
















              *******************************************************
              *                                                     *
              *  C E N T R A L  H E A T I N G  C A L C U L A T O R  *
              *                                                     *
              *                  Version 0.2                        *
              *                                                     *
              *******************************************************


                       For the I.B.M. P.C. and compatibles.


                           Copyright D.J.Holden 1989








                                 ***>>  CONTENTS  <<***

                                                                 Page
                  Preliminaries
                       License to Copy              ..........     1
                       License to Use               ..........     1
                       Orders and Queries           ..........     2
                       General                      ..........     3
                       Provenance                   ..........     4
                       System requirements          ..........     5
                       83/84 key keyboard           ..........     5
                       Operational overview         ..........     6
                       Example files                ..........     6

                  Describing the rooms
                       The Edit screen              ..........     7
                       Returning to the Menu        ..........     7
                       Room name                    ..........     7
                       Moving between Details       ..........     8
                       Room dimensions              ..........     8
                       Room temperature             ..........     8
                       Air changes                  ..........     8
                       Floor                        ..........     8
                       Temperature across internal surfaces        9
                       Walls and Windows            ..........     9
                       Ceiling                      ..........     10
                       Moving between rooms         ..........     10
                       Changing the Heading         ..........     10
                       Deleting and Adding rooms    ..........     10

                  Radiator Selection
                       The Radiator screen          ..........     11
                       Selecting radiators          ..........     11

                  Starting a new file
                       Heading                      ..........     12
                       Number of rooms              ..........     12
                       Outside temperature          ..........     12
                       Template files               ..........     12

                  Loading and Saving
                       Loading a file               ..........     13
                       Saving a file                ..........     13
                       Saving to a remote directory ..........     13
                       Text files                   ..........     14
                       Hard vs. Floppy              ..........     14

                  Other
                       Printing                     ..........     15
                       Exposure and 'U' values      ..........     16
                       Doors                        ..........     16
                       The Full Program             ..........     17
                       Non IBM compatibles          ..........     17


                                                                      Page 1


                       ***>>  LICENSE TO COPY AND DISTRIBUTE  <<***

         This program is subject to copyright. It is not 'Public Domain'.
         You may only distribute copies of the program and associated material
         subject strictly to the following conditions:

         1.  You must include a copy of this file, the Primer file and at
             least two example files with the program.

         2.  No modifications may be made either to the program or the
             accompanying documentation.

         3.  No charge may be made for the program or documentation or for any
             additional material you may supply. A reasonable (ie. low) charge
             may be made for the media, postage, overhead etc.

         4.  This license to copy and distribute will be withdrawn from any
             individual or company that I consider is in breach of any of
             these conditions or is charging an excessive fee.

         Owing to inflation and other considerations I do not quote a maximum
         fee. If in doubt ask me FIRST. I use as my yardstick the average
         prices charged by Shareware distributors. I would appreciate the
         courtesy of distributors contacting me before adding the program to
         their library as it enables me to respond by sending updates.

                            ***>>  LICENSE TO USE  <<***

         This program is distributed as Shareware. This means that the author
         retains copyright and expects a financial reward for his efforts if
         you use the program other than for evaluation purposes. The idea of
         this is that the biggest cost in most computer software is not the
         material itself but advertising and distribution. With Shareware not
         only is this cut to an absolute minimum but you pay nothing for the
         software until you have tried it and are satisfied. If you do have
         problems you are not dealing with a salesman who has already got your
         money but directly with the programmer. With this system you are
         actively encouraged to give copies of this version of the program to
         your friends. That's the way I get new customers.

         Note that this is not the full version of the program. It has some
         features removed and certain limitations in use. Because of this I do
         not demand payment if you are using the program strictly for D.I.Y.
         or other non profit making purposes. If you use the program only in
         this way and do not need the full version and so do not wish to pay
         the full price a contribution would still be appreciated. Remember
         that even if you only use it for a D.I.Y. job the time and effort
         saved is probably worth several pounds to you.

         Other than as detailed above you may only use this program for
         evaluation and testing purposes. A time limit ot THIRTY DAYS is
         imposed for this evaluation period. If at the end of this time you
         are still using the program for commercial purposes you are obliged
         to send payment.


                                                                      Page 2



                           ***>>  ORDERING and QUERIES <<***


         The full version costs 24.00. ( Twenty Four Pounds ) inclusive.

