Annual Heating Cost Research Articles

Assessment of the validity of using a radiant panel in the low-height floor heating

This paper examines the viability of using a radiant panel in lightweight low-height floor heating. In this structure, a dry screed with high thermal resistance is replaced by a low-resistance adhesive layer with reinforcement mesh. The absence of the radiant panel results in a reduction in heat output of 5%–17% for floor finishes with a thermal resistance of 0.001 m2K/W, 50%–54% for 0.05 m2K/W and 60%–62% for 0.1 m2K/W. A structure with a panel is characterised by a lower surface temperature amplitude (maximum 2.4 K) compared to a structure without it (8.8 K), which improves the comfort of floor users. The annual heating cost in a building equipped with the analysed structures was determined. The absence of the panel resulted in a cost increase of 13%, 37% and 79% for floor finish resistances of 0.001, 0.05 and 0.1 m2K/W, respectively. The SPBT for the purchase of radiant panels is 40 years for a floor resistance of 0.001 m2K/W, demonstrating the unprofitability of this solution. For resistances of 0.05 and 0.1 m2K/W, SPBT was 14 and 6 years, respectively. The choice of floor heating system should take into account the required heat output, thermal comfort and economic aspects. Practical application This paper assesses the validity of using radiant panels in a low-height floor heating structure, where the dry screed layer is replaced by an adhesive layer with reinforcement mesh. This structure is gaining popularity due to its quick installation and low height but has the disadvantage of the high panel cost. The paper evaluates the effect of panels on heat output and identifies the conditions under which their use is economically justified. Recipients of results are designers and contractors of heating systems. The recommendations can be the basis for selecting the optimum design solution for a lightweight floor heating system.

Cost-Effective Heating Control Approaches by Demand Response and Peak Demand Limiting in an Educational Office Building with District Heating

This study examined three different approaches to reduce the heating cost while maintaining indoor thermal comfort at acceptable levels in an educational office building, including decentralized (DDRC) and centralized demand response control (CDRR) and limiting peak demand. The results showed that although all these approaches did not affect the indoor air temperature significantly, the DDRC method could adjust the heating set point to between 20–24.5 °C. The DDRC approach reached heating cost savings of up to 5% while controlling space heating temperature without sacrificing the thermal comfort. The CDRC of space heating had limited potential in heating cost savings (1.5%), while the indoor air temperature was in the acceptable range. Both the DDRC and CDRC alternatives can keep the thermal comfort at good levels during the occupied time. Depending on the district heating provider, applying peak demand limiting of 35% can not only achieve 13.6% maximum total annual district heating cost saving but also maintain the thermal comfort level, while applying that of 43% can further save 16.9% of the cost, but with sacrificing a little thermal comfort. This study shows that demand response on heating energy only benefited from the decentralized control alternative, and the district heating-based peak demand limiting has significant potential for saving heating costs.

Social, Economic, and Environmental Effects of Electricity and Heat Generation in Yenisei Siberia: Is there an Alternative to Coal?

The energy sector is one of the most important pollutants in the atmosphere and causes significant emissions of greenhouse gases. In Russia, coal is the main contributor to the fossil fuel consumption of thermal power plants and boilers, thus affecting atmospheric air pollution by releasing particulate matter and nitrogen oxides, which are strongly associated with a negative impact on human health. This problem is especially acute for the resource regions of Yenisei, Siberia, a 2.5+ mln sq km macro-region in the very heart of Russia. In this paper, we analyze the impact of the structure of electricity and heat generation on emissions of pollutants and climate-active gases in Yenisei, Siberia, and give an overview of their social, ecological, and economic effects. More than 75% of electricity in Yenisei, Siberia, is produced by hydroelectric power plants that do not pollute the atmosphere. The rest of the electricity is generated in the cogeneration mode by thermal power plants, which are cores of the heat supply designs of cities. The share of individual coal-powered heat sources is still high. A detailed analysis of existing equipment and technologies at existing thermal power plants is needed to select options for their modernization to reduce emissions while keeping coal in use. Our calculations for the biggest cities of Krasnoyarsk Krai show that investments in the transition to heating with pellets will require RUB 184.7 million for Nazarovo and RUB 313.9 million for Kansk. At the same time, switching to electric heating is more than twice as expensive: RUB 498.6 million for Nazarovo and RUB 847.5 million for Kansk. The additional costs will range from RUB 21 to RUB 45.4 thousand per household per year for the pellet variant and from RUB 56.8 to RUB 122.5 thousand per year for electric heating, which could triple the annual heating costs. Thus, these options are unlikely to be implemented without direct state support. We argue that creating an attractive living environment in Yenisei, Siberia, must begin with intensive public investment in mitigating the environmental externalities caused by coal emissions.

