Installations for heating and cooling

How should I choose the highest and lowest level of input building?

Choice of level depends on how open it is between different floors. Levels for each building component to be counted from the lowest floor level in the contiguous room volume. Office building can in many cases be contiguous in many floors while residences are always separated by floor separation joists.

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Why should I add internal building parts?

Internal components affect the calculation in two ways.

Internal construction parts store heat at temperature fluctuations and for direct solar radiation solar heat is stored even if the air temperature is not changing.

The program builds up a model with energy exchange between the interior walls and siding.

When there is a temperature difference between different surfaces there is a radiant Exchange.

It can be said that interior walls pick up heat through contact with ambient air and radiates the heat to exterior walls. The larger the indoor wall area, the greater the surface contact between the indoor and exterior walls.

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How do I choose the thermal power share in floor heating system

The thermal power share refers to power to be delivered to room air. Each building part has its share, which can be proportional to the construction part of the area but it can also be dependent on other factors.

One can divide into rooms with different power requirements.

In two storey villas, it is not unusual that floor heating in the lower store also may take some of the power requirements of the upper level. The internal reallocation depends on how open the floor plan is. With a very open floor plan, you can transfer up to 50% of the power requirements of the upper floor to the ground floor.

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How to simulate hot electric heated glass?

If you just keep room temperature on the inside of glass you can reduce heat resistance of glass with internal heat of transfer. If you heat with glass, which is less successful, one can simulate the thermal properties of glass as a 1 d building part with thermal layer that takes its share of power requirements.

The window is described only with optical characteristics without U-factor. The model is not accurate but gives a good approximation.

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How do you use VIP-Area for multi-zone calculation?

You save a VIP Area-file for each zone.

Why do I get the lower energy usage when I raise the minimum temperature of the supply air?

Usually gives increased supply air temperature increased energy then supply air is heated in spite of the fact that the room temperature is higher than the requirement.

But if the supply air temperature is achieved mainly by increased heat recovery it causes an increased use of recovery. It results in increased room temperature over minimum level. The heat stored in the building and heating other time decreases.

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How to calculate natural ventilation.

When it comes to energy calculation, it is usually most appropriate to adopt that ventilation requirements are achieved regardless of the system type. It is usually less interesting to note that energy savings is achieved by not fulfilling the ventilation requirements.

It is calculated with exhaust air ventilation. Power to the fan is set to zero by setting fan pressure to zero.

Complement with fresh air vents so that the internal negative pressure is set at levels that can be operated with natural ventilation IE max 5-10 Pa depending on chimney height.

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How do you handle airing?

In Sveby data input guide for residential project there are different suggestions on how to handle the airing.

We recommend adding a little air flow in addition to normal ventilation.

A ventilation unit can be called "Airing" where to place airing ventilation flows for supply and extract.

We advise against an energy supplement. It can never be "right" because it does not take into account solar collectors, heat pumps or a number of other factors that affect energy use.

How to simulate a Crawl Space.

In most cases, a crawl space can be calculated as slab on grade. Although it is fresh air ventilated so is the ventilation is usually rather limited. To be more precise the crawl space is calculated as a separate zone. The temperature requirements are set widely enough to get no heating or cooling. Add fresh air vents.

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How to simulate an exhaust air ventilated crawl space.

Calculate the space as a separate zone. Insert a ventilation unit and put the building's exhaust fan as supply air fan in crawl space zone to get the heat from the fan to the crawl space.

Exhaust air from the crawl space is simulated according to actual performance with or without fan.

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How do I change the language in VIPS-Energy?

Click at code/language under menu choice “Input”.

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