         Please specify either 360K/5" or 720K/3.5" disc when ordering.

         I am always willing to listen to any suggestions or criticisms or to
         try to help with any problems, even if you have not paid. If you
         telephone I am normally available on weekday evenings. If you write
         please enclose an S.A.E.



                               David Holden
                               39 Knighton Park Road
                               Sydenham
                               London SE26 5RN

                               081 778 2659






             ************************************************************
             *                                                          *
             *  WHEREAS EVERY EFFORT HAS BEEN MADE TO ENSURE THAT THIS  *
             *                                                          *
             *  PROGRAM IS ERROR FREE AND PRODUCES ACCURATE RESULTS NO  *
             *                                                          *
             *   RESPONSIBILITY CAN BE TAKEN FOR THE RESULTS PRODUCED   *
             *                                                          *
             *     OR FOR ANY CONSEQUENCES OF THE USE EITHER OF THE     *
             *                                                          *
             *        PROGRAM OR OF THE RESULTS OBTAINED FROM IT.       *
             *                                                          *
             ************************************************************


                                                                      Page 3




                               ***>>  GENERAL  <<***

         The purpose of this program is to enable Central Heating Engineers to
         assess the heat requirements of a building room by room and to select
         the radiators required. Although it could be used for large buildings
         it is mainly intended for domestic or small commercial premises.

         Since I wrote the original version it has also been found useful by
         architects and others involved in construction and modification of
         buildings. Using this program is a very quick and simple way to
         evaluate the effects of the use of various insulating materials and
         techniques. This enables a rapid evaluation to be made of the likely
         cost effectiveness of the various options.

         This manual does not set out to teach you how to calculate heat
         losses. If you know nothing about the subject there is a short text
         file called PRIMER.TXT on the disc which will take you through the
         basics. This should give you enough information to enable you to make
         use of the program.

         The emphasis is placed upon speed and ease of use. Once you are
         familiar with the program you should be able to perform the
         calculations for a 3 bedroom house, select the radiators and obtain a
         print out in about 15 minutes. Not only will this seem unbelievably
         quick and easy if you have been using conventional methods, but the
         calculations are carried out using the 'proper' methods of heat lost
         through each surface, taking account of heat gained from adjacent
         rooms and heat losses through ventilation. It is therefore not only
         fast and simple it is also accurate.

         I have tried to make everything as easy and straightforward as
         possible. Once you have performed your first calculation and got the
         'feel' of the program you should find that you don't need to look at
         the instructions for normal use. There are no complicated commands to
         remember, I have tried to make everything self evident. If you are
         not used to computers don't worry. This program was written for
         people who know nothing about them.


                                                                      Page 4



                            ***>>  PROVENANCE  <<***

         Although the Central Heating Calculator is new for I.B.M. compatibles
         (July 1990) the original was written over a year ago for the Acorn
         Archimedes and shortly after for the Model 'B' and Master series. I
         have had considerable feedback from professional users and the
         present program reflects this. Many complications introduced in
         earlier versions have now been omitted and improvements made as they
         were suggested.

         The program was not written for the large company. If you employ 100
         people don't feel excluded. This is still the best for most jobs. If
         you are a larger company and like what you see but require additional
         facilities then please contact me. If there is a demand I will be
         happy to try to oblige. The program has been kept as simple as
         possible and not overburdened with confusing features. If I have
         included a feature you probably need it. If I haven't you probably
         don't. If you disagree with my judgement please tell me.

         The program is mainly aimed at the small company or self-employed
         tradesman. The price asked reflects this. No-one in business could
         possibly say that they can't afford it.

         Note that I am not a full time computer programmer. My 'day job' is
         running my own business as a Electrical Contractor, so I understand
         the problems of the small business in the building trade. I spend
         most of my days moving other peoples furniture, ripping up their
         floorboards and knocking their houses about. I spend too many of my
         evenings doing paperwork and estimates. Sounds familiar? Then this
         program is definitely for you.


                                                                      Page 5



                        ***>>  SYSTEM REQUIREMENTS  <<***


         In view of the stated aims of this program to help the small business
         I have designed it to need only the absolute minimum hardware.
         Requirements are;


            Almost any I.B.M. compatible computer.

            One (any type) disc drive.

            64K of free RAM

            DOS 2.0 or better.

