Total heat exchanging element paper

Abstract

The object of the present invention is to provide an excellent total heat exchanging element paper and a total heat exchanging element which are excellent in heat transferability, water vapor permeability and gas barrier properties and cause no mixing of supplied air and discharged air. The present invention provides a total heat exchanging element paper using a paper made using mainly a natural pulp beaten to a Canadian modification freeness of not more than 150 ml, a substantially non-porous total heat exchanging element paper comprising a substantially non-porous cellulosic base which contains a moisture absorbing agent, a non-porous total heat exchanging element paper having a high gas barrier property which has a thickness of not more than 100 m and a carbon dioxide permeation constant specified in JIS K7126 of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa, and a non-porous total heat exchanging element paper having a high enthalpy exchangeability which has a water vapor permeability specified in JIS Z0208 of not less than 1000 g/m.sup.2.Math.24 Hr at 20 C. and 65% RH.

Claims

1. A total heat exchanging element paper which comprises a paper containing, as a fiber component, only a natural pulp beaten to a Canadian modification freeness of not more than 150 ml, wherein the Canadian modification freeness is the value obtained by carrying out a measurement in accordance with Canadian standard freeness testing method of JIS P8121, except that 0.5 g of a pulp in absolute dry weight is used and a plain weave bronze wire of 80 mesh is used as a sieve; wherein the total heat exchanging element paper is treated by coating or impregnating with a moisture absorbing agent selected from the group consisting of lithium chloride and diammonium phosphate; and wherein the total heat exchanging element paper has a density of not less than 0.9 g/cm.sup.3; and wherein the total heat exchanging element paper has a carbon dioxide permeability measured in accordance with JIS K7126, method A (differential pressure method) of not more than 3.410.sup.9 mol/m.sup.2.Math.s.Math.Pa, wherein the total heat exchanging element paper has a water vapor permeability at 40 C., 90% of 6100 g/m.sup.2.Math.24 h or more, measured in accordance with JIS Z 0208, except that the water vapor permeability was obtained by measuring the weight every 1 hour.

2. A total heat exchanging element, which is a partition plate comprising a corrugated paper, said corrugated paper comprising the total heat exchanging element paper of claim 1.

3. A heat exchange method, comprising the step of: passing air discharged from a room along one side of the total heat exchanging element paper of claim 1, and passing supplied air along the other side of the total heat exchanging element paper.

4. The total heat exchanging element paper according to claim 1 wherein the total heat exchanging element paper has been subjected to a calendering treatment so as to have a density of not less than 0.9 g/cm.sup.3.

Description

EXAMPLE 1

(1) Soft wood bleached kraft pulp (NBKP) was macerated at a concentration of 3% and then beaten by a double disc refiner and a deluxe finer until the Canadian modification freeness of the pulp reached 100 ml. Thereafter, a total heat exchanging element paper having a basis weight of 40 g/m.sup.2 was produced by a Fourdrinier paper machine. By a size press, 1 g/m.sup.2 of lithium chloride was coated, followed by subjecting to machine calendering treatment so as to give a density of 0.9 g/cm.sup.3.

EXAMPLE 2

(2) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that the Canadian modification freeness of the pulp was changed to 150 ml.

EXAMPLE 3

(3) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that the Canadian modification freeness of the pulp was changed to 50 ml.

EXAMPLE 4

(4) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that diammonium phosphate was used in place of lithium chloride.

EXAMPLE 5

(5) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that starch in an amount of 0.1 g/m.sup.2 was used in place of lithium chloride.

EXAMPLE 6

(6) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that the machine calendering treatment was carried out to give a density of 0.8 g/cm.sup.3.

EXAMPLE 7

(7) A total heat exchanging element paper was obtained in the same manner as in Example 1, except that the Canadian modification freeness of the pulp was changed to 200 ml.

(8) The total heat exchanging element papers obtained in the above Examples were evaluated by the following evaluation methods. The results are shown in Table 1.

(9) (Canadian Modification Freeness)

(10) The Canadian modification freeness of the pulp was measured in accordance with Canadian standard freeness testing method of JIS P8121, except that 0.5 g of a pulp in absolute dry weight was used and a bronze wire of 80 mesh was used as a sieve plate.

