Hello everyone,
I’m somewhat heat-sensitive. Until now, I have always lived in apartments that would get extremely hot in summer, despite maximizing shading during the day and ventilating strongly with rapid air exchange at night. Those were the days of my childhood spent in a basement apartment, where even in the height of summer the bedroom stayed pleasantly cool.
To get to the point: I definitely don’t want to deal with that in my own home. So, air conditioning is an important topic for me. My question is: what is the best way to maintain comfortable temperatures even in the peak of summer?
I have read that heat pumps can also provide cooling through underfloor heating, although the effect seems to be relatively mild. It’s also said that mechanical ventilation with heat recovery can be combined with cooling, but here, too, there are obviously fairly strict limitations. Finally, there is the conventional split air conditioning system, which certainly cools well but also consumes a lot of electricity. However, combined with solar panels on the roof, electricity costs should remain manageable since there is usually a surplus of electricity in summer that’s hard to use otherwise.
What would you recommend considering both cost and comfort? Maybe some combination makes sense, for example cooling with a heat pump via underfloor heating and additional cooling through mechanical ventilation with heat recovery – perhaps a moderate amount of cooling from two systems is sufficient in combination. Who has experience and can share knowledge and opinions?
Best regards,
HB1
I’m somewhat heat-sensitive. Until now, I have always lived in apartments that would get extremely hot in summer, despite maximizing shading during the day and ventilating strongly with rapid air exchange at night. Those were the days of my childhood spent in a basement apartment, where even in the height of summer the bedroom stayed pleasantly cool.
To get to the point: I definitely don’t want to deal with that in my own home. So, air conditioning is an important topic for me. My question is: what is the best way to maintain comfortable temperatures even in the peak of summer?
I have read that heat pumps can also provide cooling through underfloor heating, although the effect seems to be relatively mild. It’s also said that mechanical ventilation with heat recovery can be combined with cooling, but here, too, there are obviously fairly strict limitations. Finally, there is the conventional split air conditioning system, which certainly cools well but also consumes a lot of electricity. However, combined with solar panels on the roof, electricity costs should remain manageable since there is usually a surplus of electricity in summer that’s hard to use otherwise.
What would you recommend considering both cost and comfort? Maybe some combination makes sense, for example cooling with a heat pump via underfloor heating and additional cooling through mechanical ventilation with heat recovery – perhaps a moderate amount of cooling from two systems is sufficient in combination. Who has experience and can share knowledge and opinions?
Best regards,
HB1
H
Hausbauer14 Jul 2017 17:04Boergi schrieb:
We installed a ground source heat pump with a cooling function (additional cost 700€) and the controlled mechanical ventilation system includes a ground heat exchanger (additional cost 2,000€).
In our case, combined with shading, this is sufficient to maintain indoor temperatures even during prolonged periods of high outdoor temperatures, like recently with a maximum of 24°C (75°F).That sounds very interesting. Could you share more details about your overall system?
T
Traumfaenger4 Jul 2017 22:05Boergi schrieb:
We installed a ground source heat pump with a cooling function (additional cost $700) and the controlled residential ventilation system includes a geothermal heat exchanger (additional cost $2,000). Great! After 8 pages debating air conditioning yes or no and who has the biggest and most flashing lights on theirs, finally an alternative. Thank you! Has anyone also had experience with green roofing or something similar? Green roofing is said to provide heat protection as well (Google).
T
Traumfaenger4 Jul 2017 22:37Addendum, quote from an energy consulting brochure: "As early as the late 1980s, Kolb & Schwarz (1986) researched that a higher-quality extensive green roof significantly reduces temperature extremes on hot summer days. ... The Berlin Senate Department for Urban Development (2010) builds on this and more recent studies in its brochure ‘Concepts for Rainwater Management, Green Roofs, and Building Cooling – Guide for Planning, Construction, Operation, and Maintenance.’ It further explains that the evaporation of 1 m³ (35 cubic feet) of water generates 680 kWh of evaporative cooling, which corresponds to 0.68 kWh per liter (0.25 kWh per quart)..." (Google energy consulting opti...green).