            Any Mono or Colour display capable of displaying 80 column text.


         All calculations are carried out by integer multiplication and
         division for maximum speed on a machine not fitted with a floating
         point unit. This means that if you have only a basic 4.77 Mhz.
         machine or a simple laptop you don't have to wait for results as it
         still all works FAST.




                          ***>>  83/84 KEY KEYBOARD  <<***

         In following pages reference will be found to Arrow and Page Up and
         Page Down keys. On 83/84 key keyboards these are mapped into the
         numeric keypad. So that you can use the numeric keypad to enter data
         the function keys can be used instead of these keys as follows;

                  F5    is equivalent to    Up Arrow
                  F7    ................    Down arrow
                  F6    ................    Page Up
                  F8    ................    Page Down
                  F9    ................    Left Arrow
                  F10   ................    Right Arrow

         If you look at the position of these keys you will see that their use
         is perfectly logical. Anywhere in the following text that you see
         reference to the Arrow keys or Page Up/Page Down you can use these
         keys. When selecting radiators or loading files no numeric input is
         needed so the arrow keys on the numeric keypad will always work
         regardless of the setting of num-lock


                                                                      Page 6



                         ***>>  OPERATIONAL OVERVIEW  <<***

         IMPORTANT: Before you do anything make a backup copy of the program
         disc and put the original in a safe place. NEVER use the original
         disc even for a preliminary tryout.

         There are two main procedures. First you describe the rooms and then
         you select the radiators. This version uses all Imperial units,
         dimensions are in feet, temperatures in degrees farenheight and 'U'
         values in B.T.U. per sq.ft. With the full version you can choose to
         use either Imperial or Metric units.

         Describing the rooms means entering the dimensions and other details
         required. This is the most time consuming part. Note that the program
         can work only with rectangular rooms. If you have an irregular or 'L'
         shaped room you must split it into rectangular sections. As you can
         have up to 200 rooms this is no problem. It will also be found
         advantageous to break up large rooms. This will give an indication of
         the areas of greatest heat loss and therefore help you to position
         radiators to give an even temperature.

         When you have entered all the room details and the program has
         calculated the B.T.U. you can select the radiators. This version has
         the data for Barlo radiators 'built in' but the full version can use
         almost any make, including sectional cast iron or aluminium. Unless
         you intend to use Barlo radiators this section will not be of much
         practical use. It is intended mainly as a demonstration for the
         professional user.

         You can print the finished article and save it to disc. You can re
         load the file later to make changes or further printed copies. The
         printout shows details of each room with any radiators you have
         selected, the total B.T.U. for the building and the total of all the
         radiators. You can also save an equivalent of the printout to disc as
         a text file which you can load into a wordprocessor for incorporation
         into other documents.


                Example Files:

         Before trying an actual building I suggest you load one of the
         example files. This will give you some idea of the appearance of a
         finished file. Start the program by placing the disc in the current
         drive and typing 'CH <ENTER>' at the '>' prompt. When the program has
         loaded the Menu will be displayed and you can select 'Load File'. The
         screen will show a box with any Central Heating files that are
         available. Use the arrow keys to highlight one of them and press
         ENTER to load it.


                                                                      Page 7



                        ***>>  DESCRIBING THE ROOMS  <<***


                The Edit Screen:

         When you have loaded your file you will go to the Edit Screen.

         The bottom half of the screen consists of two boxes. The left hand
         box is the Detail Box. You will see a list of the various details of
         the current room down the left hand side. The right hand box is the
         Data Box. This is used to enter the data required by the program.

         The centre of the screen is made up of the Rooms Display. Each room
         takes up one line. At the left hand side is the room number, followed
         by the room name. Next come the room dimensions and the temperature.
         At the right hand side is the total B.T.U for the room. The currently
         selected room will be highlighted.

         There is space for only seven rooms in the Rooms Display so if you
         have more some will be hidden. This section of the screen will
         scroll to reveal the hidden rooms when required.

         Below the rooms display to the left is shown the outside temperature
         used and to the right is the total B.T.U. for all the rooms

         The top line shows the file Heading (more about this later).


                Returning to the Menu:

         To go back to the Menu press ESCAPE. In general pressing this key
         will quit whatever you are doing. From the Menu you can return to the
         Edit Screen at any time by selecting 'Edit'.