(11) (Water Vapor Permeability)

(12) Sensible heat (humidity) exchangeability of the total heat exchanging element paper was evaluated in terms of water vapor permeability. The water vapor permeability at 40 C., 90% of the total heat exchanging element paper was measured in accordance with JIS Z0208, except that the water vapor permeability was obtained by measuring the weight every 1 hour since the water vapor permeability was great.

(13) (Quantity of Heat Transfer)

(14) Latent heat (temperature) exchangeability of the total heat exchanging element paper was evaluated in terms of quantity of heat transfer, which was measured by QTM method (probe method which was an improved hot-wire method).

(15) (Carbon Dioxide Permeability)

(16) Gas barrier property of the total heat exchanging element paper was evaluated in terms of carbon dioxide permeability, which was measured in accordance with method A (differential pressure method) of JIS K7126. In Table 1, the expression 10.sup.7 or more and unmeasurable means that when the permeability was 10.sup.7 mol/m.sup.2.Math.s.Math.Pa or more, the permeation was too rapid and the permeability could not be measured.

(17) TABLE-US-00001 TABLE 1 Canadian Quantity modification Water vapor of heat Carbon dioxide freeness Density permeability transfer permeability ml g/cm.sup.3 g/m.sup.2 .Math. 24 h W/ C. mol/m.sup.2 .Math. s .Math. Pa Example 1 100 0.9 6200 12800 1.0 10.sup.10 Example 2 150 0.9 6300 12200 3.4 10.sup.9 Example 3 50 0.9 6200 13200 2.8 10.sup.10 Example 4 100 0.9 6100 12900 1.1 10.sup.10 Example 5 100 0.9 5000 12800 1.2 10.sup.10 Example 6 100 0.8 5900 12000 1.0 10.sup.9 Example 7 200 0.9 6300 11500 Not less than 10.sup.7 and unmeasurable
(Evaluation)

(18) It is clear from the results of Examples 1-7 that the total heat exchanging element papers of the present invention are excellent in heat transferability, water vapor permeability and gas barrier property. On the other hand, it is clear that when the Canadian modification freeness of pulp is greater than 150 ml, the carbon dioxide permeability is great and the paper is much inferior in gas barrier property to the papers of the present invention. It is further clear that when a moisture absorbing agent is contained, the water vapor permeability synergistically increases without damaging other performances, and papers higher in heat exchangeability can be obtained. Furthermore, it can be seen that when the density is not less than 0.9 g/cm.sup.3, the carbon dioxide permeability decreases and this is preferred from the viewpoint of gas barrier property.

(19) (1) The second aspect:

EXAMPLE 8

(20) Soft wood bleached kraft pulp (NBKP) was macerated at a concentration of 2.8% and then sufficiently beaten by a double disc refiner and a deluxe finer. Thereafter, a base paper having a basis weight of 40 g/m.sup.2 was produced by a Fourdrinier paper machine. At the production step, 5 g/m.sup.2 of a diammonium phosphate solution was coated as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 1. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 45 m.

EXAMPLE 9

(21) A base paper having a basis weight of 40 g/m.sup.2 was produced by a Fourdrinier paper machine in the same manner as in Example 8, except that the beating was more sufficiently carried out. At the production step, 5 g/m.sup.2 of a diammonium phosphate solution was coated as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 2. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.14 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 45 m.

EXAMPLE 10

(22) A base paper was produced in the same manner as in Example 9, except that the basis weight was 20 g/m.sup.2. At the production step, 3 g/m.sup.2 of a diammonium phosphate solution was coated as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 3. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.14 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126.

EXAMPLE 11

(23) A base paper was produced in the same manner as in Example 9, except that the basis weight was 20 g/m.sup.2. At the production step, 4 g/m.sup.2 in total of a diammonium phosphate solution and lithium chloride were coated as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 4. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.14 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 25 m.

EXAMPLE 12

(24) A base paper was produced in the same manner as in Example 9, except that the basis weight was 100 g/m.sup.2. At the production step, 10 g/m.sup.2 in total of a diammonium phosphate solution and lithium chloride were coated as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 5. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.14 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 110 m.