Evaluation of energy-saving retrofit projects of existing rural residential envelope structures from the perspective of rural residents: the Chinese case.

The existing residential envelope in rural areas has low energy efficiency, with low energy utilization and serious energy waste for winter heating. However, in recent years, farmers have not undertaken energy efficiency retrofit projects for existing buildings in rural areas. This study proposed an evaluation model based on the logistic-AHP-TOPSIS method from the perspective of farmers. First, this study conducted a questionnaire survey of 208 rural households and used logistic models to determine which existing evaluation indicators significantly impact farmers' willingness to participate in energy efficiency retrofit projects. Second, the weights of the eight indicators were determined using AHP. Finally, this study evaluated the retrofit program of a case in Gansu Province using the TOPSIS method. In the analysis, total investment, annual winter heating costs and energy efficiency improvements were found to be the most important factors for farmers. The highest score for existing buildings was 0.3747 because there is no additional investment required; the option of partial retrofitting according to the actual needs of households scored 0.3350 because it balances economic performance with energy efficiency performance; The entire retrofit program has the highest investment and a long payback period, and its score is the lowest with 0.2904. Furthermore, the study recommended that a self-build and self-repair organization led by village collectives be developed to unify the retrofit design and construction and lower renovation costs. Bulk purchases could enable farmers to increase their power in negotiations.

Optimize heat prosumers' economic performance under current heating price models by using water tank thermal energy storage

Due to heat prosumers' dual roles of heat producer and heat consumer, the future district heating (DH) systems will become more flexible and competitive. However, the current heating price models have not yet supported the reverse heat supply from prosumers to the central DH system, which means the prosumers would gain no economic benefit from supplying heat to the central DH system. These unidirectional heating price models will reduce interest in prosumers, and thus hinder the promotion of prosumers in DH systems. This study aimed to optimize prosumers' economic performance under the current heating price models by introducing water tank thermal energy storage (WTTES). A dynamic optimization problem was formulated to explore prosumers' economic potentials. The size parameter of WTTESs was swept in prosumers to obtain the optimal storage size considering the trade-off between the payback period and the heating cost saving. The proposed method was tested on a campus DH system in Norway. The results showed that the prosumer's annual heating cost was saved up to 9%, and the investment of WTTES could be recovered in less than ten years. This study could provide guidelines on improving prosumers' economic performance and promote the development of prosumers during the transformation period of DH systems.

Performance evaluation of a seasonal residential space heating system based on thermochemical energy storage

Abstract Performance of a novel configuration of residential seasonal space heating system based on open thermochemical energy storage (TCES) is numerically investigated. The system comprises two open TCES reactors and a humidifier operating in a complete closed-loop or in partial recirculation to maintain a comfortable temperature in a detached room. A detailed three-dimensional model for flow and heat transfer in a detached room is coupled with a model of the reactive bed undergoing exothermic reaction. The thermal and breathing comfort requirements in the room are obtained simultaneously by operating the system on partially recirculated air. A comparative study of the closed-loop configuration with its open-loop counterpart for the detached room indicates a significant energy saving of 76.61% (92.90 W) for the former. A realistic case study is conducted by operating the system with 10% fresh air, subject to ambient conditions for a winter night in Pune, India. Numerical studies conducted for constant ambient conditions reveal improvement in the room’s heat distribution with increased airflow rate. Employment of two TCES reactors instead of one reactor enhances the Coefficient of Performance (COP) by a factor of 1.39. Adiabatic humidification in the humidifier eliminates its external heat requirement with the increase in the blower power input. Investigation of different locations for the exhaust vent is carried out for minimum heat loss to the surroundings. The system’s energy consumption reduces by 10.18% using a cross-flow air-to-air heat exchanger for pre-heating fresh air. An annual heating cost of 0.44 USD.kWh−1 is estimated for the system.