                Room Name:

         At first Room 1 will be selected and you will see that the first
         detail in the Detail Box is highlighted. This is the Room Name. If
         you look at the Data Box on the right hand side of the screen you
         will see the request 'Enter room name' and the flashing cursor. To
         enter a new name simply type it and press ENTER. The name in the
         Detail Box will change to your new name and the highlight will move
         down to the next detail. Note that at this stage the name in the
         Rooms Display has not changed. The Rooms Display is only updated when
         you change rooms. A room name can be up to 15 characters long.


                                                                      Page 8



                Moving between Details:

         Although the highlight will automatically move each time you enter a
         detail you can also move it using the up and down arrow keys if you
         wish to enter data in a different order, skip over a detail or go
         back and change an entry. When you reach the bottom it will 'wrap
         around' to the top and visa versa. Pressing ENTER without entering
         any data will also move the highlight down to the next detail.


                Room Dimensions:

         After the Name comes the Width, Length and Height of the room. Each
         dimension should be entered in feet to one decimal place. eg. 12ft
         6ins should be entered as 12.5


                Room Temperature:

         This is self evident. If you wish to change the temperature just
         enter a new value.


                Air Changes:

         This is the number of air changes per hour for the room. Simply enter
         a new value to one decimal place.


                Floor:

         When you reach 'Floor' the question that appears in the Data Box will
         be 'Is this the ground floor?'. If you answer 'Y' the temperature
         difference will be taken as the room temperature minus the outside
         temperature. If you answer 'N' then you will be asked to enter the
         temperature difference, (see below). When you have done this you will
         be offered a selection of materials from which to choose. If you
         don't see the one you need you can select 'Other' and enter an actual
         'U' value. When you have done this you will automatically pass to the
         next detail and you will see that the selected 'U' value has appeared
         beside the 'Floor' detail. The full version of the program enables
         you to customise all these material selection menus.



                                                                      Page 9


                Temperature across internal surfaces:

         When dealing with an internal floor, wall or ceiling you must enter
         the temperature difference. This can be a positive or a negative
         number. If the other room is warmer than the current room there will
         be a heat loss so it will be positive. If the other room is warmer
         there will be a heat gain so it will be negative. eg.

            Room Temp.        Adjacent Room Temp.      Enter Temp Diff.

               65                     70                     -5
               65                     60                      5

         If there is no difference as is the case with most internal walls
         then there will be neither loss nor gain so it is simplest to just
         skip over that surface. Most rooms will therefore require entries for
         only two or three out of the six surfaces.


                Walls and Windows:

         Walls are similar to the floor. When you move to a wall Detail you
         will see an arrow appear in the small box at the bottom centre of the
         screen. This arrow indicates the selected wall. It doesn't matter how
         this relates to the actual building but it is best to choose a system
         and stick to it. It is important to remember that the dimension
         'Width' refers to walls 1 and 3, the top and bottom walls of the box,
         and 'Length' to walls 2 and 4, the left and right walls of the box.

         When you move to a wall the first question is 'Is this an outside
         wall?'. If you answer 'Y' the temperature difference will be taken as
         the room temperature minus the outside temperature. If you answer 'N'
         then you will be asked to enter the temperature difference. After you
         have selected the material if it is an outside wall you will be asked
         if the wall has a window. If you answer 'Y' you will be asked for its
         Width and Height. When you have entered the window dimensions (to one
         decimal place) you will be asked if there is another window. If you
         answer 'Y' you will be asked for its Width and Height and so on until
         you have entered the dimensions of all the windows.

         When you have entered the window dimensions you will be asked to
         select the glazing material. Once again you can enter an actual 'U'
         value if you wish. It only possible to select one glazing material
         for all the windows but it is most unusual in practice to find a
         mixture in one wall.


                                                                      Page 10


                Ceiling:

         The ceiling is similar to a wall. The question 'Is this the roof?' is
         equivalent to asking if it is an outside wall. Skylights are dealt
         with in a similar manner to windows except that only one skylight is
         permitted. This doesn't mean that you can't have more than one, you
         will just have to do a bit more work.

         There are two alternatives. If you have two skylights 2ft by 3ft you
         could enter Width as 4ft and Length as 3ft. Alternatively (or if they
         do not have a dimension in common) you can calculate the areas and
         enter the total area as one dimension and '1' as the other.


