ᐅ Cooling in summer with an air-to-water heat pump, underfloor heating, and/or a ventilation system?
Created on: 21 Apr 2018 16:39
A
AnNaHF79
Hello,
currently, the installation of an air-to-water heat pump, underfloor heating, and a ventilation system from PLUGGIT is planned for our single-family home.
Now that temperatures are pleasantly rising, it is already getting quite warm in our current older building. Of course, the single-family house will (hopefully) be better insulated and proper shading will be provided, but due to the large glass surfaces, it could still become very warm in the summer.
We are now considering whether we should also provide air conditioning; there seem to be several options:
a) Installation of a different reversible air-to-water heat pump; cooling would then be provided via the underfloor heating system. It is not entirely clear to me how much cooling can be achieved this way, and a condensation sensor is probably mandatory.
b) Installation of the ventilation system with a ground source heat pump to supply cooler fresh air.
c) Adding a dedicated air conditioning unit before the ventilation system?
d) Installation of a “real” air conditioning system along with fan coil units.
Option d) is excluded due to cost; do options a), b), or c) offer anything useful and can be added for a “small” additional cost? a) and b) appear to be the most practical...
For b), PLUGGIT also offers appropriate solutions (products: SWT180 and GTC); not sure about cost/efficiency.
For a), Stiebel probably has corresponding options; also unknown cost/efficiency. The main concern here is that it might only create a “cold spot” on the floor but not actually cool the room in general.
Any opinions?
Thanks.
currently, the installation of an air-to-water heat pump, underfloor heating, and a ventilation system from PLUGGIT is planned for our single-family home.
Now that temperatures are pleasantly rising, it is already getting quite warm in our current older building. Of course, the single-family house will (hopefully) be better insulated and proper shading will be provided, but due to the large glass surfaces, it could still become very warm in the summer.
We are now considering whether we should also provide air conditioning; there seem to be several options:
a) Installation of a different reversible air-to-water heat pump; cooling would then be provided via the underfloor heating system. It is not entirely clear to me how much cooling can be achieved this way, and a condensation sensor is probably mandatory.
b) Installation of the ventilation system with a ground source heat pump to supply cooler fresh air.
c) Adding a dedicated air conditioning unit before the ventilation system?
d) Installation of a “real” air conditioning system along with fan coil units.
Option d) is excluded due to cost; do options a), b), or c) offer anything useful and can be added for a “small” additional cost? a) and b) appear to be the most practical...
For b), PLUGGIT also offers appropriate solutions (products: SWT180 and GTC); not sure about cost/efficiency.
For a), Stiebel probably has corresponding options; also unknown cost/efficiency. The main concern here is that it might only create a “cold spot” on the floor but not actually cool the room in general.
Any opinions?
Thanks.
T
Traumfaenger28 Jul 2018 00:25We have an air-source heat pump with reversible operation for heating and cooling. However, the manufacturer requires a connection between the outdoor and indoor units using suitable refrigerant lines. This would cost us about 1000 EUR. We have now decided on green roofing. It costs a bit more upfront but is cheaper in maintenance and operation. Additionally, there are municipal incentives, the sealed surface area is smaller, and temperature differences of up to 7°C (13°F) can be achieved.
Just google "BERLIN Senate Department for Urban Development (2010)" and their brochure "Concepts of Rainwater Management. Green Roofing, Building Cooling. Guide for Planning, Construction, Operation, and Maintenance." It clearly explains that the evaporation of 1 m³ (35 cubic feet) of water generates evaporative cooling of 680 kWh. The annual evaporation capacity of extensive green roofs is based on retaining 60 - 80% of annual rainfall, which evaporates with an energy consumption of 2670 kJ per m² (0.25 kWh per square foot). The effect of evaporative cooling can be further improved by irrigating the roof. As a rule of thumb, about 3-5 mm (0.12-0.20 inches) per square meter evaporates daily. This means that with just 3 mm (0.12 inches) of evaporation, 300 liters (79 gallons) of water evaporate on 100 square meters (1076 square feet) of roof or facade area. This corresponds to an energy release of 200 kWh per day. Producing this cooling with typical air conditioning systems would cost about €20.00 per day at current average electricity prices.
Just google "BERLIN Senate Department for Urban Development (2010)" and their brochure "Concepts of Rainwater Management. Green Roofing, Building Cooling. Guide for Planning, Construction, Operation, and Maintenance." It clearly explains that the evaporation of 1 m³ (35 cubic feet) of water generates evaporative cooling of 680 kWh. The annual evaporation capacity of extensive green roofs is based on retaining 60 - 80% of annual rainfall, which evaporates with an energy consumption of 2670 kJ per m² (0.25 kWh per square foot). The effect of evaporative cooling can be further improved by irrigating the roof. As a rule of thumb, about 3-5 mm (0.12-0.20 inches) per square meter evaporates daily. This means that with just 3 mm (0.12 inches) of evaporation, 300 liters (79 gallons) of water evaporate on 100 square meters (1076 square feet) of roof or facade area. This corresponds to an energy release of 200 kWh per day. Producing this cooling with typical air conditioning systems would cost about €20.00 per day at current average electricity prices.
Then you will need an irrigation system. It is so dry that there is nothing to evaporate.
What about structural engineering? A roof like that weighs quite a bit.
How is the maintenance?
What about unwanted plant growth? Considering what grows in my stone garden in just one year, the oat harvest was surprisingly good.
How is it in winter? Does it also provide cooling?
Does it increase the snow load?
I think the idea of green roofs is not bad. We once considered it for the garage at the very beginning.
What about structural engineering? A roof like that weighs quite a bit.
How is the maintenance?
What about unwanted plant growth? Considering what grows in my stone garden in just one year, the oat harvest was surprisingly good.
How is it in winter? Does it also provide cooling?
Does it increase the snow load?
I think the idea of green roofs is not bad. We once considered it for the garage at the very beginning.
I am cautious about green roofs... Considering what roots are capable of lifting and penetrating, I actually don't want that on the roof. No matter how many times special layers claim to offer "root protection." We had a shoot that broke through a 100mm (4 inch) thick asphalt layer from underneath over several years. They can tell me a lot about root protection and so on.
I'll join in here. Unfortunately, we have to green our flat roof at least extensively.
Now the question for me is whether it’s still worth investing extra money to make the heat pump reversible, if a green roof is supposed to provide that much cooling.
The plan is for a ground source heat pump with a horizontal collector.
Now the question for me is whether it’s still worth investing extra money to make the heat pump reversible, if a green roof is supposed to provide that much cooling.
The plan is for a ground source heat pump with a horizontal collector.
If you have a ground-source heat pump, I would consider using it for cooling since it essentially operates at no extra cost—you only need electricity to run the pump, and the cold water comes for free.
The roof should provide significantly more than just ground cooling; I’ve read that an approximate 2°C (3.6°F) temperature difference can be achieved with optimal passive cooling.
In a summer like this one, I would definitely be willing to pay extra for those additional 2°C (3.6°F).
The roof should provide significantly more than just ground cooling; I’ve read that an approximate 2°C (3.6°F) temperature difference can be achieved with optimal passive cooling.
In a summer like this one, I would definitely be willing to pay extra for those additional 2°C (3.6°F).
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