Heat Loss Calculator

PLEASE USE ONLY THE CALCS. BELOW THAT APPLY, THE HEATLOSS CALCULATOR
WILL ASSUME ALL THE OTHER CALCULATIONS AS "ZERO"
Measurement systems :  Calc. 1
> Please note that the default measurement system is "metric" , but you may also choose "imperial system"
Measurments System
Name of the room
 
Room Location : Calc. 2
> Name the room that you are calculating the heatloss of;  i.e. bedroom, dining room, utility room  etc.
> Room location, choose from the available options and enter room height and the floor area of room
> If it is attic room with sloping walls and ceiling, there are endless permutations to such rooms, for a rough assesment, we suggestyou take and average height and treat it as normal room.
Floor Level of Room
Room Height (in metres)
Floor Area (square metres)
 
Outside Walls I : Calc. 3
 If all your walls and windows are of same type, then just measure entire length of outside walls including windows and any outside doods in this section and ignore the section "Outside Walls II" , if you are doubtful about the wall type choose "solid"
> please enter zero if it is internal room/party walls only - no outside walls  and also ignore Calc 4
Outside Wall Type
Lenght of outside wall(s) in metres
Window Type
Area of window(s) in square metres
 
Outside Walls II : Calc. 4
Please fill out this section ONLY if you have two different type of walls (cavity, solid etc) and/or two different type of windows (double and single glass) - use double glass if it is triple glazed etc.
Outside Wall Type
Lenght of outside wall(s) in metres
Window Type
Area of window(s) in square metres
 
All window walls : Calc. 5
in case all walls are window calc 3 and/or calc 4 are ignored
All window walls
Window type
Area of window in square metres
 
Party walls / Internal walls : Calc. 6
The heatloss calculator assumes that party walls and internal walls have heated rooms on the other side.
Lenght of wall in metres
 
Variations : Calc. 7
Fan extraction
Outside temperature (in Centigrade)
Desired room temperature (in Centigrade)
   
Ceilings without Insulation for Top Floors and Single Storey Buildings : Calc. 8
The Heatloss Calculator assumes that ceilings on top floors and single storey buildings are insulated. If not insulated please tick "no"
Ceiling insulation
   
Floors with insulation: Calc. 9
The Heatloss Calculator assumes that floors in Basement/Ground Floor rooms and Single Storey buildings are not insulated, if they are insulated please tick "yes"
Floor insulations
 
Velux / skylight : Calc. 10
Window Type
Area of Windows in square metres
   
Northern aspect room: Calc. 11
Please tick "yes" if room is facing the north 
Northern aspect room?
 
Other operating temperatures : Calc  12
The system assumes the temperatures  according to EN 442 which is 75C inlet, 65C outlet and 20C room temperature, please enter the operating temperatures in C.
Flow (inlet) water temperature
Return (outlet) water temperature
   
Heatloss Calculator assumes following data

> Steady state heatloss principle
> Installation complies to BS5449
> Temperature variations
    External walls, floors and ceilings : 22C
    Internal floors : nil
    Internal ceilings : 5C
    Internal walls : nil (15C when unheated other side)
    Party walls : nil (15C when unheated other side)
    Windows/skylights : 22C
 
> Air Changes 2 per hour
 
> U values
   Air charge rate : 0.66
   Insulated external floor : 0.4
   Uninsulated external floor : 0.8
   Insulated external ceiling : 0.4
   Uninsulated external ceiling : 2.0
   Internal ceiling : 1.7
   Party wall : 1.7
   External wall: solid :2.1, cavity:1.5, insulated:0.5
   Single glass window : 5.0
   Double glass window : 2.5
   Sigle glass skylight : 6.8
   Double glass skylight : 4.0
NOTES

(i) If in doubt about Wall Type use 'solid'
(ii) Measure entrie lenght of outside wall(s) including windows and any outside doors



(iii) Include any glass doors