                Moving between rooms:

         You can move between rooms at any time by pressing Page Up or Page
         Down. As you change rooms the highlight will move to the new room and
         the data shown for the old room will be updated to reflect any
         changes made. The total B.T.U. will also be updated. If you press
         Page Up when you are on the top room of the display or Page Down when
         you are on the bottom room the Rooms Display will scroll to make the
         next room visible.


                Changing the Heading:

         If you wish to alter the heading you can do this from the Edit
         Screen. If you press CTRL-H the heading will be highlighted and the
         cursor will move to the start of the heading line. The end of the
         heading line will be shown by a left pointing arrow character. This
         is done to display any 'trailing spaces'. When the heading is printed
         it will be centered on the page so if you wish it to be offset to the
         left hand side of the page you can add spaces after the text.

         You can move backwards and forwards along the line with the arrow
         keys and Ctrl-Left or Ctrl-Right will move to the start and end of
         the line respectively. Type in any new text, which will be inserted
         into the line at the cursor position. You can delete letters with
         either the Delete key to delete forwards or the Backspace key to
         delete backwards. When you are satisfied press either ESCAPE or ENTER
         to return to entering the room details.


                Deleting and Adding rooms:

         The number of rooms is not fixed at your first choice but can be
         changed at any time from the Edit Screen. To ADD a room below the
         currently selected room press either '+' key. Deleting a room is
         deliberately made slightly awkward to avoid accidentally wiping out
         data. To wipe out the current room you must use the two key command
         CTRL-D, CTRL-R (DR=Delete Room). This means hold down the CTRL key,
         press and release 'D' then press and release 'R'. The selected room
         will disappear and the total B.T.U. will be adjusted. Unless the
         deleted room was the last room the new selected room will be the one
         below the deleted room.


                                                                      Page 11



                          ***>> RADIATOR SELECTION <<***


                The Radiator Screen:

         When you choose 'Select radiators' from the Menu you go to the
         Radiator Screen. Highlighted at the top left is shown the name and
         B.T.U. required by the current room. This will be the first room at
         this stage. At the top right is shown the total output of radiators
         selected. Below this are shown any selected radiators, their type
         (DP, SP, etc.), height, width and the output for each. You can have
         up to four radiators for each room.

         Below this is the data for the radiators used. In this version of the
         program this will be 'Barlo'. The full version can load files created
         from almost any manufacturers data sheets.

         The radiator data is laid out in a similar manner to that used by the
         data sheets. Down the left hand side of the screen are shown the
         radiator lengths. At the top is the manufacturers name and below this
         the heights available, for Barlo these are 16,20,24 and 28 inches,
         duplicated for each type. Next are the types available, in this case
         SP (Single Panel), SP Con (Single Panel Convector) and DP Con (Double
         Panel Convector). Below this are the columns of individual radiator
         outputs.


                Selecting Radiators:

         To select a radiator move the highlight to the one you require with
         the arrow keys and press ENTER. Any previously selected radiators
         will be wiped out and replaced by the new one. If you want more than
         one then press either '+' key instead of ENTER and the chosen
         radiator will be ADDed to any already selected.

         Each room can have up to four radiators. If the room is large enough
         to need more than four it would probably be better to split it into
         two or more sections so that you can get a better idea of the of the
         heat loss distribution over the room.

         Moving between rooms is done with the Page Up or Page Down keys.


                                                                      Page 12



                           ***>> STARTING NEW FILES <<***

         So far I have assumed that you are using one of the example files. To
         create your own select 'Start new file' from the Menu.

         If you have previously loaded a file and changed it in any way you
         will be asked 'Are you sure?'. You must answer 'Y' to this prompt.
         Pressing any other key will make the program give up and return to
         the Menu. This prompt is used whenever you select a function which
         will cause a file which has been changed in any way to be replaced by
         a new file.


                Heading:

         The screen will clear and you will be asked to enter a Heading. This
         is a single line of text which will appear at the top of any printed
         copy. Normally this would be the address of the building. The heading
         can be up to 76 characters long. You can change the heading later if
         you wish.


                Number of rooms:

         Next you will be asked for the number of rooms. You can enter any
         number up to 200. If you just press ENTER at this point a default
         number will be assigned.


                Outside Temperature:

         You will next be asked for the outside temperature. If you just press
         ENTER a default value of 30 deg. (ie. two degrees of frost) will be
         assumed.