Or simply try searching for cool green spaces online. Unfortunately, links are not allowed here.
Or simply try searching for cool green spaces online. Unfortunately, links are not allowed here.
Hausbauer1 schrieb:
That sounds very interesting. Can you tell us more about your overall solution?What exactly would you like to know?
Our building is a new construction from 2013, with 42.5cm (17 inches) Poroton masonry filled with perlite, a pitched roof with a 22° pitch, tiles, and standard insulation between the rafters.
The heat pump is a Vaillant geotherm VWS 63/3, operated with two deep boreholes of 85m (279 feet) each. As mentioned, the additional cost for the version with a cooling function was about €700. No other measures were taken.
The supply temperature on hot days is around 20°C (68°F). I think 17–18°C (63–64°F) should also work fine, but 20°C is completely sufficient for us.
On hot days, we keep the roller shutters on the upper floor about two-thirds closed, while the venetian blinds on the ground floor are tilted open. Indoor temperatures only once reached 24°C (75°F) in recent weeks; 90% of the time, they remain below 23°C (73°F).
K
Knallkörper5 Jul 2017 10:37Your constant outbursts and insults do not make your statements true. You lack a basic understanding of physics.
For the heat transfer between the ceiling and the room air, I would have assumed 6 W/(m²*K), but better values are also found in literature, so let’s assume 10 W/(m²*K). The cooling load in a typical room can reach 100 W/m² or more on hot days.
With these conservative values for a hot day, you end up with a temperature difference of 10 kelvin between the surface and the room air. If you want 22 degrees Celsius (72°F) inside the room, the ceiling must be cooled down to 12 degrees Celsius (54°F). The temperature of the cooling medium itself does not really matter for this consideration, but due to the much higher heat transfer between the piping and the ceiling material, you can expect a much smaller delta there.
Now you might argue that peak loads are buffered, that the room temperature could be allowed to rise, that there are more effective surfaces for chilled ceilings, or whatever else you can think of. All correct; then you end up with half the delta and a ceiling temperature of 17 degrees Celsius (63°F). But never 22.
What you apparently fail to understand is the fact that no thermal energy flows between two bodies that are both at 22 degrees Celsius (72°F). (Physically not entirely correct, see blackbody radiation, etc.)
For the heat transfer between the ceiling and the room air, I would have assumed 6 W/(m²*K), but better values are also found in literature, so let’s assume 10 W/(m²*K). The cooling load in a typical room can reach 100 W/m² or more on hot days.
With these conservative values for a hot day, you end up with a temperature difference of 10 kelvin between the surface and the room air. If you want 22 degrees Celsius (72°F) inside the room, the ceiling must be cooled down to 12 degrees Celsius (54°F). The temperature of the cooling medium itself does not really matter for this consideration, but due to the much higher heat transfer between the piping and the ceiling material, you can expect a much smaller delta there.
Now you might argue that peak loads are buffered, that the room temperature could be allowed to rise, that there are more effective surfaces for chilled ceilings, or whatever else you can think of. All correct; then you end up with half the delta and a ceiling temperature of 17 degrees Celsius (63°F). But never 22.
What you apparently fail to understand is the fact that no thermal energy flows between two bodies that are both at 22 degrees Celsius (72°F). (Physically not entirely correct, see blackbody radiation, etc.)
K
Knallkörper5 Jul 2017 11:02Grym schrieb:
Now he wants to cool the ceiling to 12 degrees. OMFG...
I don’t want anything, I just wanted to point out:
-that the surface temperature is physically far from 22 degrees.
-that Recknagel, like many manufacturers, does not recommend or require additional moisture regulation without reason.
Do with that what you want – you won’t be convinced by technical literature and physics; instead, you become personal, unprofessional, and offensive, so I’m bowing out here.
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