2.9. Selection of heaters and distribution of heat losses<br>

## 2.9. Selection of heaters and distribution of heat losses

Program Instal-heat&energy allows for any division of compartment heat demand into different heating methods with possibility of selection of different types of heaters in one compartment. It is possible to declare a floor heating or other receiver of thermal energy in compartment. Program does not perform floor heating calculations, but enables entering of floor heating loop efficiency calculated by means of Instal-therm or another program.

Heat distribution between various heating methods and/or to other compartments is available in project position „Building structure” in compartment edition window on the tab “Heating data”. After calculations or input of heat losses in compartment program can match in it heaters.

This is a preliminary selection, does not taking into consideration real water cooling in pipe-runs. This cooling are taken into account by the program approximately, using the multiplier depending on number of storeys. For this reason the heaters matched by means of Instal-heat&energy program can differ from heaters, which have been matched by means of program Instal-therm. For this reason it is recommended to perform exact calculations of heating system in Instal-therm program.

In field „Qexc./Φexc.” you can see the required value of heat demand, which should be supplied to compartment by heat receivers.

! Heat losses to be covered by heating „Qexc./Φexc.” are total reduced heat losses in compartment (required value of heat demand) increased or decreased by heat losses distributed to/from adjacent compartment in case of declared distribution of heat losses.

The compartment can be heated by unit heaters, radiant heating, elements with imposed resistance or by other type of heating. Depending on type of heating in compartment, the User should complete the table located on the right side of window. Program will assign heat distribution to unit heaters and the radiant heating as „Automatic”, that means, compartment heat demand will be totally covered by unit heaters. But if the project will be loaded from Instal-therm program and heat distribution between heaters and floor heating will be also “Automatic”, then after loading of project into Instal-heat&energy the priority will concern the floor heating. That means, that Qexc./Φexc. of compartment will be covered by floor heating in the scope calculated by Instal-therm program.

If the User anticipates other types of heating in compartment, he can determine their power in table as value in [W] in column „Q”/“Φ“ or as % of compartment heat demand in column „%Q” / “%Φ”. As a result required power of unit heaters in compartment will change, because the heat losses will be covered by different types of heating. The sum of individual heating powers of heat receivers will be equal to the value of „Qexc.”/“Φexc.”.

After declaring of 100% coverage of heat losses by distribution from adjacent compartment, required heaters power will be equal to 0 [W].

It is to emphasize, that the User can specify the heat division only for compartment being a recipient. It means, that division of heat is specified for heat reception direction „ Where from” and not “Where to”.

For compartment not being a heat donor „Qexc.”/“Φexc.” is automatically increased by declared value of heat stream transmitted to receiver, and field for edition of heat division is not available.

! Heat division can be declared in compartment, which does not receive heat from adjacent compartments. For such compartment „Qexc.”/ “Φexc.” will be reduced by value of heat power received from another compartment.

After entering of heat stream value in field “Qdistr”/ “Φdistr” – “Power of heat distribution from other compartments”, the User can determine here the method of heat distribution from a pop-up list and then select in table an adjacent compartment (donor) and value of heat stream covering partially or completely declared power of heat distribution from other compartments. Power of heat distribution from other compartment can be given in [W] or as its share in [%] in the value of reduced heat losses Qexc./Φexc.. In window “Method of heat distribution” the User can select following possibilities:

- Manual – makes possible individual defining of both compartments and percentage of their participation in losses coverage.

- Semi-automatic – makes possible individual defining of compartments, which will cover the heat losses of selected compartment and percentage of participation of these compartments in heat distribution will be calculated proportionally to value of total reduced heat losses of compartment.

- Automatic – program defines by itself which compartments and to which extend will cover the heat losses of actual compartment. All heated compartments adjacent to this compartment with declared internal doors in adjacent partitions are selected. All losses are distributed proportionally to the value of total reduced heat losses of specified compartment. Such method of distribution requires defining of all partitions – not only cooling partitions, but also non-cooling, so the program could automatically select compartments for distribution.

Heat distribution will be properly declared, if the sum of distributed thermal power from other compartments displayed in tab table „Heat distribution” will be equal to the value declared in field „Qdistr/„Fdistr”.

On the tab „Unit heaters” the User will complete the table of heaters selection, defining successive its symbol, power in Watt or adequately in percent of value “Qexc.”/“Φexc.” of compartment and type of heater from a pop-up list of loaded catalogues. In a window located next to the table you can see the heater’s data entered in table. Additionally the User can here complete the heater’s data with data concerning its localization in compartment, covering and method of connection to installation by means of button .

Using the button it is possible to declare requirements concerning height, width and depth of heater. More information to this contains chapter 4.3.4.

Individual heaters can have different availability status saved in catalogue, that means, available in store or on request. For this reason in selection window for each selected type of heater it is necessary to determine an availability option. As a choice we have taking over of option from “General data” or determination of availability individual for selected type of heater. It is possible to switch between these functions by means of key for loading of data from “General data” and the key for declaring of type of availability. For this second case, selecting of field “Select only available on store” means, that the heater belonging to selected type can be ordered from heaters always available on store in basic variety. Deselecting this field will mean, that the heater of selected type can be available on request.

The User can also take advantage of default type of heater defined in „Heaters selection data”. If the User has completed there data concerning location of heater in compartment, method of connection, method of covering and requirements concerning dimensions – he does not have to complete them here.

For such defined heaters in table below selection results are displayed. That are: symbol of heater, symbol of compartment, temperature in compartment, required power of heater, flow of heating agent, supply temperature, return temperature and selected type of heater, its dimensions and average adjusting of heating power of selected heater. If the heater will not be matched, in the error list appears a message informing about failed heater matching. In most cases the reason for failed matching is too small capacity of heater towards “Qexc.”/”Φexc.” or declaring of heater dimensions restriction.

Heaters are selected with consideration of coefficients correcting required heating power. These coefficients take into consideration influence of cooling of water in pipe-runs, location of heater and its shield, montage of thermostatic valve and method of connection– more information concerning selection of heaters you will find in APPENDIX B. APPLIED NORMS AND CALCULATION METHODS.