         Once you have entered the number of rooms you will go to the Edit
         screen. The main difference this time is that most of the fields in
         the Rooms Display will be zero as you haven't yet entered any data.


                Template files:

         It sometimes happens that you have a number of buildings which are
         almost identical, for example on a housing estate. You can save time
         by making a 'template' file which has all the basic details of the
         buildings. You can then load this file and change only the parts
         which are different, saving it with a new name.


                                                                      Page 13



                           ***>> LOADING AND SAVING <<***


                Loading a file:

         To load a file select 'Load file' from the Menu. If you have made
         changes to a file already loaded you will be asked for confirmation
         before proceeding. A box will then appear on the screen showing all
         the Central Heating files available on the current drive and
         directory. Use the arrow keys to highlight the file you want and
         press ENTER. Pressing ESCAPE will exit without loading a file and
         return you to the Menu.

         After a successful load you will go directly to the Edit screen.


                Saving a file:

         To save your data select 'Save file' from the Menu. You will see a
         similar box to the Load option showing all the Central Heating files
         on the current drive and directory. At the bottom of the screen is a
         box for you to enter a filename. If the file already has a name, ie.
         if you have Saved or Loaded it before, this will be offered in this
         box. If you press just ENTER the file will be saved with this name.
         To enter a new name just type it and press ENTER. There is no need to
         delete the old name.

         If you press ESCAPE you will return to the Menu without Saving your
         file. Pressing just ENTER when no existing name is offered will also
         return to the Menu without Saving your file.

         If a file of the same name already exists you will be asked for
         confirmation before overwriting it.


                Saving to different drive/directory:

         Normally all files are saved to the current drive and directory but
         it is possible to save a file to a different directory by adding a
         drive and/or directory prefix to the filename. For example to save
         your file to drive B, directory 'OLD' you would enter at the prompt

                        B:\OLD\<filename>

         where <filename> is the actual name of the file.



                                                                    Page 14



                Text files:

         This option will create a disc file which is the equivalent of the
         output sent to the printer. The only difference is that the disc file
         will have no page breaks. The main use for this is so that you can
         load the file into a wordprocessor and modify it or incorporate it
         into other documents such as a job specification or estimate.

         When you select this option you will be asked for a filename. You can
         use a drive or directory prefix and also add a file extension if you
         wish. If you do not use a drive or directory prefix the file will be
         saved to the current directory. If you do not add a file extension
         the file will be saved with the extension .TXT

         It is important to remember that a file saved in this way CANNOT BE
         RE-LOADED INTO THIS PROGRAM. You must also save your file in the
         'normal' way. You will not be warned if you are replacing a file of
         the same name as it is assumed that all Text files can be re created
         from the normal Central heating files if they are accidentally
         overwritten.


             Hard vs Floppy:

         You can run this program from either hard or floppy discs. I would
         suggest that as the program makes only infrequent disc access and the
         files are normally short there is little advantage to be gained from
         using a hard disc. The program itself is small and most files will
         only be about 4K long so even a 360K floppy will probably contain
         more files than you can conveniently manage before it is full.

         The suggested method is to start a new disc after a set period of
         time, copying the program onto each new disc. The time covered by
         each disc will vary according to your turnover from a week for a
         large company to 3 months or even a year for a single tradesman.

         This method makes it easy to find the file you want by simply picking
         up the correct disc for the required period. It also solves the
         Backup problem because your records are all on floppies and you can
         easily keep backups of the current disc(s).


                                                                      Page 15



                              ***>> PRINTING <<***

         To print a file select the 'Print' option at the Menu. The screen
         will clear and you will be prompted to press SPACE when your printer
         is ready. Pressing ESCAPE at this point will return you to the Menu.
         Pressing 'P' will set 'Paged' mode (see below).

         To stop printing at any time hold down the ESCAPE key.

         No printer Reset is sent before printing begins. This allows use of
         any 'front panel' controls or a separate printer setup program to set
         your printer to a specific font etc. This means that if you have been
         using your printer earlier it may have some features left active by
         other software. The most likely symptom of this is only a few lines
         being printed before the printer moves to the next page. If in doubt
         switch the printer off and on again to reset it before printing.

