Mid Sweden University

This is a theoretical study based on the theory of collective goods from microeconomics. If a MU-dwelling building have supply water temperature control SWTC and heat metering HM the collective indoor temperature will be 21.7 degrees C. If two identical buildings share HM and both have their own SWTC then the indoor temperature in both buildings will be 22.5 degrees C since the marginal cost of temperature for the collectives is halved. If the two buildings have less than 15 dwellings each one HM and one SWTC can be used for both buildings. The difference in temperature between the buildings will probably be less than 1 degrees C. If they are bigger it is profitable to invest in one HM and one SWTC for each building to avoid the low indoor temperature from the unbalance in heat demand.

The heat use in individually heated dwellings is reduced if the dwellings are put together in MU-dwelling buildings. It is not the insulation that is changed it is the balance temperature that is increased. The balance temperature is the temperature in a dwelling with closed heaters. The cost for the building and the used heat at a temperature increase in a dwelling is the heat loss out. It is optimal or it gives the highest standard of living if the marginal cost of temperature is for the heat loss out. This is possible if the measured heat to a dwelling is reduced with the variable part in a two part tariff. The rest of the cost of heat is covered with the fixed part. This is important if individual heat cost allocation is used.

The paper study the economy of improvements in the heating system and in a building in Lithuania and introduces the use of the cost of cold in heating calculations. A reduction in the cost of cold is the value of an increased indoor temperature. Supply water temperature control in the building eliminates the cold periods before and after the heating season. This reduces the cost of cold. Additional insulation both reduces the cost of cold and the cost of heat. Individual heat cost allocation reduces the cost of cold since every household can chose the temperature they are willing to pay for, if the heat transfer between the dwellings is compensated. The cost of cold is higher at the high price of heat ph = 45 EUR/MWh. Better economic data is necessary to draw definite conclusions about the economy.

The paper studies how the heat transfer between the dwellings increases the cost of an indoor temperature increase. The cost increase makes the households chose a lower indoor temperature that give inconveniences with a value many times higher than the positive value of individual heat cost allocation it self A two part tariff with a division into a fixed and a variable part reduces the cost of a temperature increase. The cost should be the same as for only the heat loss to the outdoor air since heat transferred to other dwellings is not used. The cost of an increase also depends of the fixed losses in the heating system. A fixed part between 0.3 and 0.5 gives in best case an inconvenience two times higher than the positive value of heat cost allocation. The fixed part must be calculated for every dwelling separately.

The demanded indoor temperature in Swedish dwellings can be expressed as a function of the marginal cost of indoor temperature and of the disposable income of the household. The function shows that the temperature in multiple unit dwellings is higher than in singel unit dwellings. The indoor temperature increases with increasing disposable income. The function can also be used to prognosticate the indoor temperature at given economic conditions, but moore data are needed to check the validity.

This is an economic analysis of indoor temperature and of short changes in indoor temperature. The loss of benefit is higher during short involuntary changes than during a voluntary chosen indoor temperature. There will be a short involuntary change in the indoor temperature if the design heating capacity doesn’t cover the heat demand during a cold period. A one-day cold period is to short for design of heating capacity. The loss of benefit from low temperatures during one day will not be so high that it motivates a heating system. The increase of loss of benefit during short involuntary changes in indoor temperature may be 10 times higher than during voluntary changes, if the present Swedish design rules for heating capacity are economically optimal. The loss of benefit at the indoor temperature 22degreesC is 0.2 % of the disposable income per day of heating season. If the temperature is voluntary changed to 20degreesC the loss of benefit will be 0.9 %. A short involuntary change to 20degreesC will increase the loss of benefit to 3.1 %.

This is a theoretical study on how to improve the optimisation of the all-air system. The economizer cycle was designed to distribute heat and cold with the supply air. To reduce the investment in heating and cooling capacity the outdoor air rate was reduced to the minimum outdoor air rate during high and low temperatures. This was as close to the economical optimum as possible with the control equipment available in the 1920-thies. An improved optimisation gives that the optimal outdoor air rate in the winter is higher than in the summer, because cooling is more expensive than heating. The optimal outdoor air rate is higher than the free outdoor air rate during free-cooling and the optimal outdoor air rate is higher than the minimum or acceptable outdoor air rate, except at the hot outdoor temperature. It is also possible to calculate better design temperatures, than the two and three design temperatures given in ASHRAE Handbook, if the derived equations are solved.