EXAMPLE 13

(25) A base paper was produced in the same manner as in Example 12, except that the basis weight was 150 g/m.sup.2. At the production step, 15 g/m.sup.2 in total of a diammonium phosphate solution and lithium chloride were coated as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 6. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 5.010.sup.14 mol.Math.m/m.sup.2.Math.s Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 165 m.

EXAMPLE 14

(26) Total heat exchanging elements of corrugate type were produced using the total heat exchanging element papers produced in Examples 8-13 as partition plates and woodfree papers of 75 g/m.sup.2 as flute portions. There were no problems in production and the elements functioned satisfactorily.

EXAMPLE 15

(27) Soft wood bleached kraft pulp (NBKP) was macerated at a concentration of 3% and then moderately beaten by a double disc refiner. Thereafter, a base paper having a basis weight of 40 g/m.sup.2 was produced by a Fourdrinier paper machine. At the production step, 5 g/m.sup.2 of a diammonium phosphate solution was coated as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 7. This total heat exchanging element paper was substantially porous, and had a carbon dioxide permeation constant of 1.010.sup.9 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 45 m.

EXAMPLE 16

(28) A base paper was produced in the same manner as in Example 15, except that the basis weight was 20 g/m.sup.2. At the production step, 3 g/m.sup.2 of a diammonium phosphate solution was coated as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 8. This total heat exchanging element paper was substantially porous, and had a carbon dioxide permeation constant of 1.010.sup.9 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 25 m.

EXAMPLE 17

(29) A base paper was produced in the same manner as in Example 15, except that the basis weight was 100 g/m.sup.2. At the production step, 10 g/m.sup.2 in total of a diammonium phosphate solution and lithium chloride were coated as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 9. This total heat exchanging element paper was substantially porous, and had a carbon dioxide permeation constant of 1.010.sup.9 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 115 m.

EXAMPLE 18

(30) A base paper was produced in the same manner as in Example 15, except that the basis weight was 100 g/m.sup.2. At the production step, first, PVA was coated in an amount of 3 g/m.sup.2 and dried, and then 10 g/m.sup.2 in total of a diammonium phosphate solution and lithium chloride were coated as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 10. This total heat exchanging element paper was substantially non-porous, and had a carbon dioxide permeation constant of 1.010.sup.10 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126 and a thickness of 115 m.

(31) The total heat exchanging element papers produced in the above Examples were evaluated by the following evaluation methods. The results are shown in Table 2.

(32) (Water Vapor Permeability)

(33) Evaluation was conducted in the same manner as in Examples 1-7. This water vapor permeability is a value indicating humidity exchangeability, and the larger value means the better exchangeability.

(34) (Quantity of Heat Transfer)

(35) Evaluation was conducted in the same manner as in Examples 1-7. This quantity of heat transfer is an indication representing heat exchangeability, and the larger value means the better exchangeability.

(36) (Gas Barrier Property: Leakage Amount of Carbon Dioxide)

(37) In the same manner as in Example 14, total heat exchanging elements of corrugate type were produced using the total heat exchanging element papers produced in Examples 8-13 and 15-18 as partition plates and woodfree papers of 75 g/m.sup.2 as flute portions. A synthetic air gas containing nitrogen and oxygen at 79:21 was allowed to pass from the air supplying side of the total heat exchanging elements and a foul gas containing carbon dioxide at a given concentration was allowed to pass from the air discharging side to perform ventilation. Concentration of carbon dioxide at the exit of the air supplying side was measured and this concentration was compared with the concentration of carbon dioxide at the inlet of the air discharging side, and the amount of carbon dioxide which leaked was calculated and shown by %. When the amount of the leaking carbon dioxide was 5% or more, this was indicated by x; when it was 1% or more and less than 5%, this was indicated by ; when it was 0.1% or more and less than 1%, this was indicated by o; and when it was less than 0.1%, this was indicated by .

