AGNIHOTRA is a gift to humanity from ancientmost Vedic sciences of bioenergy, medicine, agriculture and climate engineering.
Agnihotra is the process of purification of the atmosphere through the agency of fire prepared in a copper pyramid tuned to the biorhythm of sunrise/sunset. By practice of Agnihotra you will notice that tension on mind disappears and you begin to experience peace. The Mind is reshaped so nicely, so delicately, so effortlessly by sitting in Agnihotra atmosphere.

Following are some of the things told about Agnihotra in ancient science tradition.
Tremendous amounts of energy are gathered around the Agnihotra copper pyramid just at Agnihotra time. A magnetic type field is created, one which neutralizes negative energies and reinforces positive energies. Therefore a positive pattern is created by one who does Agnihotra merely by his/her performance.
When Agnihotra is performed, the Agnihotra smoke gathers particles of harmful radiation in the atmosphere and on a very subtle level neutralizes their radioactive effect. Nothing is destroyed, merely changed.
When Agnihotra fire is burnt there is not just energy from the fire but subtle energies are generated or thrust into the atmosphere by fire. Also consider the quality of materials burnt wherein lies the full effect of this healing HOMA. Much healing energy emanates form the Agnihotra pyramid.

Agnihotra renews the brain cells. It revitalizes the skin. It purifies the blood. It is the wholistic approach to life.
Agnihotra has the ability to neutralize pathogenic bacteria.
You sit at Agnihotra fire and breathe in the smoke which goes quickly into the bloodstream and lungs. This has excellent effect on circulatory system and even more so if Agnihotra ash is ingested. The smoke has a good effect on the brain and nervous system. 
If plants are placed in a room where vibration of Agnihotra pyramid fire are maintained, one subtle enough can actually see growth, communication, etc. Plants receive nutrition form Agnihotra atmosphere, become happy and grow well.
Just as Agnihotra pyramid fire gives nourishment to plants, it provides the same for human life and animals.
The sun brings or takes the energy which makes all conditions conducive to an antipollutionary change. It clams the world. The pyramid is the generator, the fire is the turbine. The cow dung, Ghee (clarified butter form cow's milk) and rice then interact to form a composition which is thrust, surrounds, neutralizes and nutritionalizes the material. Then, with organic substances, this provides the nutrients for survival, yield and propagation. This is how the Agnihotra fire physically heals the atmosphere.
Thousands of people on all continents belonging to different races, languages, religions and spiritual groups who practice Agnihotra have remarked that simply by performing daily HOMA, (i.e. Agnihotra at sunrise/sunset) they feel as if a protective film surrounds them.

PYRAMID: For Agnihotra you require a copper pyramid of specific size. Copper is a conductor. Just at morning Agnihotra all the electricities, energies, ethers are attracted to the pyramid in its shape. At sunset these energies are thrust out in same shape.

RICE: Brown rice. Highly polished rice loses nutritional value and hence brown rice. Only unbroken pieces of rice should be used for Agnihotra. If rice is broken the subtle energy structure is disturbed and hence is not fit for Agnihotra healing fire.

GHEE (clarified butter): Take some butter from cow's milk which has no additives and is pure. Heat it on low heat. After white solids have risen to the top pass the liquid through a fine strainer. What passes through is clarified butter (Ghee). This can last without refrigeration for a long time. Ghee is a very special medicinal substance. When used in Agnihotra fire it acts as a carrier agent for subtle energies. Powerful energy is locked up in this material.

DRIED COW DUNG: Take dung from male or female progeny of a cow. Make pancake-like patties and dry them in sun. Agnihotra fire is to be prepared from this dried cow dung.
Cow dung is treated as medicine in all ancient cultures whether they be Indians of North or South America, Scandinavians, East or West Europeans, Africans or Asians.

Place a flat piece of dried cow dung at the bottom of the copper pyramid. Arrange pieces of dried cow dung which have been coated with Ghee in the pyramid in such a manner as will allow air to pass. Apply a little Ghee to a small piece of cow dung and light it. Insert this lighted piece of cow dung in the pyramid. Soon all the dung in the pyramid will catch fire. You may use a hand fan to blow the air and help the flame. However, do not blow through the mouth to avoid bacteria from the mouth getting into the fire.
Do not use any mineral oil or similar material to start the fire. At sunrise and sunset a good flame should be ready in the pyramid. 

Take a few grains of rice in a dish or your left palm and apply a few drops of Ghee to them. 
Exactly at sunrise utter the first Mantra and after the word SWAHA add a few grains of rice (as little as you can hold in the pinch of your fingers will suffice) to the fire.

Utter the second Mantra and after the word SWAHA add a few grains of rice to the fire.

This completes morning Agnihotra.

At sunset do the same by using evening Mantras. This completes evening Agnihotra.

If you miss the timing it is not Agnihotra and you will not get the healing effect on the atmosphere or in the ash.

After each Agnihotra try to spare as many minutes as you can for meditation. You can sit at least till the fire extinguishes itself. Agnihotra creates medicinal and healing atmosphere.

Just before the next Agnihotra collect the ash and keep it in a glass or earthen container. It can be used for plants or making folk medicines.

There are vibrations that exist everywhere. It is only vibrations when you go into it. Where there is vibration there is also sound. When we do these Mantras, the sounds we utter activate these special vibrations that will create certain atmosphere or effects. Then the desired results are realized. These vibrations exist for everything, so anything can be activated, controlled or changed by Mantras.
When one with a pure mind speaks the Mantra into the Agnihotra pyramid at Agnihotra time, the ash retains that energy and the healing properties of the ash become more powerful.