the lines in or under the slab? Alternative: glycol filling?
2.) What are the material requirements for the lines (plastic, metal)?
3.) What about insulation? On one hand, to address the dew point (condensation formation), and on the other, to prevent potential heat losses, especially during defrosting or ice removal of the outdoor unit.
4.) How would insulation generally affect the efficiency of the heat pump? (Would routing the lines in or under the slab be comparable to a ground-source heat pump using a brine system?)
Thanks for your experiences.
The plan is to install an air-to-water heat pump in a split system configuration.
The outdoor unit is to be located about 10 meters (33 feet) away from the indoor unit (control room). Since the concrete slab has not yet been poured, the question is whether the connecting lines between the outdoor and indoor units should be laid in or beneath the slab right away, or at least have the necessary preparations made (empty conduit) — which would also be the shortest route.
Now my questions:
1.) When filling with refrigerant above a certain "critical amount," an annual leak test is required. (Currently, there is no information on the theoretical amount of refrigerant needed.) -> What implications would this have for routing the lines in or under the slab? Alternative: glycol filling?
2.) What are the material requirements for the lines (plastic, metal)?
3.) What about insulation? On one hand, to address the dew point (condensation formation), and on the other, to prevent potential heat losses, especially during defrosting or ice removal of the outdoor unit.
4.) How would insulation generally affect the efficiency of the heat pump? (Would routing the lines in or under the slab be comparable to a ground-source heat pump using a brine system?)
Thanks for your experiences.
Hello,
I’m not an expert, but I’ll share my experience with you:
- We had two PVC drainage pipes installed, through which the refrigerant lines were routed.
- The pipes start in the utility room, run under the garage slab, and end behind the garage.
- Only the refrigerant lines are insulated. They are wrapped in black insulation.
Important: Both ends of the PVC pipes were open in our case, and on Christmas Eve we ended up with a rat in the utility room. That was quite an experience! Rainwater partially washed out the PVC pipe, and that’s how the pest got inside.
If you use PVC pipes, be sure to seal the outside ends right away.
Best regards, torsan
I’m not an expert, but I’ll share my experience with you:
- We had two PVC drainage pipes installed, through which the refrigerant lines were routed.
- The pipes start in the utility room, run under the garage slab, and end behind the garage.
- Only the refrigerant lines are insulated. They are wrapped in black insulation.
Important: Both ends of the PVC pipes were open in our case, and on Christmas Eve we ended up with a rat in the utility room. That was quite an experience! Rainwater partially washed out the PVC pipe, and that’s how the pest got inside.
If you use PVC pipes, be sure to seal the outside ends right away.
Best regards, torsan
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