(38) TABLE-US-00002 TABLE 2 Water Quantity Leakage vapor of heat amount of permeability transfer carbon g/m.sup.2 .Math. 24 h W/ C. dioxide Example 8 6300 13000 Example 9 6300 13500 Example 10 7500 25000 Example 11 8500 26000 Example 12 5000 5500 Example 13 4500 3000 Example 15 6200 12500 X Example 16 6200 20000 X Example 17 5000 5000 X Example 18 5000 5000
(Evaluation)

(39) It is clear from the results of Examples 8-13 and 15-18 that the total heat exchanging elements using the non-porous total heat exchanging element papers of the present invention are excellent in heat transferability, water vapor permeability and gas barrier property. It is clear that in the case of using porous type papers, when the thickness is increased or a binder is mixed to fill the pores, the amount of leaking carbon dioxide can be reduced, but simultaneously the water vapor permeability and the quantity of heat transfer decrease, and thus satisfactory total heat exchanging element papers cannot be obtained, and, besides, the leakage of carbon dioxide in the case of using the porous type papers is extremely greater than that in the case of using the non-porous total heat exchanging element papers of the present invention and the gas barrier property of the porous type papers is considerably inferior to the papers of the present invention. Since the total heat exchanging element papers of the present invention are basically non-porous, even when the thickness is reduced, they have sufficient carbon dioxide barrier property, and by reducing the thickness, both water vapor permeability and quantity of heat transfer (heat exchangeability) are improved, resulting in satisfactory total heat exchanging element papers. The total heat exchanging elements using the total heat exchanging element papers of the present invention satisfactorily perform exchanging of heat and water without causing mixing of supplied air and discharged air from outside and inside of a room, and thus can provide high total heat exchanging function.

(40) (3) The third aspect:

EXAMPLE 19

(41) A condenser paper having a basis weight of 20 g/m.sup.2 was coated with 10 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a condenser paper type total heat exchanging element paper 11. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 20 m.

EXAMPLE 20

(42) In the same manner as in Example 19, a condenser paper having a basis weight of 50 g/m.sup.2 was coated with 30 g/m.sup.2 of a diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a condenser paper type total heat exchanging element paper 12. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous, and had a thickness of 50 m.

EXAMPLE 21

(43) In the same manner as in Example 19, a condenser paper having a basis weight of 8 g/m.sup.2 was coated with 4 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a condenser paper type total heat exchanging element paper 13. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous, and had a thickness of 8 m.

EXAMPLE 22

(44) A typewriter paper having a basis weight of 16 g m.sup.2 and a density of 0.65 g/cm.sup.3 was coated with 10 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 14. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 20 m.

EXAMPLE 23

(45) In the same manner as in Example 22, a typewriter paper having a basis weight of 40 g/m.sup.2 was coated with 30 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 15. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 50 m.

EXAMPLE 24

(46) In the same manner as in Example 22, an ultra-thin typewriter paper having a basis weight of 8 g/m.sup.2 was coated with 4 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 16. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous, and had a thickness of 10 m.

EXAMPLE 25

(47) A condenser paper having a basis weight of 75 g/m.sup.2 was coated with 50 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a condenser paper type total heat exchanging element paper 17. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 75 m.

EXAMPLE 26

(48) A condenser paper having a basis weight of 5 g/m.sup.2 was coated with 2.6 g/m.sup.2 of a 50 wt % diammonium phosphate solution and a lithium chloride solution as moisture absorbing agents, followed by drying to obtain a condenser paper type total heat exchanging element paper 18. This condenser paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous, and had a thickness of 5 m.

(49) The total heat exchanging element papers produced in the above Examples were evaluated by the following evaluation methods. The results are shown in Table 3.

(50) (Water Vapor Permeability)

(51) Evaluation was conducted in the same manner as in Examples 1-7.

(52) (Quantity of Heat Transfer)

(53) Evaluation was conducted in the same manner as in Examples 1-7.

(54) (Gas Barrier Property: Leakage Amount of Carbon Dioxide)

(55) Evaluation was conducted in the same manner as in Examples 8-13 and 15-18.