         If your file has more than about dozen rooms or more than one
         radiator in most of the rooms you will find that it will be split
         into pages. This is done by sending a Form Feed command when there is
         not enough space for the next room at the bottom of the page. This
         assumes that you are using 11 inch continuous or 'fanfold' paper. If
         you use individual sheets you will want the printer to pause at the
         bottom of each page so that you can insert a new sheet of paper. To
         make this happen instead of pressing SPACE when requested to at the
         start of printing press 'P'. The computer will stop when it reaches
         the end of each page, giving a 'beep' and a message to warn you, and
         will not continue until you press the SPACE bar.

         This option can be made the default on the full program and it is
         also possible to change the page length and number of lines left
         blank at the top and bottom of each sheet.



                                                                      Page 16



                       ***>> EXPOSURE AND 'U' VALUES <<***

         No allowances have been made for Exposure or Ground Effect in this
         program. This omission is deliberate. 99% of the time in modern
         housing these effects are minimal. On the few occasions where they
         will be significant you can easily allow for them by modifying the
         'U' value of exposed surfaces. If you are unsure of what allowance to
         make you would probably be liable to misuse any feature that I
         included in the program. Similarly the 'U' values I have chosen for
         the various materials are average values. In the full version you can
         easily change them if you disagree with my choice.

         This decision is by no means irrevocable. I am always happy to listen
         to comments, good or bad, and will change the program if users wish.



                              ***>> DOORS <<***

         You may have noticed that doors don't seem to exist in this program.
         This is not an oversight. An earlier version made allowance for doors
         but the feature was removed after trials.

         Textbooks seem to assume that all internal doors will be kept firmly
         shut and that rooms will be at different temperatures. This may have
         been true in the days of coal fires but if you walk into a modern
         centrally heated house you are unlikely to find ANY door shut except
         possibly an occupied bathroom or bedroom. Pretending that internal
         walls have any effect under these circumstances is not realistic.

         Doors in external walls can have an effect. The largest effect is
         caused by cold air entering the building, whether from draughts or
         the door being opened. This is dealt with by adjusting ventilation.
         The cause of most cold hallways and landings can be traced to
         inadequate allowance here. Glazed doors can simply be treated as
         windows. Solid or part glazed doors can be treated as windows with a
         suitably adjusted 'U' value.



                                                                      Page 17


                            ***>> THE FULL PROGRAM <<***

         The main limitation with this version is that you can only use
         'Barlo' radiators. With the full program Radiator files are loaded
         and saved just like Central Heating files. There is a facility within
         the program for you to create your own Radiator files from almost any
         manufacturers data sheets and you can also decide which make of
         radiator will available when you start the program.

         You can choose to use either Imperial or Metric units. You can also
         set the various defaults used in the program, outside temperature,
         default air changes, room temperature and number of rooms when
         starting a new file and the page layout used when printing.

         You can design all your own Material Selection menus and define the
         'U' values assigned to each selection. This enables you to customise
         the program to suit the types of structures you normally work with.


                    ***>> NON I.B.M. COMPATIBLE MACHINES <<***

         Versions of this program are already available for Acorn Archimedes
         and Model B/Master. The Archimedes version is file compatible with
         the PC version and files can be exchanged via the Archimedes PC
         Emulator or a file transfer program such as !PCDir. The Model
         B/Master program uses a more compact file format because of the
         limited memory on these models so files are not interchangeable but a
         conversion program is available. Any future versions are expected to
         conform to the PC/Archimedes format to ensure easy file transfer from
         one machine to another.

         The PC version works perfectly well and acceptably fast under the PC
         Emulator on the Archimedes. I see no reason why it should not also
         work on other computers which can emulate a PC such as the Amiga,
         Master 512, etc. If you find that it does work in this way on your
         machine please tell me so I can pass on the information to others.

         The screen layout and user interface is similar on all machines,
         bearing in mind the differences and limitations of each type. This
         will be maintained in any future versions so that once you have used
         the program on one make of computer you should find only minor
         differences when changing to another.

         If you like what you have seen or read and don't have one of these
         computers then don't despair. If I think it worthwhile (ie. if enough
         people want it!) I will write a version for your machine. By the time
         you read this it may already exist. Please write or phone and ask me.

         For this and any other comments and suggestions please contact;

                            David Holden
                            39 Knighton Park Road
                            Sydenham
                            London SE26 5RN

                            081 778 2659



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