New Low-Temperature Central Heating System Integrated with Industrial Exhausted Heat Using Distributed Electric Compression Heat Pumps for Higher Energy Efficiency

Industrial exhausted heat can be used as the heat source of central heating for higher energy efficiency. To recover more industrial exhausted heat, a new low-temperature central heating system integrated with industrial exhausted heat using distributed electric compression heat pumps is put forward and analyzed from the aspect of thermodynamics and economics. The roles played by the distributed electric compression heat pumps in improving both thermal performance and financial benefit of the central heating system integrated with industrial exhausted heat are greater than those by the centralized electric compression heat pumps. The proposed low-temperature central heating system has higher energy efficiency, better financial benefit, and longer economical distance of transmitting exhausted heat, and thus, its configuration is optimal. For the proposed low-temperature central heating system, the annual coefficient of performance, annual product exergy efficiency, heating cost, and payback period are about 22.2, 59.4%, 42.83 ¥/GJ, and 6.2 years, respectively, when the distance of transmitting exhausted heat and the price of exhausted heat are 15 km and 15 ¥/GJ, respectively. The economical distance of transmitting exhausted heat of the proposed low-temperature central heating system could approach 25.1 km.

Evaluation of different clean heat supply modes based on crop straws in the rural area of Northern China.

This study evaluated eight different types of heat supply modes based on crop residues utilization in the rural area of Northern China, including straw densified solid fuel combustion, pyrolysis char combustion, biogas combustion, and pyrolysis gas combustion for single household heating; straw densified solid fuel combustion, baling straw combustion, biogas combustion, and pyrolysis gas combustion for centralized heating; centralized gas supply and centralized pyrolysis gas supply modes. Comprehensively evaluation was the cost of these different eight heat supply modes. The results showed that the cost of straw densified solid fuel combustion, pyrolysis char combustion for single household heating were 2346 RMB/household and 2390 RMB/household. With the heating scale of 200-500 households, the pipe network distance was 8 m/household, and the total annual heating cost was predicted at 2201-2992 RMB/household. Among them, the cost of straw baling combustion for centralized heating was the lowest, the cost of densified solid fuel, biogas, and pyrolysis for centralized heating was the second, and the cost of biogas and pyrolysis gas for centralized gas supply was the highest. For the increase in every 1 m of the pipeline distance, the investment cost will increase by about 645 RMB for each household. This study provides a basis for the implementation of clean heat supply technologies in less-developed areas and guidance of village heat-supply subsidy policies. Keywords: crop straw, biomass, clean heating, rural area, villages and towns, model, cost DOI: 10.25165/j.ijabe.20201305.5600 Citation: Huo L L, Yao Z L, Jia J X, Zhao L X, Cong H B, Meng H B, et al. Evaluation of different clean heat supply modes based on crop straws in the rural area of Northern China. Int J Agric & Biol Eng, 2020; 13(5): 209–217.

Evaluation of different clean heat supply modes based on crop straws in the rural area of Northern China

This study evaluated eight different types of heat supply modes based on crop residues utilization in the rural area of Northern China, including straw densified solid fuel combustion, pyrolysis char combustion, biogas combustion, and pyrolysis gas combustion for single household heating; straw densified solid fuel combustion, baling straw combustion, biogas combustion, and pyrolysis gas combustion for centralized heating; centralized gas supply and centralized pyrolysis gas supply modes. Comprehensively evaluation was the cost of these different eight heat supply modes. The results showed that the cost of straw densified solid fuel combustion, pyrolysis char combustion for single household heating were 2346 RMB/household and 2390 RMB/household. With the heating scale of 200-500 households, the pipe network distance was 8 m/household, and the total annual heating cost was predicted at 2201-2992 RMB/household. Among them, the cost of straw baling combustion for centralized heating was the lowest, the cost of densified solid fuel, biogas, and pyrolysis for centralized heating was the second, and the cost of biogas and pyrolysis gas for centralized gas supply was the highest. For the increase in every 1 m of the pipeline distance, the investment cost will increase by about 645 RMB for each household. This study provides a basis for the implementation of clean heat supply technologies in less-developed areas and guidance of village heat-supply subsidy policies. Keywords: crop straw, biomass, clean heating, rural area, villages and towns, model, cost DOI: 10.25165/j.ijabe.20201305.5600 Citation: Huo L L, Yao Z L, Jia J X, Zhao L X, Cong H B, Meng H B, et al. Evaluation of different clean heat supply modes based on crop straws in the rural area of Northern China. Int J Agric & Biol Eng, 2020; 13(5): 209–217.