(56) TABLE-US-00003 TABLE 3 Quantity Leakage Condenser Thick- Water vapor of heat amount of paper or ness permeability transfer carbon other paper m g/m.sup.2 .Math. 24 h W/ C. dioxide Example Condenser 20 7800 28000 19 paper Example Condenser 50 6000 12000 20 paper Example Condenser 8 15500 42000 21 paper Example Typewriter 20 6200 22500 X 22 paper Example Typewriter 50 5000 10000 X 23 paper Example Typewriter 10 10500 38000 X 24 paper Example Condenser 75 2000 6000 25 paper Example Condenser 5 16000 44000 X 26 paper
(Evaluation)

(57) It is clear from the results of Examples 19-21 and 22-26 that the total heat exchanging elements using the condenser type non-porous total heat exchanging element papers of the present invention are excellent in heat transferability, water vapor permeability and gas barrier property. It is clear that in the case of using porous type papers without using the condenser papers, when the thickness is increased or a binder is mixed to fill the pores, the amount of leaking carbon dioxide can be reduced, but simultaneously the water vapor permeability and the quantity of heat transfer decrease, and thus satisfactory total heat exchanging element papers cannot be obtained, and, besides, the leakage amount of carbon dioxide in the case of using the porous type papers is extremely greater than that in the case of using the non-porous total heat exchanging element papers of the present invention and the gas barrier property of the porous type papers is considerably inferior to the papers of the present invention. Since the condenser paper type total heat exchanging element papers of the present invention are basically non-porous, even when the thickness is reduced, they have sufficient carbon dioxide barrier property, and by reducing the thickness, both water vapor permeability and heat transfer (heat exchangeability) are improved, resulting in satisfactory total heat exchanging element papers. The total heat exchanging elements using the total heat exchanging element papers of the present invention satisfactorily perform exchanging of heat and water without causing mixing of air supplied from outside of a room and air discharged from inside of a room, and thus can provide high total heat exchanging function. Furthermore, the papers having a thickness within the range of the present invention can give good heat transferability, water vapor permeability and gas barrier property. If the thickness is more than that of the present invention, the gas barrier property is sufficient, but the heat transferability and the water vapor permeability are not sufficient, and thus the papers are not preferred as total heat exchanging element papers. If the thickness is less than that of the present invention, the gas barrier property is not sufficient probably because of formation of pin holes, and thus the papers are also not preferred as total heat exchanging element papers.

EXAMPLE 27

(58) A tracing paper having a basis weight of 20 g/m.sup.2 was coated with 12 g m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a tracing paper type total heat exchanging element paper 19. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 20 m.

EXAMPLE 28

(59) In the same manner as in Example 27, a tracing paper having a basis weight of 50 g/m.sup.2 was coated with 33 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a tracing paper type total heat exchanging element paper 20. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 50 m.

EXAMPLE 29

(60) In the same manner as in Example 27, a tracing paper having a basis weight of 8 g/m.sup.2 was coated with 5 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a tracing paper type total heat exchanging element paper 21. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 8 m.

EXAMPLE 30

(61) A typewriter paper having a basis weight of 16 g/m.sup.2 was coated with 12 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 22. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 20 m.

EXAMPLE 31

(62) In the same manner as in Example 30, a typewriter paper having a basis weight of 40 g/m.sup.2 was coated with 33 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 23. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 50 m.

EXAMPLE 32

(63) In the same manner as in Example 30, an ultra-thin typewriter paper having a basis weight of 8 g/m.sup.2 was coated with 5 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 24. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 10 m.

EXAMPLE 33

(64) A tracing paper having a basis weight of 75 g/m.sup.2 was coated with 55 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a tracing paper type total heat exchanging element paper 25. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 75 m.

EXAMPLE 34

(65) A tracing paper having a basis weight of 5 g/m.sup.2 was coated with 2.8 g/m.sup.2 of a 50 wt % diammonium phosphate solution and a lithium chloride solution as moisture absorbing agents, followed by drying to obtain a tracing paper type total heat exchanging element paper 26. This tracing paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 5 m.

(66) The total heat exchanging element papers produced in the above Examples were evaluated by the following evaluation methods. The results are shown in Table 4.

(67) (Water Vapor Permeability)

(68) Evaluation was conducted in the same manner as in Examples 1-7.