Geo-Solar District Heating – Lessons Learnt from a not Realised Project

For the new housing area with approx. 130 low energy residential houses, located in Kassel, Germany, various supply concepts are investigated. Main objective of the project is the development of an innovative and optimised heat supply concept based on renewable energies and a low temperature district heating for later realisation.During the course of the project several heat supply concepts have been investigated and compared to give an input to the decision and realisation process. A promising heat supply concept is based on a central ground source heat pump in combination with a low temperature district heating (40°C supply temperature) for space heating and decentralised solar thermal systems for domestic hot water preparation. The advantages of this supply variant are comparable low annual heating costs and about 60% lower CO2-emissions in comparison to the reference system (decentralized air / water heat pump with solar thermal system).Due to time constrains it was decided not to realise the above mentioned energy concept. However, the research project took up the task to investigate the transferability of the concept in technological and economical perspectives to other locations and boundary conditions. From the results of the study the importance of a very high connection rate can be highlighted. Also the question of the particular business models for such capital demanding projects (high investment costs for the heating grid vs. low energy demand/sales) has been regarded.

Development of an Innovative Low Temperature Heat Supply Concept for a New Housing Area

The domestic energy demand of buildings is responsible for one third of the world's final energy consumption. To increase the sustainability of new housing areas, the identification of innovative heat supply concepts based on renewable energy sources (RES) is required. For the new housing area “Zum Feldlager”(Kassel, Germany), various supply concepts are studied. Main objective is the development of an innovative and efficient supply concept based on RES and low temperature district heating (LTDH) for practical implementation. In the course of different studies, centralised and decentralised supply strategies are analysed. The most promising supply concept is based on a central ground source heat pump in combination with LTDH and decentralised solar thermal systems. In comparison to a reference concept the annual heating costs and the CO2-emissions are lower. This project is a cooperative activity and of the Fraunhofer IBP, Institute for decentralized Energy Technologies (IdE), Kassel University, City of Kassel and Staedtische Werke Kassel AG. The paper covers a topic from IEA DHC Annex TS1.

Optimized design and operation of heat-pipe photovoltaic thermal system with phase change material for thermal storage

This work aims to optimize the design and operation of a heat pipe photovoltaic-thermal (HP-PV/T) panel integrated with a phase change material (PCM) thermal storage water tank to produce electricity and hot water for an office building. A transient mathematical model for the integrated HP-PV/T-PCM system was used to predict its performance for known environmental and solar conditions and PCM melting point. The validated model was applied on a typical office space in the city of Beirut to obtain an optimal design using a derivative free genetic algorithm. The incremental system cost associated with a heat pipe and PCM tank was used in the optimization to obtain a design resulting in minimum annual auxiliary heating cost to meet the hot water demand while providing the electricity needs at a lower number of PV panels due to improved efficiency. An optimal system of 4 kW (20 PV panels each at 1.6 m2) was found to meet the electric power needs all year round. The optimal PCM storage tank size per panel was 37 l at PCM total mass of 22.42 kg with melting temperature of 33 °C.

투자회수기간을 고려한 군 주거시설의 단열수준 산정 연구

Purpose: This study, which is based on the investment payback periods, aims to suggest the proper insulation level which can be adapted to the Defense Military Facility Criteria regarding the military residential condominiums. For the energy performance simulation, it is required to collect the residential data regarding the military condominiums and climatic data concerning the regions they belongs to. The estimates through energy performance simulation are the regional heating loads and the heating transmission coefficients of building components. Method: With the heating loads, the annual heating cost saving per square meters is assessed. With the heating transmission coefficients of building components, the additional insulation installment cost per square meters is evaluated. With two outcomes, one as an annual value and the other as a present value, the investment payback period is calculated. Result: In result, it could be concluded that 55~70% insulation ratio can lead a superior residental environments as well as be contributed to the national policy associated with zero-energy buildings because the estimated investment payback period is shorter than the life span of the military residental condominiums. This upshot can be used as a foundation to enactment the Defense Military Facility Criteria associated with military residential condominiums.

Integration of space heating and hot water supply in low temperature district heating

District heating may supply many consumers efficiently, but the heat loss from the pipes to the ground is a challenge. The heat loss may be lowered by decreasing the network temperatures for which reason low temperature networks are proposed for future district heating. The heating demand of the consumers involves both domestic hot water and space heating. Space heating may be provided at low temperature in low energy buildings. Domestic hot water, however, needs sufficient temperatures to avoid growth of legionella. If the network temperature is below the demand temperature, supplementary heating is required by the consumer. We study conventional district heating at different temperatures and compare the energy and exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature district heating. This includes direct electric heating and three heat pump solutions applying R134a and R744. The results show that conventional solutions at lowest possible temperature have the highest exergetic efficiency of 28% and lowest annual cost of € 690 for a 159m2 house. The best low temperature system is an R134a heat pump with hot water storage on the district heating side, which reaches 25% exergetic efficiency.

Comparison of Greenhouse Dehumidification Strategies

<abstract> <bold><sc>Abstract. </sc></bold>Two dehumidification methods, including air-to-air heat exchangers and mechanical refrigeration dehumidifiers, were compared with dehumidification using a conventional exhaust ventilation system. The comparisons included capital cost, operating cost, durability, ease of installation and maintenance, and effectiveness for different seasons of the year. The heat exchangers were more effective for moisture control during cold and mild seasons than during humid and warm periods, while the dehumidifiers were effective in controlling the indoor moisture year-round due to their independence from outside air conditions. While the dehumidifiers consumed the highest amount of electrical energy thus resulting in the highest cost, they consumed the lowest amount of total energy, defined as the sum of the electrical energy consumption and the resultant heat loss from the greenhouse due to dehumidification. Although the heat exchanger method consumed approximately 81% of the total energy consumed by the exhaust fan dehumidification system due to the sensible heat recovered from the exhaust air, the total costs of the two methods were similar due to the lower electrical energy consumption by the latter. Considering a 10-year payback period, dehumidification by the exhaust fan system was the most cost-effective method with the lowest capital and maintenance cost. However, it is only effective during cold and mild seasons, and not during warm weather conditions. Mechanical refrigeration is recommended for summer dehumidification, and both methods could be used during different seasons to achieve good moisture control year-round. After the application of dehumidification, the crop loss rate was reduced by 1.6% to 2.5%, which led to an annual revenue increase of $3,000 per year. Although the average dehumidification cost was approximately 10% of the annual heating cost of the greenhouse, when considering the reduced crop loss and yield increase, dehumidification is strongly recommended.

Energy Saving Benefit Evaluation of Zone and Time Control Heating for One College

In consideration of the current situation that college buildings are still heated as normal without occupancy,causing energy waste,the on-duty heating will be adopted in college buildings without occupancy under the premise to ensure the indoor comfort requirements.In the case of one college, the energy saving rate and cost saving rate were evaluated for college buildings that used zone and time control heating systems for buildings of different functions.The results show that the annual heating energy saving rate is 34.5%,and the annual heating cost saving rate is 51.5%. In similar collage buildings, 5.48kg of standard coal and 14.43Yuan per square meter of structure area can be saved per year if using zone and time control heating.