(69) (Quantity of Heat Transfer)

(70) Evaluation was conducted in the same manner as in Examples 1-7.

(71) (Gas Barrier Property: Leakage Amount of Carbon Dioxide)

(72) Evaluation was conducted in the same manner as in Examples 8-13 and 15-18.

(73) TABLE-US-00004 TABLE 4 Quantity Leakage Tracing Thick- Water vapor of heat amount of paper or ness permeability transfer carbon other paper m g/m.sup.2 .Math. 24 h W/ C. dioxide Example Tracing 20 7950 29000 27 paper Example Tracing 50 6600 13500 28 paper Example Tracing 3 16500 43000 29 paper Example Typewriter 20 6500 23000 X 30 paper Example Typewriter 50 5300 11000 X 31 paper Example Typewriter 10 10800 39500 X 32 paper Example Tracing 75 2100 6200 33 paper Example Tracing 5 17000 45000 X 34 paper
(Evaluation)

(74) It is clear from the results of Examples 27-29 and 30-34 that the total heat exchanging elements using the tracing paper type non-porous total heat exchanging element papers of the present invention are excellent in heat transferability, water vapor permeability and gas barrier property. It is clear that in the case of using porous type papers without using the tracing papers, when the thickness is increased or a binder is mixed to fill the pores, the leakage amount of carbon dioxide can be reduced, but simultaneously the water vapor permeability and the quantity of heat transfer decrease, and thus satisfactory total heat exchanging element papers cannot be obtained, and, besides, the leakage amount of carbon dioxide in the case of using the porous type papers is extremely greater than that in the case of using the non-porous total heat exchanging element papers of the present invention, and the gas barrier property of the porous type papers is considerably inferior to the papers of the present invention. Since the tracing paper type total heat exchanging element papers of the present invention are basically non-porous, even when the thickness is reduced, they have sufficient carbon dioxide barrier property, and by reducing the thickness, both water vapor permeability and quantity of heat transfer (heat exchangeability) are improved, resulting in the better total heat exchanging element papers. The total heat exchanging elements using the total heat exchanging element papers of the present invention satisfactorily perform exchanging of heat and water without causing mixing of air supplied from outside of a room and air discharged from inside of a room, and thus can provide high total heat exchanging function. Furthermore, the papers having a thickness within the range of the present invention can give good heat transferability, water vapor permeability and gas barrier property. If the thickness is more than that of the present invention, the gas barrier property is sufficient, but the heat transferability and the water vapor permeability are not sufficient, and thus the papers are not preferred as total heat exchanging element papers. If the thickness is less than that of the present invention, the gas barrier property is not sufficient probably because of formation of pin holes, and thus the papers are also not preferred as total heat exchanging element papers.

EXAMPLE 35

(75) A glassine paper having a basis weight of 20 g/m.sup.2 was coated with 9 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a glassine paper type total heat exchanging element paper 27. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 25 m.

EXAMPLE 36

(76) In the same manner as in Example 35, a glassine paper having a basis weight of 40 g/m.sup.2 was coated with 28 g/m.sup.2 of a diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a glassine paper type total heat exchanging element paper 28. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 50 m.

EXAMPLE 37

(77) In the same manner as in Example 35, a glassine paper having a basis weight of 8 g/m.sup.2 was coated with 4 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a glassine paper type total heat exchanging element paper 29. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 10 m.

EXAMPLE 38

(78) A typewriter paper having a basis weight of 16 g/m.sup.2 was coated with 10 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 30. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 20 m.

EXAMPLE 39

(79) In the same manner as in Example 38, a typewriter paper having a basis weight of 40 g/m.sup.2 was coated with 27 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a total heat exchanging element paper 31. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 50 m.

EXAMPLE 40

(80) In the same manner as in Example 38, an ultra-thin typewriter paper having a basis weight of 8 g/m.sup.2 was coated with 4 g/m.sup.2 in total of a 50 wt % diammonium phosphate solution and a 50 wt % lithium chloride solution as moisture absorbing agents, followed by drying to obtain a total heat exchanging element paper 32. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 10 m.