블라인드 내장형 창호시스템의 에너지 성능 및 경제성 평가에 관한 연구

본 연구에서는 전열해석 프로그램인 피지벨(PHYSIBEL)을 사용하여 블라인드 내장형 창호시스템의 일사차단성능 및 단열성능에 따른 에너지 성능을 평가하였다. 피지벨 해석시 창호별 구성 재료의 열적특성과 해석조건을 결정하기 위해서 Mock-up시험을 실시하였으며, 컴퓨터 시뮬레이션을 통한 결과를 바탕으로 공동주택 기준층 1개 세대(33평형)를 대상으로 연간에너지 소비특성, 연간전열량, 연간 냉난방 비용을 분석하였다. 실험결과, 연간전열량은 일반 창호시스템 대비 블라인드 내장형 창호시스템에서 블라인드를 올린 경우 냉방시 10%, 난방시 11% 절감할 수 있으며, 블라인드를 내린 경우 냉방시 25%, 난방시 30%정도를 절감할 수 있는 것으로 나타났다. 블라인드 내장형 창호시스템의 냉 난방 부하 절감량은 일반 창호시스템에 비해 냉방시 283.3KWh, 난방시 76.3KWh 로 냉 난방 에너지 절감효과는 단위세대당 359.6KWh 절감시킬 수 있는 것으로 나타났으며, 이것은 단위세대당 연간 에너지원단위(TOE) 약 0.078toe, 이산화탄소톤(<TEX>$tCO_2$</TEX>) <TEX>$0.16tCO_2$</TEX>을 절감시킬 수 있어 온실가스 저감에도 유리할 것으로 판단된다. 또한, 블라인드 내장형 창호시스템의 냉 난방비용 절감액은 일반창호시스템과 비교하여 연간 냉방비용 10만원, 난방비용 5만원으로 연간 냉 난방 비용을 약 15만원 정도 절감시킬 수 있는 것으로 나타났다. This study evaluated the energy efficiency of a windows system using built-in blinds, with regard to their insulation performance and their blocking of solar radiation. The study took advantage of the "Physibel Voltra" program as a physical simulation of heat transfer. To simulate the "Physibel Voltra" program, I practiced a mock-up test to determine heating quality and translation condition. I analyzed the propensity to annual energy consumption, the annual quantity of heat transfer, and the annual cooling and heating cost through a computer simulation for one general household in an apartment building. In the test, it was found that compared to a general windows system, a windows system with built-in blinds reduced the annual heat transfer by 10% in cooling states and by 11% in heating states when the blind was up. When the blind was down, the windows system with built-in blinds reduced the annual heat transfer by 25% in cooling states and 30% in heating states. When a windows system with built-in blinds is compared with a general windows system, the quantity of cooling and heating loads is reduced by 283.3kw in cooling states and 76.3kw in heating states. This leads to a reduction in the required cooling and heating energy of 359.6kw per house. It is thus judged that the use of a windows system with built-in blinds is advantageous in terms of reducing greenhouse gas emissions, because the annual TOE (tons of oil equivalent) per house is reduced by 0.078TOE, while <TEX>$tCO_2$</TEX> is reduced by <TEX>$0.16tCO_2$</TEX>. In addition, compared with a general windows system, the cost of cooling and heating loads in the system reduces the annual cooling cost by 100,000won, and the annual heating cost by 50,000won. Ultimately, this means that cooling and heating loads are cut by 150,000won per year.

Rural houses heating costs

Average full (including capital, operation and maintenance costs) annual heating costs in a standard family house with 180 m2 of floor surface are compared for various heating systems under the Polish economic conditions. The compared heating technologies comprise water to water and ground loop heat pumps with both vertical and horizontal loops, a liquid gas combustion furnace, an earth gas combustion furnace, a coal combustion furnace, a straw combustion furnace, a wood combustion furnace and an electric stove. A sensitivity analysis with regard to the interest rate and the value of owner’s work did not change the general conclusion that in most cases heat pumps were the cheapest, while oil and coal burning furnaces or an electric boiler the most expensive solutions. The cost of own labour was decisive for the appraisal of labour intensive systems

THE COMPARISION OF SOMA LIGNITE COAL AN FUEL-OIL WITH GEOTHERMAL ENERGY FOR HEATING BUILDINGS

In this study, a house that has four storeys and one hundred square meters flat was taken sample. Because this house can be heated with three different alternatives Soma lignite coal, fuel oil and geothermal, necessary first investment and annual heating costs were investigated. In addition, at heating building of geothermal energy whether became economic was researched. Economic analysis of used fuels at heating to a flat that is one hundred square meters been done. According to result of this economic analysis, heating with geothermal energy is more economic than heating with other energy sources.

Measurements of Air Leakage through Revolving Doors of Institutional Building

Exterior doors and entrances of nonresidential buildings are major sources of energy losses caused by air infiltration or exfiltration due to the frequent use of doors and the pressure difference across each door, created by the wind, stack effect, or ventilation systems. Information regarding the air leakage characteristics of manually or power-operated revolving doors is available in the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) publications, based on studies carried out in the 1950s and 1960s. This paper presents results from a recent study carried out to investigate the air leakage characteristics of four revolving doors of a large institutional building in Montreal. These results are compared with data available in ASHRAE publications, as well as with the specifications of the Model National Energy Code of Canada for Buildings and ASHRAE Standard 90.1. The impact of the quality of seals on the annual heating costs is also evaluated.