EXAMPLE 41

(81) A glassine paper having a basis weight of 75 g/m.sup.2 was coated with 45 g/m.sup.2 of a 50 wt % diammonium phosphate solution as a moisture absorbing agent, followed by drying to obtain a glassine paper type total heat exchanging element paper 33. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of not more than 5.010.sup.13 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially non-porous and had a thickness of 85 m.

EXAMPLE 42

(82) A glassine paper having a basis weight of 8 g/m.sup.2 was coated with 2.2 g/m.sup.2 of a 50 wt % diammonium phosphate solution and a lithium chloride solution as moisture absorbing agents, followed by drying to obtain a glassine paper type total heat exchanging element paper 34. This glassine paper type total heat exchanging element paper had a carbon dioxide permeation constant of more than 5.010.sup.11 mol.Math.m/m.sup.2.Math.s.Math.Pa measured in accordance with method A (differential pressure method) of JIS K7126, was substantially porous and had a thickness of 8 m.

(83) The total heat exchanging element papers produced in the above Examples were evaluated by the following evaluation methods. The results are shown in Table 5.

(84) (Water Vapor Permeability)

(85) Evaluation was conducted in the same manner as in Examples 1-7.

(86) (Quantity of Heat Transfer)

(87) Evaluation was conducted in the same manner as in Examples 1-7.

(88) (Barrier Property: Leakage Amount of Carbon Dioxide)

(89) Evaluation was conducted in the same manner as in Examples 8-13 and 15-18.

(90) TABLE-US-00005 TABLE 5 Quantity Leakage Glassine Thick- Water vapor of heat amount of paper or ness permeability transfer carbon other paper m g/m.sup.2 .Math. 24 h W/ C. dioxide Example Glassine 20 7000 23000 35 paper Example Glassine 50 5800 11500 36 paper Example Glassine 10 14000 35000 37 paper Example Typewriter 20 6500 23000 X 38 paper Example Typewriter 50 5300 11000 X 39 paper Example Typewriter 10 10800 39500 X 40 paper Example Glassine 75 2100 6200 41 paper Example Glassine 5 17000 45000 X 42 paper
(Evaluation)

(91) It is clear from the results of Examples 35-37 and 38-42 that the total heat exchanging elements using the glassine paper type non-porous total heat exchanging element papers of the present invention are excellent in heat transferability, water vapor permeability and gas barrier property. It is clear that in the case of using porous type papers without using the glassine papers, when the thickness is increased or a binder is mixed to fill the pores, the leakage amount of carbon dioxide can be reduced, but simultaneously the water vapor permeability and the quantity of heat transfer decrease, and thus satisfactory total heat exchanging element papers cannot be obtained, and, besides, the leakage of carbon dioxide is extremely greater than that in the case of using the non-porous total heat exchanging element papers of the present invention and the gas barrier property of the porous type papers is considerably inferior to the papers of the present invention. Since the glassine paper type total heat exchanging element papers of the present invention are basically non-porous, even when the thickness is made thin, they have sufficient carbon dioxide barrier property, and by reducing the thickness, both water vapor permeability and quantity of heat transfer (heat exchangeability) are improved, resulting in the better total heat exchanging element papers. The total heat exchanging elements using the total heat exchanging element papers of the present invention can satisfactorily perform exchanging of heat and water without causing mixing of air supplied from outside of a room and air discharged from inside of a room, and thus can provide high total heat exchanging function. Furthermore, the papers having a thickness within the range of the present invention can give good heat transferability, water vapor permeability and gas barrier property. If the thickness is more than that of the present invention, the gas barrier property is sufficient, but the heat transferability and the water vapor permeability are not sufficient, and thus the papers are not preferred as total heat exchanging element papers. If the thickness is less than that of the present invention, the gas barrier property is not sufficient probably because of formation of pin holes, and thus the papers are also not preferred as total heat exchanging element papers.

INDUSTRIAL APPLICABILITY

(92) According to the present invention, there can be provided excellent total heat exchanging element papers and total heat exchanging elements which are excellent in heat transferability, water vapor permeability and gas barrier properties and cause no mixing of supplied air and discharged air.